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Palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin
International Journal of Coal Geology 50 (2002) 73 – 88 www.elsevier.com/locate/ijcoalgeo
Palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin Cortland F. Eble * Kentucky Geological Survey, Energy and Industrial Minerals Section, University of Kentucky, 288 Mining and Minerals Building, Lexington, KY 40506-0107, USA Received 21 November 2001; accepted 29 April 2002
Abstract Fossil spores and pollen have long been recognized as valuable tools for identifying and correlating coal beds. This paper describes the palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin with emphasis on forms that assist both intra- and interbasinal coal bed correlation. Stratigraphically important palynomorphs that originate in late Middle Pennsylvanian strata include Torispora securis, Murospora kosankei, Triquitrites minutus, Cadiospora magna, Mooreisporites inusitatus, and Schopfites dimorphus. Taxa that terminate in the late Middle Pennsylvanian include Radiizonates difformis, Densosporites annulatus, Dictyotriletes bireticulatus, Vestispora magna, and Savitrisporites nux. Species of Lycospora, Cirratriradites, Vestispora, and Thymospora, as well as Granasporites medius, Triquitrites sculptilis, and T. securis end their respective ranges slightly higher, in earliest Late Pennsylvanian age strata. Late Middle Pennsylvanian and earliest Late Pennsylvanian strata in the Appalachian Basin correlate with the Radiizonates difformis (RD), Mooreisporites inusitatus (MI), Schopfites colchesterensis – S. dimorphus (CP), and Lycospora granulata – Granasporites medius (GM) spore assemblage zones of the Eastern Interior, or Illinois Basin. In the Western Interior Basin, these strata correlate with the middle-upper portion of the Torispora securis – Laevigatosporites globosus (SG) and lower half of the Thymospora pseudothiessenii – Schopfites dimorphus (PD) assemblage zones. In western Europe, late Middle Pennsylvanian and earliest Late Pennsylvanian strata correlate with the middle-upper portion of the Torispora securis – T. laevigata (SL) and the middle part of the Thymospora obscura – T. thiessenii (OT) spore assemblage zones. Allegheny Formation coal beds also correlate with the Torispora securis (X) and Thymospora obscura (XI) spore assemblages, which were developed for coal beds in Great Britain. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Pennsylvanian; Palynology; Appalachian Basin; Westphalian; Desmoinesian
1. Introduction Coal palynology has long been of value in helping to identify and correlate Pennsylvanian-age coal-bear-
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ing strata. This technique primarily relies on the identification of stratigraphically constrained palynotaxa, although some beds can be identified and separated from adjacent beds, based on the relative abundance of otherwise common, long-ranging forms. Coal palynology is also a useful tool in reconstructing the ancient floras that inhabited late Carboniferous mires (Kosanke, 1943, 1950, 1973, 1988a,b,c;
0166-5162/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 6 - 5 1 6 2 ( 0 2 ) 0 0 11 4 - 3
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Peppers, 1964, 1970, 1979, 1984, 1996; Peppers and Popp, 1979; Eble, 1988, 1996a,b; Eble and Grady, 1990, 1993; Willard, 1994). This paper focuses on the palynology of late Middle Pennsylvanian coal beds from the Appalachian Basin and discusses the criteria used to identify and correlate individual coal beds and coal zones, both on an intra- and interbasinal scale. Palynology is an especially important correlation tool in the Appalachian Basin, which is dominated by lithologies of terrestrial origin, and as such, has limited potential for marine macro- and microfaunal bed identification and correlation.
2. Previous work The earliest attempts to use fossil spores and pollen as a correlation tool in the Appalachian Basin were done with coal thin sections by Rheinhardt Thiessen and his co-workers at the United States Bureau of Mines (e.g., Thiessen and Staud, 1923; Thiessen and Wilson, 1924). Early palynological studies of Appalachian coals that utilized the maceration method include those by Kosanke (1943), who reported on the palynology of the Pomeroy (Redstone) and Pittsburgh coals of eastern Ohio; Cross (1947) and Cross
Fig. 1. Coal bed stratigraphy of the study interval. Note that Formation and Group nomenclature is not uniform. For example, in northern West Virginia, western Pennsylvania, and Ohio, late Middle Pennsylvanian-age coal beds are assigned to the Allegheny Formation, while older coal beds (Mercers, Quakertown, and Vandusen) are assigned to the Pottsville Group. Late Pennsylvanian coal beds in this area (Bakerstown, Brush Creek, and Mahoning) are assigned to the Glenshaw Formation of the Conemaugh Group. In contrast, late Middle Pennsylvanian coal beds in southern West Virginia are assigned to the Charleston Sandstone, with older coals (Stockton, Coalburg, and Winifrede) being assigned to the Kanawha Formation. Late Pennsylvanian strata in this area are assigned to the Conemaugh Formation. In northeastern Kentucky, late Middle Pennsylvanian coal beds are assigned to the Princess Formation. Older coals (Princess Nos. 3 and 4) are assigned to the Four Corners Formation, and younger Late Pennsylvanian coal beds (Brush Creek, Bakerstown) are assigned to the Conemaugh Formation.
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and Schemel (1952), who described the characteristic small spore floras of eastern Kentucky and southern West Virginia coals; and Cropp (1963) who documented the palynofloras of several Lower and Middle Pennsylvanian Tennessee coal beds. Several studies have focused on the palynology of late Middle Pennsylvanian (Allegheny Formation and equivalent, Fig. 1) coals, and thus are of particular value in the present work. These include: Denton (1957), who correlated Lower Allegheny Formation coal beds in Columbiana County, Ohio with adjacent areas; Schemel (1957), who characterized the small spore assemblages of some Middle Pennsylvanian-age coals in West Virginia and surrounding areas; and Frederiksen (1961), who documented the palynology of the Brookville coal in western Pennsylvania. Studies of the Lower Kittanning coal bed include those by Riffelmacher (1952) and Habib (1965, 1966) in western Pennsylvania, and Gray (1967) in east central
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Ohio. Kosanke (1973, 1984, 1988a,b,c) reported on the palynology of late Middle Pennsylvanian coals from the Princess Coal Reserve District in northeastern Kentucky, and from the proposed Pennsylvanian System stratotype area in southern West Virginia. Helfrich (1981) studied some late Middle Pennsylvanian coals from drill cores in northeastern Kentucky, and made some preliminary correlations using palynomorphs. More recently, Kosanke and Cecil (1996) have discussed the palynofloral changes that occur across the late Middle to early Late Pennsylvanian transition, and its significance in terms of climate change in the Appalachian Basin.
3. Materials and methods Samples of coal were collected from three sections that expose late Middle Pennsylvanian strata. They
Fig. 2. Location map for the sections used in this study. Refer to Fig. 1 for the stratigraphic position of coal beds sampled in each section. The stippled area is the approximate outline of coal-bearing strata of Pennsylvanian age in the Appalachian Basin.
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are: (1) the Chestnut Ridge/Interstate 68 section near Morgantown, West Virginia, (2) the Powell Mountain section at Birch River, West Virginia, and (3) the Interstate 64 section in northeastern Kentucky (Fig. 2). A list of the samples used in this study is presented in Appendix A. All samples were first mechanically crushed to a maximum particle size of 1 mm and riffled to obtain a representative subsplit of approximately 50 g. A total of 5 g of coal were oxidized with Schulze’s Solution (concentrated nitric acid saturated with potassium chlorate), digested with a 5% solution of potassium hydroxide, screened with a 250-mm mesh screen to remove coarse debris, and concentrated with zinc chloride (specific gravity 1.9). Residues were dehydrated with cellosolve (2-ethoxyethanol), and mounted on 75 25 mm microscope slides (30 22 mm cover glasses) with Canada balsam. Counts of 250 palynomorphs/sample were employed to determine the relative abundance of spore taxa, with the remainder of the slide being scanned with a low-power objective to record any forms not encountered during the statistical counts. Extra coal, maceration residues, and slides generated from this study are housed at the Kentucky Geological Survey in Lexington, KY.
4. Results 4.1. Chestnut Ridge section The late Middle Pennsylvanian Allegheny Formation is exposed in northern West Virginia where Interstate 68 transects the Chestnut Ridge anticline (between mile posts 10 and 16; see Fonner et al., 1981). In stratigraphically descending order, the coals that were sampled are the Upper Freeport, Lower Freeport, Upper, Middle, and Lower Kittanning, and an unnamed coal below the Lower Kittanning (Fig. 3). All of the Allegheny Formation coals in this section are co-dominated by tree fern spores and Lycospora, the spore produced by many of the large lycopod trees which were a conspicuous element in Early and Middle Pennsylvanian mires. The most common species of Lycospora are Lycospora granulata and L. pusilla. Tree fern spore diversity was at its apex during the late Middle Pennsylvanian, with several species being recognized. These include Punctatisporites minutus,
Punctatosporites minutus, Punctatosporites rotundus, Laevigatosporites minimus, Thymospora pseudothiessenii, Laevigatosporites globosus, Punctatosporites granifer, and Torispora securis. Stratigraphically important taxa in this section include the occurrence of Murospora kosankei, Mooreisporites inusitatus, Triquitrites minutus, T. securis, and T. pseudothiessenii in all of the Allegheny Formation coal beds in the section. Schopfites dimorphus is restricted to the Lower, Middle, and Upper Kittanning coal beds, and the Middle Kittanning coal marks the last occurrence of Densosporites. The Upper Freeport coal bed is the last coal in the section that contains Lycospora, Granasporites medius, Thymospora pseudothiessenii, Triquitrites sculptilis, Torispora securis, Murospora kosankei, Mooreisporites inusitatus, Cirratriradites, and Vestispora. Elsewhere in the Appalachian Basin, these taxa terminate in the overlying Mahoning coal, which is the next coal in stratigraphic sequence above the Upper Freeport coal. The Upper Freeport and Mahoning coals have essentially identical palynofloras (Schemel, 1957; DiMichele et al., 1996; Peppers, 1996). The Chestnut Ridge section occurs in an area where the interval between the Lower Kittanning coal and the top of the underlying Pottsville Group is quite thin ( < 15 m). This implies that the structural activity associated with the Chestnut Ridge anticline was penecontemporaneous with deposition of Allegheny sediments. However, in other areas of northern West Virginia, northeastern Ohio, and western Pennsylvania, this interval is much thicker (>75 m) and includes additional coal beds not present in the Chestnut Ridge section. Analyses of these coals (Schemel, 1957; Denton, 1957; Frederiksen, 1961; Peppers, 1996) indicate that Thymospora pseudothiessenii, Mooreisporites inusitatus, and Triquitrites minutus all extend down to the level of the Upper Mercer coal bed (Fig. 1). In addition, Torispora securis was found in the underlying Middle Mercer (Peppers, 1996) and Quakertown (Eble, unpublished data) coal beds, the latter being sampled from its ‘‘type’’ locality on Quakertown run near Lowellville, Ohio. 4.2. Birch River section Strata assigned to the Charleston Sandstone are exposed near the town of Birch River in southern
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Fig. 3. Distribution of numerically significant miospore taxa, grouped together according to affinity, in Allegheny Formation coal beds collected from the Chestnut Ridge section in northern West Virginia.
