Petrological and chemical characteristics of liptinite-rich coals from Alberta, Canada

Petrological and chemical characteristics of liptinite-rich coals from Alberta, Canada Fariborz Goodarzi and Lloyd Snowdon Institute of Sedimentary and Petroleum Geology, Geological Survey of Canada, 3303-33rd Street NW, Calgary, Alberta T2L 2A 7, Canada

Thomas Gentzis* Alberta Research Council, Coal and Hydrocarbon Processing Department, One Oil Patch Drive, Devon, Alberta TOC lEO, Canada

David Pearson David E. Pearson and Associates Ltd, 4277 Houlihan Place, Golden Head, Victoria, British Columbia V8N 3T2, Canada Received 14 September 1992; revised 4 June 1993; accepted 11 June 1993 A suite of liptinite-rich coals from the Lower Cretaceous Mannville Group in the subsurface of Alberta, Canada has been studied with respect to its organic petrology and organic geochemistry. The samples are rich in fluorescing vitrinite (perhydrous), sporinite, cutinite, exsudatinite and bituminite. Rock-Eval analysis shows that the coals are enriched in hydrogen (hydrogen index up to 320 mg HC/g TOC) and depleted in oxygen (oxygen index up to 11 mg CO2/g TOC). The value of Tmax ranges from 445 to 460°C, indicating a late catagenic level of thermal maturity (equivalent to %Ro = 1.0-1.1 ), but the vitrinite reflectance is between 0.68 and 0.81%, indicating that it is lowered by as much as 0.4%. The pyrolysis chromatograms of the coal samples are dominated by substituted benzenes (toluene and xylenes), naphthalenes, phenanthrenes, substituted phenols (cresols) and small amounts of n-alkanes in the range C20+. Gas chromatography-mass spectrometry of the steranes and terpanes indicates little or no contribution of allochthonous bitumen to the coals. In addition, the rn/z = 217 sterane traces are dominated by C29 compounds with little C27 and C28; this, along with the high terpane to sterane ratio (m/z 191 to m/z 217 = 8.8) indicates that the bitumen was generated from terrestrially derived organic matter. The bitumen in the coals has most likely been autogenerated by the coals themselves in response to thermal stress. The originally sapropelic coals were probably deposited in an anaerobic environment and were much enriched in hydrogen. This study shows that terrigenous organic matter, when associated with an anomalous liptinite content, may have the potential to generate bitumen.

Keywords: liptinite-rich coals; organic petrology; organic geochemistry; bitumen generation

The ability of coal to generate liquid hydrocarbons has been the subject of many studies (e.g. Brooks and Smith, 1967: 1969: Cooper and Murchison, 1969; Allan and Douglas, 1974: Allan, 1975; Khavari-Khorasani and Murchison, 1988). Coals are generally divided into three groups: humic, liptinite-rich humic and sapropelic. Humic coals have a liptinite content of up to 20 w~l.%, liptinite-rich humic coals up to 50 vol.% and sapropelic coals greater than 5(1 vol.% (Goodarzi and Goodbody, 1990). Liptiniterich and sapropelic coals are enriched in hydrogen and can be the source of liquid to gaseous hydrocarbons (Snowdon eta[., 1986; Fowler et al., 1991). Humic coals are formed in terrestrial depositional environments (fluviodeltaic and lacustrine) whereas liptinite-rich and sapropelic coals are generally formed in lacustrine to brackish environments (Teichm011er, 1982). The *

('orrcspondcncc to l)r T. ()cntzis

maceral composition of each of these coal groups is consistent with the environment of deposition. Humic coals are dominated by vitrinite; liptinite-rich humic coals are dominated by vitrinite and liptinite. Sapropelic coals are dominated by liptinite macerals (Moore, 1968; Stach, 1982). Sapropelic coals are hydrogen-rich due to the presence of liptinite macerals and consist of two types, namely boghead and cannel coals (Moore, 1968; Teichmiiller, 1982). They form as a result of the physical and biological degradation of peat and coal via the selective removal of humic compounds (Moore, 1968). Cannel coals consist of sporinite, whereas boghead coals are rich in alginite (e.g. Botrvococcus; Moore, 1968). Vitrinite from humic coals of subbituminous to bituminous rank is usually non-fluorescing; vitrinite of a similar rank in sapropelic coals may have some degree of fluorescence. Vitrinite is also divided into two groups, hydrous and perhydrous (Teichmtiller,