West Virginia where US Route 19 transects Powell Mountain. The name Charleston Sandstone was proposed by Campbell and Mendenhall (1896) for strata bounded by the Kanawha Black Flint at the base and red and green shales considered to mark the base of the Conemaugh Formation at the top. The unit is bestdeveloped in the immediate vicinity of Charleston, West Virginia, and is composed of approximately 70% or more sandstone that occurs in thick, coalescing sequences (Arndt, 1979). In stratigraphically descending order, the coal beds that were sampled are the No. 7 Block, No. 6 Block, No. 5 Block, Little No. 5 Block, and Stockton ‘‘A’’. In addition, three additional coals, the Stockton, Coalburg, and Winifrede, were sampled from the underlying Kanawha Formation (Fig. 4).
All of the sampled coals are dominated, or codominated, by Lycospora and tree fern spores. The Winifrede, Coalburg, and Stockton contain similar assemblages with the notable presence of Radiizonates difformis. Coal beds older than the Winifrede do not contain R. difformis (Kosanke, 1984, 1988a,b; Eble, 1996a,b). The Stockton coal also marks the first appearance of Torispora securis, which occurs in much higher percentages in the overlying Stockton ‘‘A’’ coal. The Little No. 5 Block coal occurs in two benches in the Birch River section and marks the first occurrence of Murospora kosankei, Triquitrites minutus, Mooreisporites inusitatus, and Cadiospora magna in the Birch River section. The overlying No. 5 Block coal, which also occurs in two splits (called Upper and
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Fig. 4. Distribution of numerically significant miospore taxa, grouped together according to affinity, in the Birch River section in southern West Virginia.
Lower No. 5 Block), is an important horizon as it marks the last occurrence of Radiizonates difformis, Densosporites annulatus, Savitrisporites nux, Vestispora magna, and Dictyotriletes bireticulatus. The Upper No. 5 Block coal also contains the first record of Thymospora pseudothiessenii and T. obscura, which helps to differentiate the two benches. The No. 6 Block coal bed is the only coal in the Birch River section that contains Schopfites dimorphus. Although the No. 5 Block coal has been historically correlated with the Lower Kittanning coal of northern West Virginia and western Pennsylvania (e.g., Wanless, 1939), spore assemblages from the Lower Kittanning more closely resemble those from the No. 6 Block coal (Kosanke, 1984). The highest coal in the section, the No. 7 Block coal bed, contains a miospore assemblage similar to those obtained from
the Upper and Lower Freeport coals in the Chestnut Ridge section. Of particular note are relatively high percentages (8%) of Triquitrites in the No. 7 Block coal. 4.3. Interstate 64 section Late Middle Pennsylvanian strata assigned to the Princess Formation are exposed along a series of roadcuts between mileposts 173 and 191 on Interstate 64 in northeastern Kentucky (Fig. 2) (Chesnut, 1992). Sampled coal beds include the Princess No. 5 through Princess No. 9 coal beds (Fig. 5). Two stratigraphically older coals assigned to the Four Corners Formation, the Princess No. 3 and Princess No. 4, were also sampled and analyzed (Fig. 6). Collectively, the Princess No. 3 through Princess No. 9 coal beds all
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Fig. 5. Distribution of numerically significant miospore taxa, grouped together according to affinity, from coals in the Princess No. 5 through Brush Creek coal beds in the Interstate 64 section in northeastern Kentucky.
contain miospore assemblages co-dominated by Lycospora and tree fern spores. Stratigraphically important taxa in the Princess No. 3 coal bed include Radiizonates difformis, Laevigatosporites globosus, and Triquitrites sculptilis. The Princess No. 3 coal bed marks the beginning of the range zone of R. difformis in northeastern Kentucky, whereas the latter two forms both originate in slightly older coals. The distinctive monolete spore Torispora securis is first seen in the overlying Princess No. 4 coal bed. The Princess No. 5 coal marks the last appearance of Radiizonates difformis. As such, the range of R. difformis in northeastern Kentucky is known to extend from the Princess No. 3 coal to Princess No. 5 coal. A prior study of the Richardson coal in southeastern Kentucky (Hower et al., 1994), which is correlative with the Princess No. 5 (Rice and Hiett, 1994), also
recorded the presence of Radiizonates difformis. Other palynomorphs that terminate in the Princess No. 5 coal are Densosporites annulatus, Vestispora magna, Savitrisporites nux, and Dictyotriletes bireticulatus. The Princess No. 5 coal also marks the first appearance of Triquitrites minutus, Murospora kosankei, Mooreisporites inusitatus, and (sporadic) Cadiospora magna. The Princess No. 5 is overlain by two thin, laterally discontinuous coals, the Princess No. 5a and No. 5b coal beds (Figs. 1 and 5). In places, these two coals are bounded by the Kilgore Flint Member (Rice et al., 1994), which underlies the Princess No. 5a coal, and the Obryan limestone above the 5b coal (Rice et al., 1992), which may be equivalent with the Vanport Limestone of south central Ohio (Ferm, 1963). The Princess No. 5a coal bed contains the first occurrences of Thymospora pseudothiessenii, T. obscura, and
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Fig. 6. Distribution of numerically significant miospore taxa, grouped together according to affinity, from the Princess No. 3 and No. 4 coal beds in the Interstate 64 section in northeastern Kentucky.
Schopfites carbondalensis. A thick, well-developed paleosol separates the Princess No. 5b from the Princess No. 6. This paleosol, known locally as the Hitchens clay bed, is one of the most laterally extensive claystones in the area. Palynologically, the Princess No. 6 coal bed marks the first occurrence of Schopfites dimorphus. S. dimorphus has a very limited range in northeastern Kentucky, occurring in only the Princess No. 6 and No. 7 coal beds (Kosanke, 1973). As such, it is an extremely useful palynomorph for bed identification and correlation. The Princess No. 7 coal bed also marks the last sporadic occurrence of Densosporites. The overlying Princess No. 8 and No. 9 coal beds are palynologically indistinguishable, with the Princess No. 8 coal marking the last occurrences of Murospora kosankei and Mooreisporites inusitatus. Likewise, the overlying Princess No. 9 coal bed contains the last occurrences of Lycospora, Granasporites medius, Cirratriradites,
Thymospora pseudothiessenii, Torispora securis, Vestispora, and Triquitrites sculptilis in the Interstate 64 section. The next coal in stratigraphic sequence, the Brush Creek coal bed, contains a noticeably different palynoflora that is devoid of Lycospora (Fig. 5).
5. Correlation within the Appalachian Basin Wanless (1939) correlated Princess Formation coals of northeastern Kentucky with Allegheny Formation coals of eastern Ohio and western Pennsylvania as follows: Kentucky Princess Princess Princess Princess
No. No. No. No.
Ohio and Pennsylvania 9 8 7 6
Upper Freeport coal Lower Freeport coal Middle Kittanning coal Lower Kittanning coal
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Although largely based on lithostratigraphy, these correlations are supported by palynological data derived from the present investigation and also from earlier reports (Kosanke, 1973, 1984, 1988a,b). Fig. 7 shows the correlation of coal beds in the three studied sections, which is based on the ranges of certain palynotaxa. For example, Schopfites dimorphus only occurs in the Princess No. 6 and No. 7 coal beds in northeastern Kentucky, whereas in adjacent Ohio (Gray, 1967; Rice et al., 1994), Schopfites dimorphus is confined to the Lower and Middle Kittanning coal beds. In northern West Virginia and western Pennsylvania, the range of Schopfites dimorphus is in the Lower, Middle, and Upper Kittanning coal beds. Likewise, the Princess No. 7 coal represents the last occurrence of Densosporites and Schopfites dimorphus in northeastern Kentucky, whereas in Ohio
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(Denton, 1957; Gray, 1967), northern West Virginia, and western Pennsylvania, the last occurrence of Densosporites is in the Middle Kittanning coal bed. The proposed lithostratigraphic correlation of the Princess No. 8 and No. 9 coals with the Lower and Upper Freeport coals seems reasonable, as the beds are palynologically very similar. Likewise, the Brush Creek coal in Kentucky appears palynologically identical to the Brush Creek coal of northern West Virginia, Pennsylvania, and Ohio (Eble, unpublished data). Other palynological correlations are also warranted. The last occurrence of Radiizonates difformis in the Princess No. 5 coal bed of northeastern Kentucky, the Lower No. 5 Block coal of southern West Virginia, the Richardson coal of southeastern Kentucky, and the Newland coal bed in southeastern Ohio (Rice et al., 1994; Eble, unpublished data, see Fig. 1)
Fig. 7. Range chart for stratigraphically important palynomorphs identified from the Chesnut Ridge, Birch River, and Interstate 64 sections.