0264-8172/94/030/307-13 ~ 1994 Butterwortb-Heinemann Ltd

Marine and Petroleum Geology 1994 V o l u m e 11 N u m b e r 3

307

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al. 1982). Perhydrous vitrinite is structureless, shows a 10 (A) km reddish brown fluorescence and has a high swelling index during heating (Creaney et al., 1980; Teichmiiller and Teichmfiller, 1982). It yields high tar (bitumen) and is rich in inherent ash (Lapo, 1978). This type of Willesden Medicine vitrinite is impregnated by extractable bituminous G1r'e~e3"~ n ~/'5 River ~ ~m materials during the 'early bituminous coal stages' (Kroger, 1968). Perhydrous vitrinites are often marineLAKE influenced (e.g. the Katharina seam, West Germany; " \ Teichmfiller, 1982). They have high hydrogen and nitrogen contents and a higher volatile matter content KEY than humic coals (Teichmfiller, 1986). Teichmtitler and MAP Teichmfiller (1982) have stated that 'putrefaction (fermentation) only occurs under reducing conditions, when anaerobic bacteria consume the oxygen of organic substances, transforming them into hydrogenrich bituminous products. During coalification, weakly(B) reflecting vitrinites, containing relatively large amounts of extractable bitumen form from these products.' Thisstudy Hayes,1986 James,1985 Perhydrous Cretaceous coals have been reported from many localities - - for example, Australia (Cook, 1975; Creaney et al., 1980), Canada (Stasiuk, 1984), Germany (Kroger, 1968; Teichmi)ller, 1974), Romania, Pakistan and Japan (Teichm011er, 1974) and the former USSR (Lapo, 1979). Khavari-Khorasani (1987) found that the oil-proneness of the Waloon Glaucomttc MemOer UPPER MANNVILLE Glauconitic Sandstone coals, Surat Basin, Australia was governed not only by FORMATION L Fel(lspathtcMember the total liptinite content and the percentage of Limestone or % different liptinite macerals, but also by the fluorescing 0 "Calcareous" bioturbated mudstone member (perhydrous) nature of the vitrinite and the near cE Calcareous Very fine grained absence of inertinite. Similar conclusions have also sandstone Member Lu been made by Bertrand (1989) in a study of Jurassic medial member Bioturbated mudstone coals from the North Sea. A number of coals in cores from wells in Townships 39-4W5 and 39-5W5 in Alberta (Figure 1A), have an Cut Bank Cut Bank Cut Bank Sandstone member Member oily or greasy appearance in hand specimen and fluorescent vitrinite under microscopic examination. 2 The cores were recovered from depths ranging from DEVILLE FORMA TION 2239 to 2318 m within the Mannville Group (Figure 1B), in the vicinity of the Willesden Green and Figure I (A) Map of Alberta, Canada showing study area and Medicine River oilfields, west of Sylvan Lake (Figure drillhole location. (B) Stratigraphic column of the Lower Creta1A). Three of the samples were from less than 1.8 m ceous Mannville Group units, Alberta Plains (after Banerjee, 1990) and one sample was about 5.5 m above the top of the Glauconitic Sandstone (Figure 1B). Samples from 2315.9 to 2317 m straddle the top of the Glauconitic during the Columbian Orogeny. The palaeogeography Sandstone formation boundary at 2315.9 m. and regional stratigraphy of the Mannville Group in Hacquebard (1977) conducted an initial study on Alberta has been presented by Jackson (1985). SediMannville Group coals in Alberta. He stated that the mentological and palaeontological evidence suggests coals are thin and lie too deep to be mined. The that marine conditions prevailed during the deposition maximum reflectance (Romax) of 34 core samples is in of the strata comprising the Ostracode Zone (Figure the range 0.41-1.58, depending on the geographical 1B) (Banerjee, 1990). The boundary between the location of the samples. Nevertheless, there was an Ostracode Zone and the overlying Glauconitic Sandoverall increase in the rank of the Mannville coals in a stone is a typical progradational sequence. The westerly direction and towards the axis of the Alberta Ostracode Zone represents the offshore deposits, Syncline (Hacquebard, 1977). Osadetz et al. (1990) the Glauconitic Sandstone represents the offshorereported the reflectance of Mannville Group samples in shoreface transition, the so-called foreshore and backthe Alberta Plains and Foothills as well as Mannvilleshore, and the overlying strata, where the coal samples equivalent samples from the north-western Plains of in the present study were taken from, represent the Alberta and British Columbia (Gething Formation). coastal swamp and lagoon environments (Banerjee, 1990). Generally, reflectance was in the range 0.4%Romax to approximately 1.60%Romax, in agreement with the In a study of 28 coal samples from the upper part of data of Hacquebard (1977). the Lower Cretaceous Mannville Group in southern The Lower Cretaceous strata in the southern Alberta Alberta, Banerjee and Goodarzi (1990) used the boron Plains and Foothills constitute a north-east tapering and sulphur contents as indicators of the palaeowedge of clastic sedimentary rocks deposited in a environment of coal deposition. Boron ranged from 18 foreland basin (Porter et al., 1982) that received to 1144 ppm (23 samples had B values >100 ppm) and synorogenic detritus from the emerging Cordillera sulphur ranged from 0.56 to 23.46% (23 samples had S

a

~

308

Marine and Petroleum Geology 1994 Volume 11 Number 3

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al. Table 1 Rock-Eval, reflectance and maceral analysis of the coals Core No.

Whole-coal 1-1 Whole-coal 1-2 Whole-coal 1-3a Inertinite-rich 1-3b Vitrinite-rich 1-3c Whole-coal 2 Whole-coal 3-1a Inertinite-rich 3-1b Vitrinite-rich3-1c Whole-coal 3-2 Whole-coal 4-1a Inertinite-rich 4-1b Whole-coal 4-2a Inertinite-rich 4-2b Whole-coal 4-3a Inertinite-rich 4-3b Vitrinite-rich 4-3c Whole-coal 5-1a Inertinite-rich 5-1b Vitrinite-rich 5-1c

Depth (m)

Tmax (°C)

Sl

S2

S3

PI

$2/$3

PC

TOG

HI

OI

%Romax

% Flvit

Non-Flvit (%)

Primary liptinite*

Secondary liptinitet

2285.0 2286.0

458 455 458 456 458 456 448 449 453 447 453 452 457 456 453 451 451 457 457 457

]0.87 10.47 8.92 9.14 8.69 13.71 17.54 15.58 14.90 17.73 9.61 10.08 7.3 8.0 11.93 11.76 11.84 7.77 8.91 8.95

160.89 118.52 173.53 179.19 179.13 155.24 223.89 215.71 178.14 216.10 197.88 202.77 122.10 124.10 186.39 180.73 186.02 131.20 138.91 147.91

5.83 4.52 6.89 6.95 6.52 6.22 6.37 6.29 6.83 6.09 6.90 7.28 5.81 5.73 6.84 6.63 6.13 6.85 6,66 6.86

0.06 0.08 0.05 0.05 0.05 0.08 0.07 0.07 0.08 0.08 0.05 0.05 0.06 0.06 0.06 0.06 0.06 0.05 0.06 0.05

27.58 26,26 25.18 25.80 27.48 24.93 35.16 34.31 26.10 35,49 28.70 27.85 21,01 21.66 27.25 27.26 30.34 19.16 20.86 21.56

14.31 10.75 15.20 15.89 15.65 14.08 20.12 19.27 16.08 19.48 17.29 17.74 10.78 11.00 16.52 16.04 16.49 11.59 12.31 13.07

70.48 50.97 75.95 74.64 76.73 64.80 70.82 73.88 64.94 73.94 77.94 75.19 64.70 70.60 75,84 73.66 74.89 58.06 62.52 63.12

229 232 228 240 233 239 316 291 274 292 254 269 188 176 245 245 249 226 222 234

7.5 8.5 8.5 9 8 9 8.5 8 10 8 8.5 9 8.5 8 8 8.5 8 11 10 10

0.75 0.71 0.80 0.80 0.81 0.71 0.68 0.74 0.72 0.70 0.73 0.79 0.75 0.78 0.74 0.77 0.73 0.75 0.78 0.76

79.0 52.0 93.0 88.7 65.7 74.7 86.0 69.0 92.3 62.3 36.3 37.3 44.0 60.3 40.0 51.7 49.0 7.3 8.0 12.3

2.3 3.3 1.7 2.7 31.3 7.7 3.3 6.7 2.3 11.0 61.7 35.7 32.3 14.3 22,7 22.0 27.0 54.0 84.7 87.0

7.0 3.3 1.0 2.0 2.7 6,0 1.6 2.6 0,7 3.3 0.7 3.7 8.0 6.7 6,4 7.3 1,3 1.4 1,3 0,7

10.7 2.0 1.3 3.6 -1.3 1.3 6.0 -1.0 1.0 1.0 1.7 2.0 1.7 1.0 2.3 0.7 ---

2286.0 2319.0 2316.0 2318.0 2303.0

2300.0 2303.6

2239.0

Inertinite Mineral (%) matter (%) 1.3 18.7 3.0 3.0 0.3 5.7 3.3 9.3 0.7 14.0 -5.0 10.7 14.0 10.0 16.7 9.7 1.6 ---

-20.7 ---4.6 4.5 6.4 4.0 8.4 0.3 0.3 3.3 2.7 16.2 1.3 9.7 35.0 6.0 --

* Includes resinite, cutinite and sporinite. t Includes exsudatinite and bituminite.

values >1.0%), both indicative of coal deposition under strongly brackish water conditions, in general agreement with organic petrological and sedimentological evidence. No published age of the Glauconitic Sandstone, which underlies the coals, is known at present and an Aptian-Albian age remains uncorroborated (Banerjee, 1990). The coals studied, which belong to the Upper Mannville Subgroup of the Lower Cretaceous Mannville Group, are therefore believed to be of Albian age. The main objective of this study was to show the nature and origin of the bitumen in these coals and to examine the effect of bitumen impregnation on vitrinite reflectance. This, in turn, will help to establish if the coals were a source of hydrocarbons and to answer some basic questions about whether oil can be generated from coal.