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indicates that these beds are correlative. Likewise, the first occurrence of Thymospora pseudothiessenii in the Princess No. 5a coal bed of northeastern Kentucky, the Upper No. 5 Block coal bed in southern West Virginia, and the Ogan coal bed of southeastern Ohio indicates that these beds are regional correlatives (Fig. 1). Correlation of this interval with more northern areas (northeastern Ohio, western Pennsylvania, northern West Virginia) is problematic as Radiizonates difformis has not been identified from coals in the lower part of the Allegheny Formation, or the upper part of the Pottsville Group in the Northern Appalachian Basin. Furthermore, Thymospora pseudothiessenii has been identified from coals in the Upper Pottsville Formation (Peppers, 1996) (Mercer coal beds, see Fig. 1), well below the level of the Lower Kittanning coal bed. This contrasts greatly with the first occurrence of Thymospora pseudothiessenii in the Central Appalachian Basin (eastern Kentucky, southeastern Ohio, and southern West Virginia), which is immediately below the Lower Kittanning coal bed (and equivalents). Collectively, these disparities make the Lower Allegheny coals in the Northern Appalachian Basin appear ‘‘younger’’ than their Central Appalachian Basin counterparts, an observation that was noted earlier by Schemel (1957). One possibility is that range zones of Thymospora pseudothiessenii and Radiizonates difformis simply differ between the two areas, and as such cannot be used to correlate coals between the two areas. Another possibility, however, is that the Lower Allegheny (pre-Lower Kittanning coal) interval in the Central Appalachian Basin is, in fact, older than the same interval in the Northern Appalachian Basin. If true, then the thick, laterally extensive paleosol beneath the Lower Kittanning coal bed (and equivalents) actually represents a substantial unconformity, a concept postulated earlier by Arkle (1974). Torispora securis is first seen in the Princess No. 4 coal bed of northeastern Kentucky and Stockton coal bed of southern West Virginia, which are considered to be correlative. The first occurrence of Torispora securis in southeastern Ohio has not been positively identified, but probably is in one of the Mercer coal beds (Fig. 1). In the Northern Appalachian Basin, Torispora securis has been identified in the Quakertown coal bed collected from its ‘‘type’’ area (Fig. 1), although it is unknown if this represents the range
base for Torispora securis. Based on the first occurrence of Radiizonates difformis, the Princess No. 3 coal bed of northeastern Kentucky is correlative with the Vandusen coal bed of southeastern Ohio (Rice et al., 1992, 1994, see Fig. 1). The Princess No. 3 coal bed is also correlated with the Coalburg coal bed of southern West Virginia. As mentioned previously, Radiizonates difformis has not been identified in Northern Appalachian Basin coal beds.
6. Comparison of spore assemblages with other areas Peppers (1984, 1996) constructed 11 miospore assemblage zones for Pennsylvanian-age coal beds in the Eastern Interior (Illinois) Basin. Likewise, Ravn (1986) palynologically subdivided Pennsylvanian-age Western Interior Basin coals in Iowa into four assemblage zones. Carboniferous coal beds in Great Britain were studied and palynologically zonated by Smith and Butterworth (1967). Likewise, Carboniferous coal beds and sediments in western Europe were palynologically zonated by Clayton et al. (1977) (Fig. 8). More recently, Owens (1996) has summarized the more important palynological events for late Carboniferous strata in the Northern Hemisphere. Collectively, these palynomorph zonations provide a convenient basis for comparing the results of the present study with other areas. The Winifrede to No. 5 Block coal interval best compares with the Radiizonates difformis (RD) and Cadiospora magna – Mooreisporites inusitatus (MI) spore assemblage zones of the Eastern Interior Basin (Peppers, 1984, 1996). In the Western Interior Basin (Ravn, 1986), this interval correlates with the middle to upper portion of the Torispora securis –Laevigatosporites globosus (SG) assemblage zone, with the break between the Torispora securis –Laevigatosporites globosus/Dictyotriletes bireticulatus (SGb) and the Torispora securis – Laevigatosporites globosus/ Murospora kosankei (SGk) assemblage subzones occurring at the level of the Little No. 5 Block coal (Fig. 8). When compared with British coal beds (Smith and Butterworth, 1967; Clayton et al., 1977; Owens, 1996), the Winifrede and Coalburg coal beds conform to the Vetispora magna (IX) spore assemblage, while the Stockton to No. 5 Block coal interval
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Fig. 8. Correlation chart for the Appalachian, Eastern Interior, and Western Interior Basins using published miospore assemblage zones. Western Interior Basin assemblage zones are from Ravn (1986), while Eastern Interior Basin Assemblage zones are from Peppers (1984, 1996). Miospore assemblage zones for British coal beds are from Smith and Butterworth (1967), and the assemblages for western Europe are from Clayton et al. (1977). Range zone acronyms (e.g., OT and SL) are explained in the text.
correlates with the overlying Torispora securis (X) assemblage zone (Smith and Butterworth, 1967). The Winifrede to No. 5 Block coal interval also correlates with the Torispora securis– Torispora laevigata (SL) spore assemblage zone of western Europe (Clayton et al., 1977) (Fig. 8). The next interval in vertical succession, the Kittanning coal bed (and equivalents) interval, is palynologically well constrained. The Kittanning coal interval correlates with Schopfites colchesterensis – S. dimorphus (CP) spore assemblage zone of the Eastern Interior Basin (Peppers, 1984, 1996), the Thymospora pseudothiessenii –Schopfites dimorphus/ Densosporites triangularis (PDt) assemblage subzone of the Western Interior Basin (Ravn, 1986), and the lower part of the Thymospora obscura –T. thiessenii
(OT) spore assemblage zone of western Europe (Clayton et al., 1977) (Fig. 8). The Kittanning coal interval also correlates with the Thymospora obscura (XI) assemblage zone of Smith and Butterworth (1967) (Fig. 8). The Lower Freeport, Upper Freeport and Mahoning coal beds are the last coals in the Appalachian Basin that contain Lycospora. Several other taxa, including Granasporites medius, Thymospora pseudothiessenii, Triquitrites sculptilis, Torispora securis, Cirratriradites, and Vestispora, also end their ranges in these coals. The Lower Freeport through Mahoning coal beds best compare with the Lycospora granulata –Granasporites medius (GM) spore assemblage zone of the Eastern Interior Basin (Peppers, 1984, 1996), the Thymospora pseudothiessenii –Schopfites
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dimorphus/Triquitrites spinosus (PDs) assemblage subzone of the Western Interior Basin (Ravn, 1986), and the upper-middle portion of the Thymospora obscura– T. thiessenii spore assemblage zone of western Europe (Clayton et al., 1977). The Lower Freeport through Mahoning coal bed interval also correlates with the Thymospora obscura (XI) assemblage zone of Smith and Butterworth (1967) (Fig. 8). The stratigraphically youngest coals examined in this study, the Brush Creek and Bakerstown, contain palynofloras that correlate with the Punctatisporites minutus – P. obliquus (MO) miospore assemblage zone of the Eastern Interior Basin (Peppers, 1985; Peppers, 1996) and the upper part of the Thymospora obscura – T. thiessenii spore assemblage zone of western Europe (Clayton et al., 1977). No equivalent assemblages have been documented from the Western Interior Basin (Ravn, 1986) or from the coal fields of Great Britain (Smith and Butterworth, 1967).
7. Summary Palynomorphs are an important tool for identification, and correlation, of late Middle Pennsylvanian coal-bearing strata in the Appalachian Basin. Stratigraphically important forms that have their origins in the lower part of the Allegheny Formation (and equivalents) include Torispora securis, Murospora kosankei, Triquitrites minutus, Cadiospora magna, Mooreisporites inusitatus, Thymospora pseudothiessenii, and Schopfites dimorphus. Forms that end their ranges in the lower to middle part of the Allegheny Formation include Radiizonites difformis, R. rotatus, Densosporites annulatus, Dictyotriletes bireticulatus, Vetispora magna, and Savitrisporites nux. Lycospora, Granasporites medius, Thymospora pseudothiessenii, Triquitrites sculptilis, Torispora securis, Cirratriradites, and Vestispora end their ranges near the top of the Allegheny Formation (Fig. 7). The recognition of these taxa helps facilitate correlation of coal beds within the central part of the Appalachian Basin, which is important because coal nomenclature in this area is inconsistent (see Fig. 1). Correlation of lower Allegheny Formation coals (i.e., below the level of the Lower Kittanning coal and equivalents) in the Central Appalachian Basin with more northern areas is uncertain mainly because of
differences in the range zones Thymospora and Radiizonates. In the Central Appalachian Basin, Thymospora pseudothiessenii is first seen just below the level of the Lower Kittanning coal, whereas to the north, it occurs throughout the Allegheny Formation, and is even seen in late Pottsville Group coals. In the Central Appalachian Basin, R. difformis occurs up to a level just below the introduction of Thymospora (e.g., Lower No. 5 Block coal), and hence persists throughout most of the lower Allegheny Formation. In more northern areas, however, Radiizonates is completely absent in Allegheny Formation coal beds. Collectively, these range disparities make the lower part of the Allegheny Formation in the Central Appalachian Basin appear ‘‘older’’ than the same interval to the north. Palynology also assists interbasinal correlation of late Middle Pennsylvanian strata. In the Illinois Basin, Allegheny Formation (and equivalent) coals best compare with the Radiizonates difformis (RD), Cadiospora magna – Mooreisporites inusitatus (MI), Schopfites colchesterensis – Thymospora pseudothiessenii (CP), and Lycospora granulata – Granasporites medius (GM) miospore assemblage zones of the Eastern Interior Basin. Allegheny Formation coals also compare with the Torispora securis – Laevigatosporites globosus (SG) and Torispora pseudothiessenii – Schopfites dimorphus (PD) miospore assemblage zones of the Western Interior Basin, and the upper portion of the Torispora securis –T. laevigata (SL) and lower two-thirds of the Thymospora obscura – T. thiessenii (OT) spore assemblage zone of western Europe (Clayton et al., 1977). When compared to British coal beds, Allegheny Formation coal beds correlate with the Vestispora magna (IX), Torispora securis (X), and Thymospora obscura (XI) miospore assemblage zones of Smith and Butterworth (1967) (Fig. 8).
Acknowledgements Bill Grady, Nick Fedorko, and Mitch Blake, all with the West Virginia Geological and Economic Survey in Morgantown, WV, are thanked for providing the author with samples from the Birch River section, and also for numerous discussions regarding Allegheny Formation/Charleston Sandstone stratigraphy.
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Don Chesnut and Steve Greb, both with the Kentucky Geological Survey in Lexington, KY, are thanked for helping with the collection of the Interstate 64 section, and also for sharing their knowledge of Pennsylvanian-age rocks in Kentucky. Thanks go to Charles Rice, retired from the United States Geological Survey, who collected and forwarded samples of the Winters, Ogan and Newland coal beds from southeastern Ohio. Likewise, Ernie Slucher, of the Ohio Geological Survey, is thanked for collecting and forwarding a sample of the Quakertown coal bed from its type location in northeastern Ohio. Last, but certainly not least, this manuscript was greatly improved by the careful and thoughtful reviews of Bill DiMichele, of the Smithsonian Institution, Andrew Scott, of Royal Holloway and Bedford College, University of London, and Jim Hower, of the Center for Applied Energy Research in Lexington, KY.
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Birch River section—Along US Route 19 from the town of Birch River to the top of Powell Mountain in Nicholas County, West Virginia. The section is in the Widen 7.5-min quadrangle. Coal beds in Fig. 4
Thickness (m) 0.07 0.63 0.41 0.08
Appendix A. List of coal samples
No. 7 Block No. 6 Block (bench 1) No. 6 Block (bench 2) Upper No. 5 Block (0.0 – 0.08 m top of bed, bench 1) Upper No. 5 Block (0.08 – 0.19 m, bench 2) Upper No. 5 Block (0.19 – 0.33 m, bench 3) Upper No. 5 Block (0.33 – 0.45 m, bench 4) Upper No. 5 Block (0.45 – 0.63 m, base of bed, bench 5) Lower No. 5 Block Little No. 5 Block (upper split) Little No. 5 Block (lower split) Stockton ‘‘A’’ (0.0 – 0.53 m, bench 1) Stockton ‘‘A’’ (0.53 – 1.63 m, bench 2) Stockton Coalburg Winifrede
Chestnut Ridge section—Between mileposts 10 and 16 on Interstate 68 in northern (Monongalia and Preston Counties) West Virginia. The section is in the Lake Lynn 7.5-min quadrangle.
Interstate 64 section—Between mileposts 173 and 191 along Interstate 64 in northeastern Kentucky. The section is in the Grayson, Rush, Bolts Fork, Ashland, and Catlettsburg 7.5-min quadrangles.
Coal beds in Fig. 3
Thickness (m)
Upper Freeport (0.0 – 0.15 m, top of bed, bench 1) Upper Freeport (0.15 – 0.45 m, bench 2) Upper Freeport (0.45 – 0.75 m, bench 3) Upper Freeport (0.75 – 1.05 m, bench 4) Upper Freeport (1.05 – 1.35 m, base of bed, bench 5) Lower Freeport (0.0 – 0.3 m, split 1, bench 1) Lower Freeport (0.3 – 0.57 m, split 1, bench 2) Lower Freeport (split 2) Lower Freeport (split 3) Lower Freeport (0.0 – 0.23 m split 4, bench 1) Lower Freeport (0.23 – 0.61 m, split 4, bench 2) Lower Freeport (0.61 – 0.91 m, split 4, bench 3) Upper Kittanning (0.18 m, split 1) Upper Kittanning (0.27 m, split 2) Middle Kittanning (split 1) Middle Kittanning (split 2) Lower Kittanning (split 1) Lower Kittanning (split 2) unnamed Allegheny Fm coal
0.15 0.3 0.3 0.3 0.3 0.3 0.27 0.43 0.18 0.23 0.38 0.3 0.18 0.27 0.3 0.15 0.3 0.17 0.33
0.11 0.14 0.12 0.18 1.52 0.37 0.29 0.53 1.1 0.83 0.85 0.44
Coal beds in Fig. 5
Thickness (m)
Brush Creek Princess No. 9 Princess No. 8 (0.0 – 0.14 m, top of bed, bench 1) Princess No. 8 (0.14 – 0.27 m, bench 2) Princess No. 8 (0.27 – 0.42 m, bench 3) Princess No. 8 (0.42 – 0.57 m, base of bed, bench 4) Princess No. 7 (0.0 – 0.15 m, top of bed, bench 1) Princess No. 7 (0.15 – 0.30 m, bench 2) Princess No. 7 (0.30 – 0.45 m, bench 3) Princess No. 7 (0.45 – 0.6 m, bench 4) Princess No. 7 (0.6 – 0.75 m, base of bed, bench 5) Princess No. 6 Princess No. 5b Princess No. 5a Princess No. 5 (split 1) Princess No. 5 (split 2) Princess No. 5 (split 3) Princess No. 5 (split 4) Princess No. 5 (split 5)
0.3 0.08 0.14 0.13 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.41 0.38 0.08 0.36 0.13 0.3 0.05 0.04
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Coal beds in Fig. 6
Thickness (m)
Princess Princess Princess Princess Princess Princess Princess Princess
0.32 0.16 0.34 0.27 0.13 0.34 0.4 0.15
No. No. No. No. No. No. No. No.
4 3 3 3 3 3 3 3
Appendix B. Formal systematic nomenclature for palynomorph taxa discussed in the text Murospora kosankei Somers, 1952 Triquitrites minutus Alpern, 1958 Cadiospora magna Kosanke, 1950 Mooreisporites inusitatus (Kosanke) Neves, 1958 Schopfites dimorphus Kosanke, 1950 Radiizonates difformis (Kosanke) Staplin and Jansonius, 1964 Densosporites Berry emend. Butterworth et al., 1964 Densosporites annulatus (Loose) Schopf et al., 1944 Dictyotriletes bireticulatus (Ibrahim) Potonie´ and Kremp emend. Smith and Butterworth, 1967 Vestispora magna (Butterworth and Williams) Spode (in Smith and Butterworth, 1967) Savitrisporites nux (Butterworth and Williams) Sullivan emend. Smith and Butterworth, 1967 Lycospora Schopf, Wilson and Bentall emend. Potonie´ and Kremp, 1954 Cirratriradites Wilson and Coe, 1940 Vestispora Wilson and Hoffmeister emend. Wilson and Venkatachala, 1963 Thymospora Wilson and Venkatachala, 1963 Thymospora pseudothiessenii (Kosanke) Wilson and Venkatachala, 1963 Thymospora obscura (Kosanke) Wilson and Venkatachala, 1963 Granasporites medius Alpern emend. Ravn et al., 1986 Triquitrites sculptilis Balme emend. Smith and Butterworth, 1967 Torispora securis Balme emend. Alpern et al., 1965 Punctatisporites minutus Kosanke emend. Peppers, 1964 Punctatosporites minutus Ibrahim emend. Alpern and Doubinger, 1973 Punctatosporites rotundus Bharadwaj emend. Alpern and Doubinger, 1973 Laevigatosporites minimus (Wilson and Coe) Schopf et al., 1944 Laevigatosporites globosus Schemel, 1951 Punctatosporites granifer Potonie´ and Kremp emend. Alpern and Doubinger, 1973
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C.F. Eble / International Journal of Coal Geology 50 (2002) 73–88 Appalachian Basin. In: Jansonius, J., McGregor, D.C. (Eds.), Palynology: Principles and Applications. Vegetational History, vol. 3. American Association of Stratigraphic Palynologists Foundation, pp. 1143 – 1156, chapter 29. Eble, C.F., Grady, W.C., 1990. Paleoecological interpretation of a Middle Pennsylvanian coal bed in the Central Appalachian Basin, USA. International Journal of Coal Geology 16, 255 – 286. Eble, C.F., Grady, W.C., 1993. Palynologic and petrographic characteristics of two Middle Pennsylvanian coal beds and a probable modern analogue. In: Cobb, J.C., Cecil, C.B. (Eds.), Modern and Ancient Coal-Forming Environments. Geological Society of America Special Paper, vol. 286, pp. 119 – 138. Ferm, J.C., 1963. Coal beds of the Princess Reserve District. In: Huddle, J.W., Lyons, E.J., Smith, H.L., Ferm, J.C. (Eds.), Coal Reserves of Eastern Kentucky. United States Geological Survey Bulletin, vol. 1120, pp. 32 – 55. Fonner, R.F., Reynolds, J.H., Cole, G.A., Jake, T.R., Fedorko, N., Connell, D.A., 1981. Geology along the West Virginia Portion of U.S. Route 48. West Virginia Geological Survey Publication WV-14, Morgantown, 65 pp., 2 map inserts. Frederiksen, N.O., 1961. Sporomorphae of the Brookville seam near Brookville, Pennsylvania. Unpublished MS thesis, The Pennsylvanian State University, State College, 273 pp. Gray, L.R., 1967. Palynology of four Allegheny coals, northern Appalachian coal field. Palaeontographica, Abteilung B 121, 65 – 86. Habib, D., 1965. Distribution of spore and pollen assemblages in the Lower Kittanning coal of western Pennsylvania. Unpublished PhD dissertation, The Pennsylvania State University, State College, 310 pp. Habib, D., 1966. Distribution of spore and pollen assemblages in the Lower Kittanning coal of western Pennsylvania. Palaeontology 9 (4), 629 – 666. Helfrich, C.T., 1981. Preliminary correlations of coals of the Princess Reserve District in eastern Kentucky. In: Cobb, J.C., Chesnut, Jr., D.R., Hester, N.C., Hower, J.C. (Eds.), Coal and CoalBearing Rocks of Eastern Kentucky. Field trip guidebook for the Geological Society of America Coal Division. Kentucky Geological Survey, University of Kentucky, Lexington, KY, pp. 106 – 119. Hower, J.C., Eble, C.F., Rathbone, R., 1994. Petrology and palynology of the No. 5 Block coal bed, northeastern Kentucky. International Journal of Coal Geology 25, 171 – 193. Kosanke, R.M., 1943. The characteristic plant microfossils of the Pittsburgh and Pomeroy coals of Ohio. American Midland Naturalist 29 (1), 119 – 132. Kosanke, R.M., 1950. Pennsylvanian spores of Illinois and their use in correlation. Illinois State Geological Survey Bulletin 74, 128 pp. Kosanke, R.M., 1973. Palynological studies of the coals of the Princess Reserve District in northeastern Kentucky. United States Geological Survey Professional Paper 839, 24 pp. Kosanke, R.M., 1984. Palynology of selected coal beds in the proposed Pennsylvanian System stratotype of West Virginia. United States Geological Survey Professional Paper 1318, 44 pp. Kosanke, R.M., 1988a. Palynological studies of Lower Pennsylvanian coal beds and adjacent strata of the proposed Pennsylva-
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nian System stratotype in Virginia and West Virginia. United States Geological Survey Professional Paper 1479, 17 pp., 2 plates. Kosanke, R.M., 1988b. Palynological studies of Middle Pennsylvanian coal beds of the proposed Pennsylvanian System stratotype in West Virginia. United States Geological Survey Professional Paper 1455, 73 pp., 3 plates. Kosanke, R.M., 1988c. Palynological analyses of Upper Pennsylvanian coal beds and adjacent strata of the proposed Pennsylvanian System stratotype in West Virginia. United States Geological Survey Professional Paper 1486, 24 pp., 2 plates. Kosanke, R.M., Cecil, C.B., 1996. Late Pennsylvanian climate changes and palynomorph extinctions. Review of Paleobotany and Palynology 90, 113 – 140. Neves, R., 1958. Upper Carboniferous plant spore assemblages from the Gastrioceras subcrenatum horizon, North Staffordshire. Geological Magazine 95, 1 – 19. Owens, B., 1996. Upper Carboniferous spores and pollen. Jansonius, J.J., McGregor, D.C. (Eds.), Palynology: Principles and Applications, vol. 2. American Association of Stratigraphic Palynologists Foundation, pp. 597 – 606. Peppers, R.A., 1964. Spores in strata of Late Pennsylvanian cyclothems in the Illinois Basin. Illinois State Geological Survey Bulletin 90, 89 pp. Peppers, R.A., 1970. Correlation and palynology of coals in the Carbondale and Spoon Formations (Pennsylvanian) of the northeastern part of the Illinois Basin. Illinois State Geological Survey Bulletin 93, 173 pp. Peppers, R.A., 1979. Development of coal-forming floras during the early part of the Pennsylvanian in the Illinois Basin. In: Palmer, J.E., Dutcher, R.R. (Eds.), Depositional and Structural History of the Pennsylvanian System of the Illinois Basin. Ninth International Congress of Carboniferous Stratigraphy and Geology, Guidebook for Field Trip 9, Part Two (Invited Papers). Illinois State Geological Survey Guidebook Series, vol. 15a, pp. 8 – 14. Peppers, R.A., 1984. Comparison of miospore assemblages in the Pennsylvanian System of the Illinois Basin with those in the upper Carboniferous of western Europe. In: Sutherland, P.K., Manger, W.L. (Eds.), Compte Rendu Neuvie`me Congre`s International de Stratigraphie et de Ge`ologie du Carbonife`re. Biostratigraphy, vol. 2, pp. 483 – 502, Washington DC and Champaign-Urbana 2. Peppers, R.A., 1985. Comparison of miospore assemblages in the Pennsylvanian System of the Illinois Basin with those in the Upper Carboniferous of western Europe. In: Sutherland, P.K., Manger, W.L. (Eds.), Biostratigraphy. Compte Rendu Neuvie`me Congre`s International de Stratigraphie et de Ge`ologie du Carbonife`re, Washington D.C., Champaign-Urbana, vol. 2, pp. 483 – 502. Peppers, R.A., 1996. Palynological correlation of major Pennsylvanian (middle and upper Carboniferous) chronostratigraphic boundaries in the Illinois Basin and other coal basins. Geological Society of America Memoir 188, 111 pp. Peppers, R.A., Popp, J.T., 1979. Stratigraphy of the lower part of the Pennsylvanian System in southeastern Illinois and adjacent portions of Indiana and Kentucky. In: Palmer, J.E., Dutcher, R.R. (Eds.), Depositional and Structural History of the Pennsylvanian