Experimental The coal samples were selected to represent the whole coal, vitrinite-rich and inertinite-rich lithotypes (Table 1). The samples were crushed to - 2 0 mesh (850 lam), mounted in resin epoxy, ground and polished according to the method of Mackowsky (1982). Reflectance in oil (noil = 1.518 at 546 nm) was determined using a Zeiss MPM II microscope equipped with quartz halogen (12 V, 100 W) and mercury vapour (HBO) light sources and following the procedure outlined in the International Handbook of Coal Petrography (ICCP, 1971; 1975). The microscope was attached to a Zonax microcomputer. An Epiplan-'Neofluor' ×40 (NA 0.90) oil immersion objective was used for a combined total magnification of ×640. Fifty reflectance measurements (%Romax) were performed on each sample and the maceral composiTable 2 Spectral properties of liptinite macerals in the coals

Description

kma× (nm)

R/G Quotient

Resinite Exsudatinite

510 560

0.22 0.49

tion (vitrinite, liptinite and inertinite groups) was determined under ultraviolet light on 500 points, including mineral matter (Table 1), using a Swift (Model F) automatic point counter attached to a mechanical stage. The samples were photographed under fluorescent blue light (filters: excitation 450490 nm; beam splitter 510 nm; and barrier 520 nm). Spectral fluorescence measurements (Table 2) were made using the following filters: excitation, 365 nm; beam splitter, 395 nm; and barrier, 420 nm. Twenty samples were also analysed by Rock-Eval/ total organic carbon (TOC) pyrolysis (Table 3) and 12 samples of these coals rich in fluorescing vitrinite coals from five Alberta wells have been analysed using off-line flash pyrolysis-gas chromatography (GC). Compounds or compound classes eluting between toluene and C4-phenanthrene (phenanthrene with four carbon substituents, probably all methyl groups) were identified by gas chromatography-mass spectrometry (GC-MS). The flash pyrolysis was carried out using a CDS Model 120 Pyroprobe apparatus adapted as an off-line device by coupling the interface directly to a stainless-steel outlet tube immersed in liquid nitrogen. The powdered coal sample was weighed into a quartz tube and pyrolysed using a standard platinum coil probe. The temperature setting of 850°C is believed to yield an effective temperature of about 600°C at the sample under the helium carrier gas flow conditions used. The actual temperature of the pyrolysis depends to a certain extent on the position of the sample in the quartz tube and also on the position of the tube within the heating coil. A standard heating time of 20 seconds was used. Some samples were heated for 40 seconds to investigate the effect of heating time. The pyrolysis products in the liquid nitrogen trap were extracted at room temperature with n-pentane and injected directly into a capillary gas chromatograph equipped with a flame ionization detector (FID). Two samples were solvent-extracted with azeotropic chloroform-methanol (87 : 13) and fractionated using a silica gel-alumina column into saturates, aromatics, NSOs (nitrogen, oxygen, sulphur-containing compounds) and asphaltenes. The saturate fraction was analysed using a hybrid VG 70SQ gas chromatographmass spectrometer (Fowler et al., 1988) using multiple

Marine and Petroleum Geology 1994 Volume 11 Number 3

309

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al. Table 3 Fluorescing vitrinite Rock-Eval/TOC results (duplicate) Core No.*

Tm~×

$1

$2

$3

PI

$2/$3

TOC

HI

OI

1-1 1-1 1-2 1-2 1-3a 1-3a 1-3b 1-3b 1-3c 1-3c 2 2 3-1a 3-1a 3-1 b 3-1 b 3-1 c 3-1 c 3-2 3-2 4-1a 4-1 a 4-1b 4-1 b 4-2a 4-2a 4-2b 4-2b 4-3a 4-3a 4-3b 4-3b 4-3c 4-3c 5-1 a 5-1 a 5-1 b 5-1 b 5-1c 5-1 c Mean Deviation Minimum Maximum

459 457 454 455 457 460 454 459 458 459 448 445 449 448 450 449 453 453 447 447 457 456 457 457 452 453 453 453 453 453 454 449 452 451 458 457 458 457 453 456 453.8 3.9 445 460

10.40 11.34 10.37 10.58 8.97 8.88 9.07 9.21 8.57 8.81 12.98 14.44 17.25 17.84 15.25 15.92 15.00 14.80 17.14 18.33 7.85 8.14 7.35 7.30 10.39 9.80 9.80 9.43 12.14 11.72 11.42 12.10 12.03 11.66 7.59 7.96 8.83 9.00 8.80 9.10 11.19 3.14 7.30 18.33

150.81 170.96 115.28 121.76 176.32 170.74 180.74 177.64 179.28 179.98 144.73 165.74 226.27 221.56 212.54 218.88 178.88 177.40 210.71 221.48 121.25 126.85 120.75 123.26 208.62 196.92 198,40 197,35 190,71 182,06 183,21 178,24 183,38 188,66 135,74 126,85 141,16 136,66 152,23 143.58 170,91 32.47 115,28 226.27

5.51 6.15 4.33 4.70 6.93 6.85 7.03 6.86 6.60 6.44 5.96 6.48 6.27 6.47 6.10 6.48 6.66 7.00 5.89 6.29 5.71 5.74 5.66 5.96 7.45 7.11 7.00 6.79 6.96 6.72 6.60 6.66 6.10 6.16 6.85 6.85 6.66 6.66 6.86 6.86 6.41 0.63 4.33 7.45

0.06 0,06 0.08 0.08 0.05 0.05 0.05 0.05 0.05 0.05 0.08 0.08 0.07 0.07 0.07 0.07 0.08 0.08 0.08 0.08 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 0.06 0.06 0.06 0.06 0.06 0.06 0.05 0.06 0.06 0.06 0.05 0.06 0.06 0.01 0.05 0.08

27.37 27.79 26.62 25.90 25.44 24.92 25.70 25.89 27.16 27.79 24.28 25.57 36.08 34.24 34.84 33.77 26.85 25.34 35.77 35.21 21.23 22.09 21.33 20.68 28.00 27.69 28.34 29.06 27.40 27.09 27.75 26.76 30.06 30.62 19.81 18.51 21.19 20.51 22.19 20.93 26.69 4.61 18.51 36.08

72.07 68,89 50.35 51.59 77.33 74.57 74.41 74.87 75.41 78.05 61.68 67.91 71.11 70.53 73.31 74.45 64.09 65.79 73.19 74.68 69.85 71.35 65.49 63.91 76.45 73.92 80.64 75.23 76.33 75.35 74.58 72.74 74.76 75.02 58.63 57.48 61.08 63.95 63.45 62.79 69.68 7.21 50.35 80.64

209 248 228 236 228 228 242 237 237 229 234 244 318 314 289 293 279 269 287 296 173 177 184 192 272 266 246 262 249 241 245 245 245 251 231 220 231 213 239 228 244 33.3 173 3t8

7 8 8 9 8 9 9 9 8 8 9 9 8 9 9 8 10 10 8 8 8 8 8 9 9 9 8 9 9 8 8 9 8 8 11 11 10 10 10 10 8.75 0.9 7 11

* For sample depth, see Table I

ion detection for nominal masses specific to sterane and terpane compounds.

resistant constituents, such as phlobaphinitic cell excretions, are deposited and preserved as fluorescing, oval to rounded corpocollinite bodies (Plate lb).