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System of the Illinois Basin. Ninth International Congress of Carboniferous Stratigraphy and Geology, Guidebook for Field Trip 9, Part Two (Invited Papers). Illinois State Geological Survey Guidebook Series, vol. 15a, pp. 65 – 72. Potonie´, R., Kremp, G.O.W., 1954. Die Gattungen der pala¨ozischen Sporae Dispersae und ihre Stratigraphie. Beihefte zum Geologischen Jahrbuch 69, 111 – 194. Ravn, R.L., 1986. Palynostratigraphy of the Lower and Middle Pennsylvanian coals of Iowa, Iowa Geological Survey, Technical Paper 7, 245 pp., 40 plates. Ravn, R.L., Butterworth, M.A., Phillips, T.L., Peppers, R.A., 1986. Proposed synonymy of Granasporites Alpern 1959 emend. And Cappasporites Urban emend. Chadwick 1983, miospore genera from the Carboniferous of Europe and North America. Pollen et Spores 38, 421 – 433. Rice, C.L., Hiett, J.K., 1994. Correlation of coal beds, coal zones, and key stratigraphic units in the Pennsylvanian rocks of eastern Kentucky. United States Geological Survey Miscellaneous Field Study 2275, 1 Plate. Rice, C.L., Martino, R.L., Slucher, E.L., 1992. Regional aspects of Pottsville and Allegheny Stratigraphy and Depositional Environments, Ohio and Kentucky. Field Trip Guidebook for the Annual Meeting of the Geological Society of America, Cincinnati, Ohio, October 29 – 29, 1992, United States Geological Survey Open File Report 92-558, 67 pp. Rice, C.L., Kosanke, R.M., Henry, T.W., 1994. Revision of nomenclature and correlations of some Middle Pennsylvanian units in the northwestern part of the Appalachian Basin, Kentucky, Ohio, and West Virginia. In: Rice, C.L. (Ed.), Elements of Pennsylvanian Stratigraphy. Geological Society of America Special Paper, vol. 294, pp. 7 – 26. Riffelmacher, W.E., 1952. Microspores of the Lower Kittanning coal in its type area. Unpublished MS Thesis, The Pennsylvania State University, 101 pp. Schemel, M.P., 1951. Small spores of the Mystic coal of Iowa. American Midland Naturalist 46, 743 – 750. Schemel, M.P., 1957. Small spore assemblages of mid-Pennsylva-
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Palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin Cortland F. Eble * Kentucky Geological Survey, Energy and Industrial Minerals Section, University of Kentucky, 288 Mining and Minerals Building, Lexington, KY 40506-0107, USA Received 21 November 2001; accepted 29 April 2002
Abstract Fossil spores and pollen have long been recognized as valuable tools for identifying and correlating coal beds. This paper describes the palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin with emphasis on forms that assist both intra- and interbasinal coal bed correlation. Stratigraphically important palynomorphs that originate in late Middle Pennsylvanian strata include Torispora securis, Murospora kosankei, Triquitrites minutus, Cadiospora magna, Mooreisporites inusitatus, and Schopfites dimorphus. Taxa that terminate in the late Middle Pennsylvanian include Radiizonates difformis, Densosporites annulatus, Dictyotriletes bireticulatus, Vestispora magna, and Savitrisporites nux. Species of Lycospora, Cirratriradites, Vestispora, and Thymospora, as well as Granasporites medius, Triquitrites sculptilis, and T. securis end their respective ranges slightly higher, in earliest Late Pennsylvanian age strata. Late Middle Pennsylvanian and earliest Late Pennsylvanian strata in the Appalachian Basin correlate with the Radiizonates difformis (RD), Mooreisporites inusitatus (MI), Schopfites colchesterensis – S. dimorphus (CP), and Lycospora granulata – Granasporites medius (GM) spore assemblage zones of the Eastern Interior, or Illinois Basin. In the Western Interior Basin, these strata correlate with the middle-upper portion of the Torispora securis – Laevigatosporites globosus (SG) and lower half of the Thymospora pseudothiessenii – Schopfites dimorphus (PD) assemblage zones. In western Europe, late Middle Pennsylvanian and earliest Late Pennsylvanian strata correlate with the middle-upper portion of the Torispora securis – T. laevigata (SL) and the middle part of the Thymospora obscura – T. thiessenii (OT) spore assemblage zones. Allegheny Formation coal beds also correlate with the Torispora securis (X) and Thymospora obscura (XI) spore assemblages, which were developed for coal beds in Great Britain. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Pennsylvanian; Palynology; Appalachian Basin; Westphalian; Desmoinesian
1. Introduction Coal palynology has long been of value in helping to identify and correlate Pennsylvanian-age coal-bear-
*
Tel.: +1-606-257-5500; fax: +1-606-257-1147. E-mail address: [email protected] (C.F. Eble).
ing strata. This technique primarily relies on the identification of stratigraphically constrained palynotaxa, although some beds can be identified and separated from adjacent beds, based on the relative abundance of otherwise common, long-ranging forms. Coal palynology is also a useful tool in reconstructing the ancient floras that inhabited late Carboniferous mires (Kosanke, 1943, 1950, 1973, 1988a,b,c;
0166-5162/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 6 - 5 1 6 2 ( 0 2 ) 0 0 11 4 - 3
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C.F. Eble / International Journal of Coal Geology 50 (2002) 73–88
Peppers, 1964, 1970, 1979, 1984, 1996; Peppers and Popp, 1979; Eble, 1988, 1996a,b; Eble and Grady, 1990, 1993; Willard, 1994). This paper focuses on the palynology of late Middle Pennsylvanian coal beds from the Appalachian Basin and discusses the criteria used to identify and correlate individual coal beds and coal zones, both on an intra- and interbasinal scale. Palynology is an especially important correlation tool in the Appalachian Basin, which is dominated by lithologies of terrestrial origin, and as such, has limited potential for marine macro- and microfaunal bed identification and correlation.
2. Previous work The earliest attempts to use fossil spores and pollen as a correlation tool in the Appalachian Basin were done with coal thin sections by Rheinhardt Thiessen and his co-workers at the United States Bureau of Mines (e.g., Thiessen and Staud, 1923; Thiessen and Wilson, 1924). Early palynological studies of Appalachian coals that utilized the maceration method include those by Kosanke (1943), who reported on the palynology of the Pomeroy (Redstone) and Pittsburgh coals of eastern Ohio; Cross (1947) and Cross
Fig. 1. Coal bed stratigraphy of the study interval. Note that Formation and Group nomenclature is not uniform. For example, in northern West Virginia, western Pennsylvania, and Ohio, late Middle Pennsylvanian-age coal beds are assigned to the Allegheny Formation, while older coal beds (Mercers, Quakertown, and Vandusen) are assigned to the Pottsville Group. Late Pennsylvanian coal beds in this area (Bakerstown, Brush Creek, and Mahoning) are assigned to the Glenshaw Formation of the Conemaugh Group. In contrast, late Middle Pennsylvanian coal beds in southern West Virginia are assigned to the Charleston Sandstone, with older coals (Stockton, Coalburg, and Winifrede) being assigned to the Kanawha Formation. Late Pennsylvanian strata in this area are assigned to the Conemaugh Formation. In northeastern Kentucky, late Middle Pennsylvanian coal beds are assigned to the Princess Formation. Older coals (Princess Nos. 3 and 4) are assigned to the Four Corners Formation, and younger Late Pennsylvanian coal beds (Brush Creek, Bakerstown) are assigned to the Conemaugh Formation.
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and Schemel (1952), who described the characteristic small spore floras of eastern Kentucky and southern West Virginia coals; and Cropp (1963) who documented the palynofloras of several Lower and Middle Pennsylvanian Tennessee coal beds. Several studies have focused on the palynology of late Middle Pennsylvanian (Allegheny Formation and equivalent, Fig. 1) coals, and thus are of particular value in the present work. These include: Denton (1957), who correlated Lower Allegheny Formation coal beds in Columbiana County, Ohio with adjacent areas; Schemel (1957), who characterized the small spore assemblages of some Middle Pennsylvanian-age coals in West Virginia and surrounding areas; and Frederiksen (1961), who documented the palynology of the Brookville coal in western Pennsylvania. Studies of the Lower Kittanning coal bed include those by Riffelmacher (1952) and Habib (1965, 1966) in western Pennsylvania, and Gray (1967) in east central
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Ohio. Kosanke (1973, 1984, 1988a,b,c) reported on the palynology of late Middle Pennsylvanian coals from the Princess Coal Reserve District in northeastern Kentucky, and from the proposed Pennsylvanian System stratotype area in southern West Virginia. Helfrich (1981) studied some late Middle Pennsylvanian coals from drill cores in northeastern Kentucky, and made some preliminary correlations using palynomorphs. More recently, Kosanke and Cecil (1996) have discussed the palynofloral changes that occur across the late Middle to early Late Pennsylvanian transition, and its significance in terms of climate change in the Appalachian Basin.