Results and discussion

Vitrinite

Maceral composition

The main component of these coals is fluorescing vitrinite, which may form by the absorption of the biological degradation products of lipid-rich organic matter under mainly anaerobic conditions (Teichmfiller and Teichmiiller, 1982). In addition, the fluorescence of vitfinite may be caused solely by the generation of fluorophores at rank levels higher than 0.50%Ro (Lin and Davis, 1988). According to these workers, the primary fluorescence of huminite (the precursor of vitrinite) is lost as coalification increases up to the bituminous stage because an increase in aromaticity causes a greater delocalization of the ~-electrons. This is accompanied by a shift towards red in the spectral fluorescence and fluorescence quenching is enhanced by polymerization reactions and the accompanying removal of non-fluorophoric media. The development of a mobile phase in the bituminous stage of coalification results in the build-up of fluorescence intensity (secondary fluorescence of vitrinite) and a slow down in

The vitrinite maceral group is dominant (54-97%) in these coals, followed by inertinite (1-19°/,,) and liptinite (1-10%) (Table 1). Vitrinite was subdivided into two types, fluorescing (perhydrous) and nonfluorescing, with the majority being of the perhydrous type. Liptinite consists mainly of primary macerals such as sporinite, cutinite, resinite and secondary macerals, i.e. exsudatinite and bituminite (Plates 1 and 2). Exsudatinite occasionally has a granular appearance and fills cavities in inertinite fragments. Inertinite consists of semifusinite and fusinite. Some of the samples show microstratification of the liptinitic components (Plate la and lb), a characteristic feature of sapropelic coals (Moore, 1968). In contrast with true sapropelic muds, where all organic structures are destroyed by putrefaction, the coals of this study clearly show a cell structure (Plate lc) and the liptinitic and other plant remains are well preserved. The most 310

Marine and Petroleum Geology 1994 Volume 11 Number 3

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al. the spectral red shift (Lin et al., 1986; Lin and Davis, Teichmiiller and Teichmiiller, 1982, Goodarzi et al., 1988; Fowler et al., 1991). 1987). Some of the samples also contain a strongly Vitrinite, similar to that observed here (Plate ld, le fluorescing desmocollinite groundmass (Plate la), and lf) is typical of sapropelic coals, perhydrous coals typical of sapropelic coals (Creaney et al., 1980; and oil shales (Moore, 1968; Creaney et al., 1980; Teichm~iller, 1982).

..............q

i~~ii~~!iiTi~~!~:~' ! !7~'~!'~~iliTl!~!i~~iii~!i!!~'!!!~ii~!i~!i?iii!~!i!!?i~ii~i~:~~¸ i~ii!!?~!!~! !il ¸¸¸i ~!!~~ i! ............

~i~i{~ii~!ii!~i~!i!ii!(!~~ii~!~ii~~iil~i!~i!!~ii i~iii(~~~i~i~ii ~i~~i~~!~ ~i ~ i ;i ~ 0

:: |O0

:

Plate 1 All p h o t o m i c r o g r a p h s taken under fluorescence, water immersion. Filters: excitation, 490 rim; beam splitter, 510 nm; barrier,

520 nm. The long axis of each p h o t o m i c r o g r a p h is 250 t~m. (a) Sporinite (SP), cutinite (CU) and inertodetrinite (In) in a strongly fluorescing vitrinitic matrix (desmocollinite). Note the microstratification of the coal and the presence of clasts (C). (b) Thin-walled cutinite (CU) and w e a k l y fluorescing corpocollinite bodies (CO) in a fluorescing vitrinitic groundmass. (c) W o o d y cell structure (CS) clearly visible within strongly fluorescing vitrinite. (d) Corpocollinite bodies (CO) and fluorescing vitrinite. Note the presence of oil blobs (O) exuding from the cracks. (e) Concentration of fluorescing corpocollinite bodies (CO) associated with fluorescing vitrinite. (f) Granular exsudatinite (EX) filling cavities in an area of weakly to strongly fluorescing vitrinite. Inertinite is present at the top of the photomicrograph

Marine and Petroleum Geology 1994 Volume 11 Number 3

311

Characteristics o f Canadian liptinite-rich coals: F. Goodarzi et al.

~ L

L

Plate 2 Conditions as in Plate 1. (a) An oval body, possibly resinite (R), which appears to have been degraded. (b) A highly fluorescing algal body (A), non-fluorescing inertinite (IN) embedded in a fluorescing matrix (FM). (c) Granular exsudatinite (EX) filling all cavities in inertinite. (d) Similar to (c). Note the highly fluorescing liptodetrinite and vitrinite in the background

The expulsion of bitumen from the vitrinitic matrix is evident by the presence of a low fluorescence intensity near cracks and fissures, which represent localized zones of flux where the bitumen has moved out of the vitrinite, resulting in the suppression of fluorescence due to bitumen depletion (Plate ld, le and 1~.

Exsudatinite Petroleum source rocks, oil shales and coals rich in liptinite macerals (i.e. cannel and boghead coals) produce a secondary maceral called secondary resinite (Murchison, 1976) or exsudatinite (Teichmfiller, 1982). Exsudatinite forms from the liptinite-rich component of organic matter due to maturation/coalification (Shibaoka, 1978; Teichmtiller, 1982). According to Mukhopadhyay and Gormly (1984), exsudatinite is a heavy petroleum and represents mobile hydrocarbons soluble in immersion oil. Exsudatinite may also form as a result of heat generated from the burning of coal seams (Goodarzi, 1987). The generation of hydrocarbons from the coals is evident from the formation of exsudatinite (secondary resinite; Jones and Murchison, 1963) from the coal macerals (Teichmiiller, 1974; Murchison, 1976). Teichmfiller (1974) has correlated the formation of :312

Marine and Petroleum

Geology

1994 V o l u m e

exsudatinite with the beginning of oil generation in source rocks. However, the autogeneration of liquid hydrocarbons from coal seams has not been documented in detail (Murchison, 1987). The coal macerals resinite, sporinite, cutinite and suberinite may generate exsudatinite under certain conditions (KhavariKhorasani, 1987; Khavari-Khorasani and Murchison, 1988). In this suite of samples two types of exsudatinite were observed. One is present as crack- and cavityfilling (Plate 2c and 2d) and appears to have formed earlier than the second type, which is still mobile (oil expulsion; Teichmfiller and Durand, 1983) in liquid form, and oozing out of cracks (Plate ld). The evidence for the earlier formation of exsudatinite (type A) is its leaching by the liquid-type exsudatinite (type B). Leaching is evident from the formation of a granular morphology in the cavity-filling type A exsudatinite which fills the cells of inertinite. The leaching of resinite and/or exsudatinite has been reported by Goodarzi (1987) in a burning coal seam from Coalspur, Alberta. At Coalspur, exsudatinite was found in cavities and cracks of coal macerals and in many instances showed a granular appearance. Different types of exsudatinite have also been observed in the oil shales of the Emma Fiord Formation, Arctic Canada (Goodarzi et al., 11 N u m b e r 3

Characteristics of Canadian liptinite-rich coals." F. Goodarzi et al. indices (O1) are uniformly low (7-11 mg CO2/g TOC). The production index [PI = $1/($1 + $2)] values are 1.0 also low (0.05-0.08). S2/$3 ratios fall into the range 20-40. The Tm,x values obtained from Rock-Eval pyrolysis are consistent (447-458°C), with a mean value of 454°C and a standard deviation of 4°C, which is e o D 0.8 only slightly higher than the 3°C considered to be the mn • oo -o o Qo • D accuracy threshold due to variations in the instrument 0 0 • 0 program and sample size (Peters, 1986). • • m c The relationship between Tm,x and %Ro for coals 0.6 laiD analysed by Teichmtiller and Durand (1983) and for the Mannville coals is shown in Figure 3. The Mannville # # coals are grouped together showing a higher Tmax than 0.4 the coals with similar Ro values in the Teichmiiller and Durand (1983) study. For example, at 0.70-0.80%Ro, Trnax is 447-456°C for the Mannville coals and 434-443°C for the coals in the Teichmfiller and Durand 0.2 (1983) study. The level of thermal maturity indicated by T.... (447-458°C) is near the end of the 'oil window', 5 10 1'5 2'0 S l (free hydrocarbon) approximately equivalent to a vitrinite reflectance of 1.0-1.1%Ro. The TOC values (on a dry, but not Figure 2 Relationship between vitrinite reflectance and ash-free basis) range up to about 80%, also suggesting average of two Rock-Eval Sl (free hydrocarbon) analyses, a similar level of thermal maturity. However, the (in) TeichmLiller and Durand (1983); (©) this study, whole coal; (0) vitrinite-rich; ([3) inertinite-rich coal measured reflectance values of the present suite of samples (0.68-0.81%Ro ) (Table 1), as well as the 1987), each type having its own fluorescence properreflectance values of nearby coals (0.50-0.90% Romax), ties, such as kmax (wavelength of maximum intensity) determined by Pearson in an earlier study, indicate and R/G (red/green) quotient (the relative intensity at an early to mid-catagenetic stage. This discrepancy 650 nm/500 nm). Vitrinite reflectance in the coals between vitrinite reflectance indicated by T,..... and the studied has been significantly lowered (possibly as reflectance measured optically is most likely to be due much as 0.4%) and the presence of exsudatinite either to suppression of vitrinite reflectance. Suppression in filling cracks in vitrinite fragments or found in inertinite reflectance has been known for many years (Hutton and cell lumens indicates that the expulsion of liquid Cook, 1980; Price and Barker, 1985) and is believed hydrocarbons from other coal macerals has taken to be caused by the adsorption of lipoidal substances by place. The spectral fluorescence properties of resinite the vitrinite matrix. A similar effect can also be and granular exsudatinite in this suite of coals is given observed in samples rich in liptinite macerals, such as in Table 2. Unfortunately, no measurements could be sapropelic coals and oil shales (Hutton and Cook, 1980; taken from sporinite and cutinite due to their size and, Kalkreuth, 1982; Kalkreuth and Macauley, 1987). as a result, no conclusion can be drawn as to the relaSimilar observations were made by Snowdon et al. tionship between vitrinite reflectance and fluorescence for these samples. There is a slight variation in %Romax and $1 (free hydrocarbons; Teichmfiller and Durand, 1983) for the inertinite-rich coal lithotype compared with the 1.0 vitrinite-rich and/or whole coal (Table 1; Figure 2). The inertinite-rich lithology shows higher %Romax and $1 values than the whole coal and vitrinite-rich coal lithotypes (Figure 2); also, the content of inertinite in 0.8 z~ & inertinite-rich lithotypes compared with vitrinite-rich zx o lithotypes is not high, and does not exceed 14%. ._e Apparently, the available cavities in inertinite macerals ¢ facilitated the migration of hydrocarbons from the coal ¢ 0.6 matrix (vitrinite) and have allowed the hydrocarbons to seep into the available free space, resulting in the accumulation of exsudatinite (Plate 2c and 2d). There is 0.4 no direct relationship between the slight increase in S1 % and the increase in the exsudatinite content (Table 1), as might be expected. However, there is a possible correlation between the inertinite content and $1 I. 1

....

(Figure 2).

0.2

370

R o c k - Eval pyrolysis

390

430

4;0

450

470

Tmax °C

The Rock-Eval/TOC results (Table 3) are consistent for most parameters. The hydrogen indices (HI) range from 173 to 318 mg HC/g TOC, whereas the oxygen

Figure 3 Relationship between vitrinite reflectance and Trnax (average of two runs) for coals. (A) Present results; (0) exsudatinite; oil expulsion; fluorescent vitrinite

Marine and Petroleum Geology 1994 Volume 11 Number 3

313

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al. (1986) on a suite of Jurassic to Lower Cretaceous coals from British Columbia. These coals, referred to as 'needle' coals, are rich in liptinite, particularly resinite, cutinite, sporinite and bituminite, which is formed from the bacterial alteration of plant lipids and other liptinites. Alternatively, the abnormally high HI values of the coals indicate initial deposition of the organic matter in a hydrogen-rich environment where anaerobic conditions prevailed. Therefore, the lowering of vitrinite reflectance value may also be due to the hydrogen-rich nature of the vitrinite. The Rock-Eval/TOC results (Table 3; Figures 4 and 5) indicate that these samples are enriched in hydrogen and depleted in oxygen relative to most coals (see Teichmtiller and Durand, 1983). As a result, on the pseudo-Van Krevelen diagram they plot closer to the type I/type II evolution path than that of type III kerogen (Figure 4). In addition, the low OI values indicate that the coals were deposited in an environment where reducing conditions prevailed and organically bound oxygen was removed by anaerobic microbes. The low Ol values of certain coals may also be an analytical artefact because at maturity levels greater than 0.6%Ro pyrolytic oxygen may be released as carbon monoxide, which is not detected by the Rock-Eval analysis (Peters, 1986). A plot of HI versus Tm,x (Espitalie et al., 1984) is recommended to differentiate kerogen evolution pathways for type I or II organic matter and avoid any problems associated with the OI value (Peters, 1986). This plot (Figure 5) shows that the present coals have a very narrow Tm~x range (445-460°C) and plot within the mature zone of hydrocarbon generation, close to the type I/II evolution pathway.