3. Materials and methods Samples of coal were collected from three sections that expose late Middle Pennsylvanian strata. They
Fig. 2. Location map for the sections used in this study. Refer to Fig. 1 for the stratigraphic position of coal beds sampled in each section. The stippled area is the approximate outline of coal-bearing strata of Pennsylvanian age in the Appalachian Basin.
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are: (1) the Chestnut Ridge/Interstate 68 section near Morgantown, West Virginia, (2) the Powell Mountain section at Birch River, West Virginia, and (3) the Interstate 64 section in northeastern Kentucky (Fig. 2). A list of the samples used in this study is presented in Appendix A. All samples were first mechanically crushed to a maximum particle size of 1 mm and riffled to obtain a representative subsplit of approximately 50 g. A total of 5 g of coal were oxidized with Schulze’s Solution (concentrated nitric acid saturated with potassium chlorate), digested with a 5% solution of potassium hydroxide, screened with a 250-mm mesh screen to remove coarse debris, and concentrated with zinc chloride (specific gravity 1.9). Residues were dehydrated with cellosolve (2-ethoxyethanol), and mounted on 75 25 mm microscope slides (30 22 mm cover glasses) with Canada balsam. Counts of 250 palynomorphs/sample were employed to determine the relative abundance of spore taxa, with the remainder of the slide being scanned with a low-power objective to record any forms not encountered during the statistical counts. Extra coal, maceration residues, and slides generated from this study are housed at the Kentucky Geological Survey in Lexington, KY.
4. Results 4.1. Chestnut Ridge section The late Middle Pennsylvanian Allegheny Formation is exposed in northern West Virginia where Interstate 68 transects the Chestnut Ridge anticline (between mile posts 10 and 16; see Fonner et al., 1981). In stratigraphically descending order, the coals that were sampled are the Upper Freeport, Lower Freeport, Upper, Middle, and Lower Kittanning, and an unnamed coal below the Lower Kittanning (Fig. 3). All of the Allegheny Formation coals in this section are co-dominated by tree fern spores and Lycospora, the spore produced by many of the large lycopod trees which were a conspicuous element in Early and Middle Pennsylvanian mires. The most common species of Lycospora are Lycospora granulata and L. pusilla. Tree fern spore diversity was at its apex during the late Middle Pennsylvanian, with several species being recognized. These include Punctatisporites minutus,
Punctatosporites minutus, Punctatosporites rotundus, Laevigatosporites minimus, Thymospora pseudothiessenii, Laevigatosporites globosus, Punctatosporites granifer, and Torispora securis. Stratigraphically important taxa in this section include the occurrence of Murospora kosankei, Mooreisporites inusitatus, Triquitrites minutus, T. securis, and T. pseudothiessenii in all of the Allegheny Formation coal beds in the section. Schopfites dimorphus is restricted to the Lower, Middle, and Upper Kittanning coal beds, and the Middle Kittanning coal marks the last occurrence of Densosporites. The Upper Freeport coal bed is the last coal in the section that contains Lycospora, Granasporites medius, Thymospora pseudothiessenii, Triquitrites sculptilis, Torispora securis, Murospora kosankei, Mooreisporites inusitatus, Cirratriradites, and Vestispora. Elsewhere in the Appalachian Basin, these taxa terminate in the overlying Mahoning coal, which is the next coal in stratigraphic sequence above the Upper Freeport coal. The Upper Freeport and Mahoning coals have essentially identical palynofloras (Schemel, 1957; DiMichele et al., 1996; Peppers, 1996). The Chestnut Ridge section occurs in an area where the interval between the Lower Kittanning coal and the top of the underlying Pottsville Group is quite thin ( < 15 m). This implies that the structural activity associated with the Chestnut Ridge anticline was penecontemporaneous with deposition of Allegheny sediments. However, in other areas of northern West Virginia, northeastern Ohio, and western Pennsylvania, this interval is much thicker (>75 m) and includes additional coal beds not present in the Chestnut Ridge section. Analyses of these coals (Schemel, 1957; Denton, 1957; Frederiksen, 1961; Peppers, 1996) indicate that Thymospora pseudothiessenii, Mooreisporites inusitatus, and Triquitrites minutus all extend down to the level of the Upper Mercer coal bed (Fig. 1). In addition, Torispora securis was found in the underlying Middle Mercer (Peppers, 1996) and Quakertown (Eble, unpublished data) coal beds, the latter being sampled from its ‘‘type’’ locality on Quakertown run near Lowellville, Ohio. 4.2. Birch River section Strata assigned to the Charleston Sandstone are exposed near the town of Birch River in southern
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Fig. 3. Distribution of numerically significant miospore taxa, grouped together according to affinity, in Allegheny Formation coal beds collected from the Chestnut Ridge section in northern West Virginia.
West Virginia where US Route 19 transects Powell Mountain. The name Charleston Sandstone was proposed by Campbell and Mendenhall (1896) for strata bounded by the Kanawha Black Flint at the base and red and green shales considered to mark the base of the Conemaugh Formation at the top. The unit is bestdeveloped in the immediate vicinity of Charleston, West Virginia, and is composed of approximately 70% or more sandstone that occurs in thick, coalescing sequences (Arndt, 1979). In stratigraphically descending order, the coal beds that were sampled are the No. 7 Block, No. 6 Block, No. 5 Block, Little No. 5 Block, and Stockton ‘‘A’’. In addition, three additional coals, the Stockton, Coalburg, and Winifrede, were sampled from the underlying Kanawha Formation (Fig. 4).
All of the sampled coals are dominated, or codominated, by Lycospora and tree fern spores. The Winifrede, Coalburg, and Stockton contain similar assemblages with the notable presence of Radiizonates difformis. Coal beds older than the Winifrede do not contain R. difformis (Kosanke, 1984, 1988a,b; Eble, 1996a,b). The Stockton coal also marks the first appearance of Torispora securis, which occurs in much higher percentages in the overlying Stockton ‘‘A’’ coal. The Little No. 5 Block coal occurs in two benches in the Birch River section and marks the first occurrence of Murospora kosankei, Triquitrites minutus, Mooreisporites inusitatus, and Cadiospora magna in the Birch River section. The overlying No. 5 Block coal, which also occurs in two splits (called Upper and
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Fig. 4. Distribution of numerically significant miospore taxa, grouped together according to affinity, in the Birch River section in southern West Virginia.
Lower No. 5 Block), is an important horizon as it marks the last occurrence of Radiizonates difformis, Densosporites annulatus, Savitrisporites nux, Vestispora magna, and Dictyotriletes bireticulatus. The Upper No. 5 Block coal also contains the first record of Thymospora pseudothiessenii and T. obscura, which helps to differentiate the two benches. The No. 6 Block coal bed is the only coal in the Birch River section that contains Schopfites dimorphus. Although the No. 5 Block coal has been historically correlated with the Lower Kittanning coal of northern West Virginia and western Pennsylvania (e.g., Wanless, 1939), spore assemblages from the Lower Kittanning more closely resemble those from the No. 6 Block coal (Kosanke, 1984). The highest coal in the section, the No. 7 Block coal bed, contains a miospore assemblage similar to those obtained from
the Upper and Lower Freeport coals in the Chestnut Ridge section. Of particular note are relatively high percentages (8%) of Triquitrites in the No. 7 Block coal. 4.3. Interstate 64 section Late Middle Pennsylvanian strata assigned to the Princess Formation are exposed along a series of roadcuts between mileposts 173 and 191 on Interstate 64 in northeastern Kentucky (Fig. 2) (Chesnut, 1992). Sampled coal beds include the Princess No. 5 through Princess No. 9 coal beds (Fig. 5). Two stratigraphically older coals assigned to the Four Corners Formation, the Princess No. 3 and Princess No. 4, were also sampled and analyzed (Fig. 6). Collectively, the Princess No. 3 through Princess No. 9 coal beds all
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Fig. 5. Distribution of numerically significant miospore taxa, grouped together according to affinity, from coals in the Princess No. 5 through Brush Creek coal beds in the Interstate 64 section in northeastern Kentucky.
contain miospore assemblages co-dominated by Lycospora and tree fern spores. Stratigraphically important taxa in the Princess No. 3 coal bed include Radiizonates difformis, Laevigatosporites globosus, and Triquitrites sculptilis. The Princess No. 3 coal bed marks the beginning of the range zone of R. difformis in northeastern Kentucky, whereas the latter two forms both originate in slightly older coals. The distinctive monolete spore Torispora securis is first seen in the overlying Princess No. 4 coal bed. The Princess No. 5 coal marks the last appearance of Radiizonates difformis. As such, the range of R. difformis in northeastern Kentucky is known to extend from the Princess No. 3 coal to Princess No. 5 coal. A prior study of the Richardson coal in southeastern Kentucky (Hower et al., 1994), which is correlative with the Princess No. 5 (Rice and Hiett, 1994), also
recorded the presence of Radiizonates difformis. Other palynomorphs that terminate in the Princess No. 5 coal are Densosporites annulatus, Vestispora magna, Savitrisporites nux, and Dictyotriletes bireticulatus. The Princess No. 5 coal also marks the first appearance of Triquitrites minutus, Murospora kosankei, Mooreisporites inusitatus, and (sporadic) Cadiospora magna. The Princess No. 5 is overlain by two thin, laterally discontinuous coals, the Princess No. 5a and No. 5b coal beds (Figs. 1 and 5). In places, these two coals are bounded by the Kilgore Flint Member (Rice et al., 1994), which underlies the Princess No. 5a coal, and the Obryan limestone above the 5b coal (Rice et al., 1992), which may be equivalent with the Vanport Limestone of south central Ohio (Ferm, 1963). The Princess No. 5a coal bed contains the first occurrences of Thymospora pseudothiessenii, T. obscura, and
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Fig. 6. Distribution of numerically significant miospore taxa, grouped together according to affinity, from the Princess No. 3 and No. 4 coal beds in the Interstate 64 section in northeastern Kentucky.