1000 Type I

800

Type II

0 600

0

"I-

v

400

8

Type I 800

"~ o ~, z O

600

i

40O Type 11

o~ z

200

0

~e

400

~

~ 425

450

475

500

Tmax (°C)

Figure 5 Plot of Rock-Eval hydrogen index (HI) versus Tmax values with duplicate analyses plotted

The production index (PI) values are less than 0.1, which is inconsistent with thermal maturity inferred from other parameters. The low PI values indicate that volatile (S1) hydrocarbons (free hydrocarbons; Teichmiiller and Durand, 1983), which are in the range C,~-C25 are not present, suggesting that (1) there has been little or no impregnation by allochthonous material in this range and (2) indigenous hydrocarbon products were mainly
Pyrolysis-gas chromatography

"I-

200

7 O

T y p e I ll i

0

I

f

50

i

1O0

I

i

150

r

200

Oxygen index (rag C02/g Corg) Figure 4 Pseudo van Krevelen diagram of the samples studied with duplicate analyses plotted

314

Representative examples of the pyrolysis-gas chromatograms are shown in Figure 6 with peak identifications based on the mass spectrometric molecular ion weight and electron impact fragmentation pattern. Figure 7 shows GC results for samples which were analysed using a range of analytical conditions to test for the reproducibility of the results. The amount of toluene in the samples is highly variable and this is possibly due to slight variations in the precise pyrolysis conditions. Thus the chromatograms in Figure 7 have been plotted to exclude toluene and are all normalized to the largest peak in the plotted range.

Marine and Petroleum Geology 1994 Volume 11 Number 3

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al.

ee'1T (e)

c

(b) 6724 r

, CIC

CIN CIN O

5057

C CIC

i

C2N C3Nc4N

J~J

C4N

xCi

.[p ClP

5059

10

15

20

25

30

35

40

45

50

10

5

15

20

Time (rain.)

25

30

35

40

45

50

35

40

45

50

Time (rain.)

(d)

(c) 7779"

10587 C3N C ClC ClN

(J

C3P

5041-

10

15

i

P CIP

5069

20

25

30

35

40

45

50

5

10

15

20

25

30

Time (rain.)

Time (min.)

(e)

84141

X ClN

o

°

J

CIC C2N

i C2T

C4N

I

C3N Ip

ClP

5070

5

10

15

20

25

30

21

35

25

40

45

50

Time (min.)

Figure 6 Representative gas chromatograms of n-pentane extracted pyrolysis products for fluorescing vitrinite samples. T = toluene; X = xylenes; C = cresols; N = naphthalenes; P = phenanthrenes; C1-C4 indicates the number of carbons attached to the ring system, probably as methyl groups. For example, C3N represents trimethylnaphthalene and C1C is a methyl cresol (or dimethyl phenol). Normal alkanes are indicated by their integer carbon number. (a) 14-21-39-5W5, 2285 m; (b) 14-21-39-5W5, 2286 m; (c) 16-16-39-5W5, 2300 m; (d) 16-16-39-5W5, 2303 m; and (e) 16-16-39-5W5, 2303.6 m

Marine and Petroleum

Geology

1994 V o l u m e

11 N u m b e r

3

315

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al. Table 4 P y r o l y s i s - G C results of the samples studied Sample location

Depth (m)

Sample No.

Cre-Nap

Largest peak

n-alkanes

14-21-39-5W5 14-21-39-5W5 14-21-39-5W5 02-01-39-5W5 02-01-39-5W5 02-01-39-5W5 02-01-39-5W5 12-11-39-5W5 12-11-39-5W5 16-16-39-5W5 16-16-39-5W5 16-16-39-5W5 16-16-39-5W5 16-16-39-5W5 16-16-39-5W5 16-16-39-5W5 16-16-39-5W5 16-16-39-5W5 10-08-39-4W5 10-08-39-4W5 10-08-39-4W5

2285.0 2286.0 2286.0 2319.0 2319.0 2319.0 2319.0 2316.0 2318.0 2303.6 2300.0 2300.0 2300.0 2300.0 2300.0 2300.0 2300.0 2303.0 2239.0* 2239.0* 2239.0*

1- 1 1-2 1-3 2 2 2 2 3-1 a 3-2 4-1a 4-2a 4-2a(4/20) 4-2a(4/40) 4-2a(10/20) 4-2a(10/40) 4-2a(10/40) 4-2a(10/40) 4-3a 5-1a 5-1 b 5-1c

> >= > < < > > H= >+ > > > > > > > > > H= < >

X X C C1 P C 1N,C 1P C C X,C 1N C1 N X,C,C1C,C1 N C C C3N C,C3N C C C X,C1 N X C3N C

-+ ? ++ ++ ? ? + + + ------++ -+ --

* These are different samples recovered from essentially the same depth Cre-Nap is the relative amount of C2 phenol (methylcresol) to naphthalene, i.e. '>" means that C2 phenol > naphthalene. The largest peak was either xylene (X), cresol (methylphenol, C), methylcresol (C1C), methylnaphthalene (C1N), trimethylnaphthalene (C3N} or phenanthrene (P). Relative n-alkane abundance is indicated as absent (-), possibly present (?), low abundance (+) and high abundance (++). Normal operating conditions were 10 mg heated for 20 seconds (10/20); other operating conditions for the 2300.0 m sample from 16-16-39-5W5 are noted

All of the chromatograms are dominated by one or more of four classes of compounds: substituted benzenes (toluene, xylenes), naphthalenes, phenanthrenes and substituted phenols (cresols). Small amounts of n-alkanes (and possibly alkenes) in the C20+ range are visible in some of the chromatograms. Toluene is often the largest peak and, as noted above, where it is smaller it may be the result of operational conditions rather than real differences in the samples. Table 4 lists the analysed samples with qualitative observations on the ratio of the first-eluting methylcresol peak to naphthalene, the largest peak (excluding toluene) and the presence of C20+ n-alkanes. The pyrolysis-GC results fall into two main groups: one in which cresols are dominant and the other in which hydrocarbons (xylenes or naphthalenes) are dominant. The n-alkanes are present in significant amounts only in some of the hydrocarbon-dominated chromatograms. The results appear to be sensitive to the operating temperature. For example, the sample at 2318 m from 2-1-39-5W5 (Table 4) was run four times from a pulverized, and thus presumably homogeneous, aliquot of the coal but the results show a significant level of variability in the relative intensity of the peaks. The relative proportion of high molecular weight to low molecular weight components also appears to be largely the result of differences in the precise pyrolysis conditions. Because the methylnaphthalenes, methylphenanthrenes and n-alkanes are all of a higher molecular weight and later eluting than the cresols, it is unclear whether the variation in analytical results is merely a function of the molecular weight of the products or whether the concentrations of oxygenated species (cresols) result from more vigorous pyrolysis conditions as a result of relative chemical stabilities of the precursors in the coal or of the products themselves. It is thus not possible to definitively characterize these samples on the basis of pyrolysis-GC results. However, within the level of reproducibility (or rather 316