Schopfites carbondalensis. A thick, well-developed paleosol separates the Princess No. 5b from the Princess No. 6. This paleosol, known locally as the Hitchens clay bed, is one of the most laterally extensive claystones in the area. Palynologically, the Princess No. 6 coal bed marks the first occurrence of Schopfites dimorphus. S. dimorphus has a very limited range in northeastern Kentucky, occurring in only the Princess No. 6 and No. 7 coal beds (Kosanke, 1973). As such, it is an extremely useful palynomorph for bed identification and correlation. The Princess No. 7 coal bed also marks the last sporadic occurrence of Densosporites. The overlying Princess No. 8 and No. 9 coal beds are palynologically indistinguishable, with the Princess No. 8 coal marking the last occurrences of Murospora kosankei and Mooreisporites inusitatus. Likewise, the overlying Princess No. 9 coal bed contains the last occurrences of Lycospora, Granasporites medius, Cirratriradites,
Thymospora pseudothiessenii, Torispora securis, Vestispora, and Triquitrites sculptilis in the Interstate 64 section. The next coal in stratigraphic sequence, the Brush Creek coal bed, contains a noticeably different palynoflora that is devoid of Lycospora (Fig. 5).
5. Correlation within the Appalachian Basin Wanless (1939) correlated Princess Formation coals of northeastern Kentucky with Allegheny Formation coals of eastern Ohio and western Pennsylvania as follows: Kentucky Princess Princess Princess Princess
No. No. No. No.
Ohio and Pennsylvania 9 8 7 6
Upper Freeport coal Lower Freeport coal Middle Kittanning coal Lower Kittanning coal
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Although largely based on lithostratigraphy, these correlations are supported by palynological data derived from the present investigation and also from earlier reports (Kosanke, 1973, 1984, 1988a,b). Fig. 7 shows the correlation of coal beds in the three studied sections, which is based on the ranges of certain palynotaxa. For example, Schopfites dimorphus only occurs in the Princess No. 6 and No. 7 coal beds in northeastern Kentucky, whereas in adjacent Ohio (Gray, 1967; Rice et al., 1994), Schopfites dimorphus is confined to the Lower and Middle Kittanning coal beds. In northern West Virginia and western Pennsylvania, the range of Schopfites dimorphus is in the Lower, Middle, and Upper Kittanning coal beds. Likewise, the Princess No. 7 coal represents the last occurrence of Densosporites and Schopfites dimorphus in northeastern Kentucky, whereas in Ohio
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(Denton, 1957; Gray, 1967), northern West Virginia, and western Pennsylvania, the last occurrence of Densosporites is in the Middle Kittanning coal bed. The proposed lithostratigraphic correlation of the Princess No. 8 and No. 9 coals with the Lower and Upper Freeport coals seems reasonable, as the beds are palynologically very similar. Likewise, the Brush Creek coal in Kentucky appears palynologically identical to the Brush Creek coal of northern West Virginia, Pennsylvania, and Ohio (Eble, unpublished data). Other palynological correlations are also warranted. The last occurrence of Radiizonates difformis in the Princess No. 5 coal bed of northeastern Kentucky, the Lower No. 5 Block coal of southern West Virginia, the Richardson coal of southeastern Kentucky, and the Newland coal bed in southeastern Ohio (Rice et al., 1994; Eble, unpublished data, see Fig. 1)
Fig. 7. Range chart for stratigraphically important palynomorphs identified from the Chesnut Ridge, Birch River, and Interstate 64 sections.
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indicates that these beds are correlative. Likewise, the first occurrence of Thymospora pseudothiessenii in the Princess No. 5a coal bed of northeastern Kentucky, the Upper No. 5 Block coal bed in southern West Virginia, and the Ogan coal bed of southeastern Ohio indicates that these beds are regional correlatives (Fig. 1). Correlation of this interval with more northern areas (northeastern Ohio, western Pennsylvania, northern West Virginia) is problematic as Radiizonates difformis has not been identified from coals in the lower part of the Allegheny Formation, or the upper part of the Pottsville Group in the Northern Appalachian Basin. Furthermore, Thymospora pseudothiessenii has been identified from coals in the Upper Pottsville Formation (Peppers, 1996) (Mercer coal beds, see Fig. 1), well below the level of the Lower Kittanning coal bed. This contrasts greatly with the first occurrence of Thymospora pseudothiessenii in the Central Appalachian Basin (eastern Kentucky, southeastern Ohio, and southern West Virginia), which is immediately below the Lower Kittanning coal bed (and equivalents). Collectively, these disparities make the Lower Allegheny coals in the Northern Appalachian Basin appear ‘‘younger’’ than their Central Appalachian Basin counterparts, an observation that was noted earlier by Schemel (1957). One possibility is that range zones of Thymospora pseudothiessenii and Radiizonates difformis simply differ between the two areas, and as such cannot be used to correlate coals between the two areas. Another possibility, however, is that the Lower Allegheny (pre-Lower Kittanning coal) interval in the Central Appalachian Basin is, in fact, older than the same interval in the Northern Appalachian Basin. If true, then the thick, laterally extensive paleosol beneath the Lower Kittanning coal bed (and equivalents) actually represents a substantial unconformity, a concept postulated earlier by Arkle (1974). Torispora securis is first seen in the Princess No. 4 coal bed of northeastern Kentucky and Stockton coal bed of southern West Virginia, which are considered to be correlative. The first occurrence of Torispora securis in southeastern Ohio has not been positively identified, but probably is in one of the Mercer coal beds (Fig. 1). In the Northern Appalachian Basin, Torispora securis has been identified in the Quakertown coal bed collected from its ‘‘type’’ area (Fig. 1), although it is unknown if this represents the range
base for Torispora securis. Based on the first occurrence of Radiizonates difformis, the Princess No. 3 coal bed of northeastern Kentucky is correlative with the Vandusen coal bed of southeastern Ohio (Rice et al., 1992, 1994, see Fig. 1). The Princess No. 3 coal bed is also correlated with the Coalburg coal bed of southern West Virginia. As mentioned previously, Radiizonates difformis has not been identified in Northern Appalachian Basin coal beds.
6. Comparison of spore assemblages with other areas Peppers (1984, 1996) constructed 11 miospore assemblage zones for Pennsylvanian-age coal beds in the Eastern Interior (Illinois) Basin. Likewise, Ravn (1986) palynologically subdivided Pennsylvanian-age Western Interior Basin coals in Iowa into four assemblage zones. Carboniferous coal beds in Great Britain were studied and palynologically zonated by Smith and Butterworth (1967). Likewise, Carboniferous coal beds and sediments in western Europe were palynologically zonated by Clayton et al. (1977) (Fig. 8). More recently, Owens (1996) has summarized the more important palynological events for late Carboniferous strata in the Northern Hemisphere. Collectively, these palynomorph zonations provide a convenient basis for comparing the results of the present study with other areas. The Winifrede to No. 5 Block coal interval best compares with the Radiizonates difformis (RD) and Cadiospora magna – Mooreisporites inusitatus (MI) spore assemblage zones of the Eastern Interior Basin (Peppers, 1984, 1996). In the Western Interior Basin (Ravn, 1986), this interval correlates with the middle to upper portion of the Torispora securis –Laevigatosporites globosus (SG) assemblage zone, with the break between the Torispora securis –Laevigatosporites globosus/Dictyotriletes bireticulatus (SGb) and the Torispora securis – Laevigatosporites globosus/ Murospora kosankei (SGk) assemblage subzones occurring at the level of the Little No. 5 Block coal (Fig. 8). When compared with British coal beds (Smith and Butterworth, 1967; Clayton et al., 1977; Owens, 1996), the Winifrede and Coalburg coal beds conform to the Vetispora magna (IX) spore assemblage, while the Stockton to No. 5 Block coal interval
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Fig. 8. Correlation chart for the Appalachian, Eastern Interior, and Western Interior Basins using published miospore assemblage zones. Western Interior Basin assemblage zones are from Ravn (1986), while Eastern Interior Basin Assemblage zones are from Peppers (1984, 1996). Miospore assemblage zones for British coal beds are from Smith and Butterworth (1967), and the assemblages for western Europe are from Clayton et al. (1977). Range zone acronyms (e.g., OT and SL) are explained in the text.
correlates with the overlying Torispora securis (X) assemblage zone (Smith and Butterworth, 1967). The Winifrede to No. 5 Block coal interval also correlates with the Torispora securis– Torispora laevigata (SL) spore assemblage zone of western Europe (Clayton et al., 1977) (Fig. 8). The next interval in vertical succession, the Kittanning coal bed (and equivalents) interval, is palynologically well constrained. The Kittanning coal interval correlates with Schopfites colchesterensis – S. dimorphus (CP) spore assemblage zone of the Eastern Interior Basin (Peppers, 1984, 1996), the Thymospora pseudothiessenii –Schopfites dimorphus/ Densosporites triangularis (PDt) assemblage subzone of the Western Interior Basin (Ravn, 1986), and the lower part of the Thymospora obscura –T. thiessenii
(OT) spore assemblage zone of western Europe (Clayton et al., 1977) (Fig. 8). The Kittanning coal interval also correlates with the Thymospora obscura (XI) assemblage zone of Smith and Butterworth (1967) (Fig. 8). The Lower Freeport, Upper Freeport and Mahoning coal beds are the last coals in the Appalachian Basin that contain Lycospora. Several other taxa, including Granasporites medius, Thymospora pseudothiessenii, Triquitrites sculptilis, Torispora securis, Cirratriradites, and Vestispora, also end their ranges in these coals. The Lower Freeport through Mahoning coal beds best compare with the Lycospora granulata –Granasporites medius (GM) spore assemblage zone of the Eastern Interior Basin (Peppers, 1984, 1996), the Thymospora pseudothiessenii –Schopfites
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dimorphus/Triquitrites spinosus (PDs) assemblage subzone of the Western Interior Basin (Ravn, 1986), and the upper-middle portion of the Thymospora obscura– T. thiessenii spore assemblage zone of western Europe (Clayton et al., 1977). The Lower Freeport through Mahoning coal bed interval also correlates with the Thymospora obscura (XI) assemblage zone of Smith and Butterworth (1967) (Fig. 8). The stratigraphically youngest coals examined in this study, the Brush Creek and Bakerstown, contain palynofloras that correlate with the Punctatisporites minutus – P. obliquus (MO) miospore assemblage zone of the Eastern Interior Basin (Peppers, 1985; Peppers, 1996) and the upper part of the Thymospora obscura – T. thiessenii spore assemblage zone of western Europe (Clayton et al., 1977). No equivalent assemblages have been documented from the Western Interior Basin (Ravn, 1986) or from the coal fields of Great Britain (Smith and Butterworth, 1967).