the lack thereof) of the method used, it appears that all the samples have essentially similar chemical properties. The pyrolysis-gas chromatograms are dominated by aromatic compounds (including phenols), which is consistent with derivation from terrestrial organic matter (Larter and Senftle, 1985; Larter et al., 1977). The fluorescence and greasy or oily appearance are thus interpreted to represent: (1) an indigenous bitumen product resulting from the catagenesis of the coal itself rather than staining by crude oil from an external source; (2) only a trace allochthonous component which is not readily apparent in the bulk pyrolysis analysis; or (3) both of the preceding. The absence of n-alkanes from all runs of samples such as that from 2300 m (16-16-39-5W5; Table 4) suggests that there are some genetic differences in the samples and that a refined pyrolysis technique may be useful to separate the different genetic groups. To answer the question about the autochthonous or allochthonous nature of the bitumen, organic geochemical (biomarker) analysis of the oil from the overlying Cretaceous Cardium Formation sandstone is necessary. Such a geochemical comparison of one oil with another as well as between oils and potential source rocks of Devonian to Jurassic age in the study area will undoubtedly elucidate whether the bitumen was generated by these unusual coals themselves or whether it was sourced from a more typical source rock (i.e. an organic-rich shale) and was simply 'picked-up' by the coals while migrating to the reservoir. Further studies need to be conducted to determine, beyond any reasonable doubt, whether the coals were the source and, at the same time, the reservoir of the bitumen. The importance of the results presented is that they may help to solve the question of 'oil from coal'. Although there have been several reviews discussing the possibility that coals could be oil source rocks (e.g. Durand and Paratte, 1983; Saxby and Shibaoka, 1986; Murchison, 1987; Bertrand, 1989), only a few actual proved examples have been published.

Marine and Petroleum Geology 1994 Volume 11 Number 3

Characteristics of Canadian liptinite-rich coals: F. Goodarzi et al. The p y r o l y s i s - G C data may show a slight enrichment of hydrogen in that most of the samples yielded significant amounts of polyaromatic hydrocarbons. However, the normal character associated with petroleum source rocks (dominance by alkene/alkane pairs over aromatic compounds, especially in the C7 to C~2 range) is absent from all samples. This may be the result of unusually hydrogen-rich organic matter (perhydrous vitrinite), or it may simply be reflecting the chemical character of the residual organic matter at a moderately advanced level of thermal maturity.

G C - MS analyses of extracts Analyses by G C - M S of the steranes and terpanes in the solvent extract of samples 37 and 51 (2317.7 m in 12-11-39-5W5 and 2303.1 m in 16-16-39-5W5, respectively) indicate little or no contribution from alloch-

thonous bitumen to the samples. The m/z = 217 and m/z = 218 traces (Figure 8A-8D) are dominated by Cz9 compounds with little or no C27 and C28 contribution visible. Cretaceous crude oils in this basin typically have 27 : 28 : 29 distributions which are close to 1 : 1 : 1, and thus any significant addition of oil should be visible through the presence of C27 and C2s steranes. In the rn/z = 218 trace, the largest peaks after the C29 compounds are derived from the terpanes, which yield a small amount of this mass. These peaks are visible in the sterane trace because of the high terpane/sterane ratio (highest 191/highest 217 ~ 8.80), which is also typical of coals.

Conclusions Based on the above discussion, the following conclusions can be drawn: 1.

(A) 61831

I

I

.

4 m, 205

The greasy appearance and vitrinite fluorescence are most probably due to a small amount of indigenous bitumen which has been generated in response to thermal stress. The samples are slightly enriched in hydrogen compared with most coals, even though the level of thermal maturity appears to be near the end of the 'oil window'. This means that the original coal was probably much enriched in hydrogen. Although the actual source rocks of the bitumen have not been positively identified, there is a strong suspicion, based on the organic petrological and geochemical results presented, that the Mannville

2.

5103

10'

15'

2d

2~

3d

35'

4d

4~

5(

3.

(B)

5076 101

~

92653

15'

2d

25'

30'

35'

46

451

50 I

O l mg 20s

5038

5054 7334

01

151

2~

251

301

351

401

451

50

5126 7779f

I tJ ,=.. 25

5225.

30

35

40

45

50

6 o 4 2 ~ ~

5105 94384

5243-

ld

15'

20'

25'

3d

3d

46

-

45

50

1

,

10' 15' 2d 2~ 30' 3ff 40' 4g sd]

7189.

8

505i

5050 t15~'_

9

9

~

~

10 mg 40 s l

I

10'

9

o nl 20

9_~ 25

~30~

~ ~' 35

Time (min.)

a n~ 45 a~ 40

~

~

=50 Time (min)

Figure 7 Gas chromatograms for multiple pyrolysis runs of (A) a single sample using variable sample weights (about 4 or 10 mg) and pyrolysis times (20 or 40 seconds) and (B) a different sample with more or less identical operating conditions of 10 mg for 20 seconds

Marine and Petroleum Geology 1994 Volume 11 Number 3

317

C h a r a c t e r i s t i c s o f C a n a d i a n l i p t i n i t e - r i c h c o a l s : F. G o o d a r z i e t al.

,oo. m/z 217

¢~

~" ~~' -+

(A)

60

m/z 218

.

~

8o

~,

,3

80

'~ ~

7o go

60

20 lO

++

(B)

5o

+

30

~j

7o

+

50

40

!~

1oo

"i

,o

4o 30 20 lO

o

o

10:00

14:00

18:00

22:00

26:00

30:00

34:00

38:00

10:00

14:00

18:00

Time (rain.)

22:00

26:00

30:00

34:00

38:00

Time (rain.) D:

(C)

100 m/z 217

1 O0

90

m/z

L

90

80

80

70

70

60

60

50

50

(D)

~ og

218

o

40

40

30

30

20

20

10

10

z

~

~

o ,c

o ,c

~ oE E

o lO:OO

14:oo

18:00

22:00

26:00

30:00

34:00

38:00

10:00

14:00

Time (min,)

18:00

22:00 Time

26:00

30:00

34:00

38:00

(rain)

Figure 8 Distribution of steranes in the Mannville coals. (A) 2300 m m/z = 217; (B) 2300 m m/z = 218; (C) 2318 m m/z = 217; (D) 2318 m m/z = 218. For identification of individual sterane compounds, refer to figure

Group coals themselves may have generated the bitumen.