7. Summary Palynomorphs are an important tool for identification, and correlation, of late Middle Pennsylvanian coal-bearing strata in the Appalachian Basin. Stratigraphically important forms that have their origins in the lower part of the Allegheny Formation (and equivalents) include Torispora securis, Murospora kosankei, Triquitrites minutus, Cadiospora magna, Mooreisporites inusitatus, Thymospora pseudothiessenii, and Schopfites dimorphus. Forms that end their ranges in the lower to middle part of the Allegheny Formation include Radiizonites difformis, R. rotatus, Densosporites annulatus, Dictyotriletes bireticulatus, Vetispora magna, and Savitrisporites nux. Lycospora, Granasporites medius, Thymospora pseudothiessenii, Triquitrites sculptilis, Torispora securis, Cirratriradites, and Vestispora end their ranges near the top of the Allegheny Formation (Fig. 7). The recognition of these taxa helps facilitate correlation of coal beds within the central part of the Appalachian Basin, which is important because coal nomenclature in this area is inconsistent (see Fig. 1). Correlation of lower Allegheny Formation coals (i.e., below the level of the Lower Kittanning coal and equivalents) in the Central Appalachian Basin with more northern areas is uncertain mainly because of
differences in the range zones Thymospora and Radiizonates. In the Central Appalachian Basin, Thymospora pseudothiessenii is first seen just below the level of the Lower Kittanning coal, whereas to the north, it occurs throughout the Allegheny Formation, and is even seen in late Pottsville Group coals. In the Central Appalachian Basin, R. difformis occurs up to a level just below the introduction of Thymospora (e.g., Lower No. 5 Block coal), and hence persists throughout most of the lower Allegheny Formation. In more northern areas, however, Radiizonates is completely absent in Allegheny Formation coal beds. Collectively, these range disparities make the lower part of the Allegheny Formation in the Central Appalachian Basin appear ‘‘older’’ than the same interval to the north. Palynology also assists interbasinal correlation of late Middle Pennsylvanian strata. In the Illinois Basin, Allegheny Formation (and equivalent) coals best compare with the Radiizonates difformis (RD), Cadiospora magna – Mooreisporites inusitatus (MI), Schopfites colchesterensis – Thymospora pseudothiessenii (CP), and Lycospora granulata – Granasporites medius (GM) miospore assemblage zones of the Eastern Interior Basin. Allegheny Formation coals also compare with the Torispora securis – Laevigatosporites globosus (SG) and Torispora pseudothiessenii – Schopfites dimorphus (PD) miospore assemblage zones of the Western Interior Basin, and the upper portion of the Torispora securis –T. laevigata (SL) and lower two-thirds of the Thymospora obscura – T. thiessenii (OT) spore assemblage zone of western Europe (Clayton et al., 1977). When compared to British coal beds, Allegheny Formation coal beds correlate with the Vestispora magna (IX), Torispora securis (X), and Thymospora obscura (XI) miospore assemblage zones of Smith and Butterworth (1967) (Fig. 8).
Acknowledgements Bill Grady, Nick Fedorko, and Mitch Blake, all with the West Virginia Geological and Economic Survey in Morgantown, WV, are thanked for providing the author with samples from the Birch River section, and also for numerous discussions regarding Allegheny Formation/Charleston Sandstone stratigraphy.
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Don Chesnut and Steve Greb, both with the Kentucky Geological Survey in Lexington, KY, are thanked for helping with the collection of the Interstate 64 section, and also for sharing their knowledge of Pennsylvanian-age rocks in Kentucky. Thanks go to Charles Rice, retired from the United States Geological Survey, who collected and forwarded samples of the Winters, Ogan and Newland coal beds from southeastern Ohio. Likewise, Ernie Slucher, of the Ohio Geological Survey, is thanked for collecting and forwarding a sample of the Quakertown coal bed from its type location in northeastern Ohio. Last, but certainly not least, this manuscript was greatly improved by the careful and thoughtful reviews of Bill DiMichele, of the Smithsonian Institution, Andrew Scott, of Royal Holloway and Bedford College, University of London, and Jim Hower, of the Center for Applied Energy Research in Lexington, KY.
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Birch River section—Along US Route 19 from the town of Birch River to the top of Powell Mountain in Nicholas County, West Virginia. The section is in the Widen 7.5-min quadrangle. Coal beds in Fig. 4
Thickness (m) 0.07 0.63 0.41 0.08
Appendix A. List of coal samples
No. 7 Block No. 6 Block (bench 1) No. 6 Block (bench 2) Upper No. 5 Block (0.0 – 0.08 m top of bed, bench 1) Upper No. 5 Block (0.08 – 0.19 m, bench 2) Upper No. 5 Block (0.19 – 0.33 m, bench 3) Upper No. 5 Block (0.33 – 0.45 m, bench 4) Upper No. 5 Block (0.45 – 0.63 m, base of bed, bench 5) Lower No. 5 Block Little No. 5 Block (upper split) Little No. 5 Block (lower split) Stockton ‘‘A’’ (0.0 – 0.53 m, bench 1) Stockton ‘‘A’’ (0.53 – 1.63 m, bench 2) Stockton Coalburg Winifrede
Chestnut Ridge section—Between mileposts 10 and 16 on Interstate 68 in northern (Monongalia and Preston Counties) West Virginia. The section is in the Lake Lynn 7.5-min quadrangle.
Interstate 64 section—Between mileposts 173 and 191 along Interstate 64 in northeastern Kentucky. The section is in the Grayson, Rush, Bolts Fork, Ashland, and Catlettsburg 7.5-min quadrangles.
Coal beds in Fig. 3
Thickness (m)
Upper Freeport (0.0 – 0.15 m, top of bed, bench 1) Upper Freeport (0.15 – 0.45 m, bench 2) Upper Freeport (0.45 – 0.75 m, bench 3) Upper Freeport (0.75 – 1.05 m, bench 4) Upper Freeport (1.05 – 1.35 m, base of bed, bench 5) Lower Freeport (0.0 – 0.3 m, split 1, bench 1) Lower Freeport (0.3 – 0.57 m, split 1, bench 2) Lower Freeport (split 2) Lower Freeport (split 3) Lower Freeport (0.0 – 0.23 m split 4, bench 1) Lower Freeport (0.23 – 0.61 m, split 4, bench 2) Lower Freeport (0.61 – 0.91 m, split 4, bench 3) Upper Kittanning (0.18 m, split 1) Upper Kittanning (0.27 m, split 2) Middle Kittanning (split 1) Middle Kittanning (split 2) Lower Kittanning (split 1) Lower Kittanning (split 2) unnamed Allegheny Fm coal
0.15 0.3 0.3 0.3 0.3 0.3 0.27 0.43 0.18 0.23 0.38 0.3 0.18 0.27 0.3 0.15 0.3 0.17 0.33
0.11 0.14 0.12 0.18 1.52 0.37 0.29 0.53 1.1 0.83 0.85 0.44
Coal beds in Fig. 5
Thickness (m)
Brush Creek Princess No. 9 Princess No. 8 (0.0 – 0.14 m, top of bed, bench 1) Princess No. 8 (0.14 – 0.27 m, bench 2) Princess No. 8 (0.27 – 0.42 m, bench 3) Princess No. 8 (0.42 – 0.57 m, base of bed, bench 4) Princess No. 7 (0.0 – 0.15 m, top of bed, bench 1) Princess No. 7 (0.15 – 0.30 m, bench 2) Princess No. 7 (0.30 – 0.45 m, bench 3) Princess No. 7 (0.45 – 0.6 m, bench 4) Princess No. 7 (0.6 – 0.75 m, base of bed, bench 5) Princess No. 6 Princess No. 5b Princess No. 5a Princess No. 5 (split 1) Princess No. 5 (split 2) Princess No. 5 (split 3) Princess No. 5 (split 4) Princess No. 5 (split 5)
0.3 0.08 0.14 0.13 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.41 0.38 0.08 0.36 0.13 0.3 0.05 0.04
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C.F. Eble / International Journal of Coal Geology 50 (2002) 73–88
Coal beds in Fig. 6
Thickness (m)
Princess Princess Princess Princess Princess Princess Princess Princess
0.32 0.16 0.34 0.27 0.13 0.34 0.4 0.15
No. No. No. No. No. No. No. No.
4 3 3 3 3 3 3 3
Appendix B. Formal systematic nomenclature for palynomorph taxa discussed in the text Murospora kosankei Somers, 1952 Triquitrites minutus Alpern, 1958 Cadiospora magna Kosanke, 1950 Mooreisporites inusitatus (Kosanke) Neves, 1958 Schopfites dimorphus Kosanke, 1950 Radiizonates difformis (Kosanke) Staplin and Jansonius, 1964 Densosporites Berry emend. Butterworth et al., 1964 Densosporites annulatus (Loose) Schopf et al., 1944 Dictyotriletes bireticulatus (Ibrahim) Potonie´ and Kremp emend. Smith and Butterworth, 1967 Vestispora magna (Butterworth and Williams) Spode (in Smith and Butterworth, 1967) Savitrisporites nux (Butterworth and Williams) Sullivan emend. Smith and Butterworth, 1967 Lycospora Schopf, Wilson and Bentall emend. Potonie´ and Kremp, 1954 Cirratriradites Wilson and Coe, 1940 Vestispora Wilson and Hoffmeister emend. Wilson and Venkatachala, 1963 Thymospora Wilson and Venkatachala, 1963 Thymospora pseudothiessenii (Kosanke) Wilson and Venkatachala, 1963 Thymospora obscura (Kosanke) Wilson and Venkatachala, 1963 Granasporites medius Alpern emend. Ravn et al., 1986 Triquitrites sculptilis Balme emend. Smith and Butterworth, 1967 Torispora securis Balme emend. Alpern et al., 1965 Punctatisporites minutus Kosanke emend. Peppers, 1964 Punctatosporites minutus Ibrahim emend. Alpern and Doubinger, 1973 Punctatosporites rotundus Bharadwaj emend. Alpern and Doubinger, 1973 Laevigatosporites minimus (Wilson and Coe) Schopf et al., 1944 Laevigatosporites globosus Schemel, 1951 Punctatosporites granifer Potonie´ and Kremp emend. Alpern and Doubinger, 1973
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