Acknowledgements We thank Drs J. Allan and S. Creaney of Esso Canada, Dr L. D. Stasiuk of the Department of Geology, University of Regina and Dr J. B. Widens of Unocal and an anonymous reviewer for reviewing this paper. We also thank Mrs Kanwal Lali and Mrs Joyce Hollenbeck of the Coal and Hydrocarbon Processing Department, Alberta Research Council and Margaret Northcott and Ron Fanjoy of the Institute of Sedimentary and Petroleum Geology for providing some of the analytical support. Special thanks to Dr I. Banerjee, Geological Survey of Canada, Institute of Sedimentary and Petroleum Geology, for fruitful discussions on the Mannville Group geology. Geological Survey of Canada Contribution Number 59390; Alberta Research Council Contribution Number 2142.

References Allan, J. (1975) Natural and artificial diagenesis of coal macerals PhD Thesis, University of Newcastle-upon-Tyne Allan, J. and Douglas, A. (1974) Alkanes from the pyrolytic degradation of bituminous vitrinites and sporinites. In: Advances in Organic Geochemistry (Eds B. Tissot and F. Bienner), Editions Technip, Paris, 203-206 318

Marine and Petroleum

Geology

1994 V o l u m e

Banerjee, I. (1990) Some aspects of Lower Mannville sedimentation in southeastern Alberta GeoL Surv. Can. Pap. 90-11, 40 pp Banerjee, I. and Goodarzi, F. (1990) Paleoenvironment and sulphur-boron contents of the Mannville (Lower Cretaceous) coals of southern Alberta, Canada Sedim. Geol. 67, 297-310 Bertrand, P. R. (1989) Microfacies and petroleum properties of coals as revealed by a study of North Sea Jurassic coals Int. J. Coal GeoL 13, 575-595 Brooks, J. D. and Smith, J. W. (1967) The diagenesis of plant lipids during the formation of coal, petroleum and natural gas I. Changes in the n-paraffin hydrocarbons Geochim. Cosmochim. Acta 31, 2389-2397 Brooks, J. D. and Smith, J. W. (1969) The diagenesis of plant lipids during the formation of coal, petroleum and natural gas II. Coalification and formation of oil and gas in the Gippsland basin Geochim. Cosmochim. Acta 33, 1183-1194 Cook, A. (1975) The spatial and temporal variation of the type and rank of Australian coals. In: Australian Black Coal (Ed. A. Cook), ABC Symposium, Australasian Institute of Mining and Metallurgy, Illawarra Branch, Melbourne, 63-84 Cooper, B. S. and Murchison, D. G. (1971) The petrology and geochemistry of sporinite. In: Sporopollenin (Ed. J. Brooks, P. R. Grant, M. Muir, P. van Gizel and G. Show), Academic Press, London, 545-568 Creaney, S., Pearson, D. E. and Marconi, L. G. (1980) Anomalous coking properties of Wolgan seam, NSW Australia Fuel 59, 438-440 Durand, B. and Paratte, M. (1983) Oil potential of coals. In: Petroleum Geochemistry and Exploration of Europe (Ed. J. Brooks), Blackwell Scientific, Oxford, 285-292 Espitalie, J. M., Makadi, J. and Trichet, J. (1984) Role of mineral matrix during kerogen pyrolysis Org. Geochem. 6, 365-382

11 N u m b e r

3

Characteristics of Canadian liptinite-rich coals." F. Goodarzi et al. Fowler, M. G., Snowdon, L. R., Brooks, P. W. and Hamilton, T. S. (1988) Biomarker characterization and hydrous pyrolysis of bitumens from Tertiary volcanics, Queen Charlotte Islands, British Columbia, Canada Org. Geochem. 13, 715-725 Fowler, M. G., Gentzis, T., Goodarzi, F. and Foscolos, A. E. (1991) The hydrocarbon potential of some Tertiary lignites from northern Greece as determined by organic petrological and hydrous pyrolysis techniques Org. Geochem. 17, 805-826 Goodarzi, F. (1987) Reflectance and petrology of a burning bituminous coal seam Fuel 66, 1073-1078 Goodarzi, F. and Goodbody, Q. H. (1990) Petrology of Devonian coals from western Melville Island, Arctic Canada and its significance in paleoenvironmental interpretations Int. J. Coal Geol. 14, 175-196 Goodarzi, G., Davies, G. R., Nassichuk, W. W. and Snowdon, L. R. (1987) Organic petrology and Rock-Eval pyrolysis of the Lower Carboniferous Emma Fiord Formation in Sverdrup Basin, Canadian Arctic Archipelago Mar. Petrol GeoL 4, 132-145 Hacquebard, P. E. (1977) Rank of coal as an index of organic metamorphism for oil and gas in Alberta. In: The Origin and Migration of Petroleum in the Western Canadian Sedimentary Basin, Alberta - - A Geochemical and Thermal Maturation Study (Eds G. Deroo, T. G. Powell, B. Tissot and R. G. McCrossan), GeoL Surv. Can. Bull 262, 11-22 Hayes, B. J. R. (1986) Stratigraphy of the Basal Cretaceous Lower Mannville Formation, Southern Alberta and NorthCentral Montana Bull. Can. Petrol Geol. 34, 30-48 Hutton, A. and Cook, A. C. (1980) Influence of alginite in the reflectance of vitrinite from Joadja, N.S.W., and some other coals and oil shales containing alginite Fuel 59, 711-716 International Committee for Coal Petrology (ICCP) (1971) International Handbook of Coal Petrology, 3rd edn, Centre Nationale de la Recherche Scientifique, Paris International Committee for Coal Petrology (ICCP) (1975) International Handbook of Coal Petrology, Supplement to 3rd edition, Centre Nationale de la Recherche Scientifique, Paris Jackson, P. C. (1985) Paleogeography of the Lower Cretaceous Mannville Group of Western Canada. In: Elmworth - - Case Study of a Deep Basin Gas Field (Ed. J. A. Masters), Am. Assoc. Petrol GeoL Mere. No. 38, 49-77 James, D. P. (1985) Sedimentology, paleogeography and reservoir quality of the Mannville Group, southwestern Alberta: implications for exploration Reservoir 12, 2 - 3 Jones, J. M. and Murchison, D. G. (1963) The occurrence of resinite in bituminous coals Econ. GeoL 58, 263-273 Kalkreuth, W. D. (1982) Rank and petrographic composition of selected Jurassic-Lower Cretaceous coals of British Columbia, Canada Bull. Can. Petrol GeoL 30, 112-139 Kalkreuth, W. and Macauley, G. (1987) Organic petrology and geochemical (Rock-Eval) studies on oil shales and coals from the Pictou and Antigonish areas, Nova Scotia, Canada BulL Can. Petrol GeoL 35, 263-295 Khavari-Khorasani, G. (1987) Novel development in fluorescence microscopy of complex organic mixtures: application in petroleum geochemistry Org. Geochem. 11, 157-168 Khavari-Khorasani, G. and Murchison, D. G. (1988) Order of generation of petroleum hydrocarbons from liptinitic macerals with increasing thermal maturity Fuel 67, 1160-1162 Kroger, C. (1968) Der Wachs/Harz-Komplex und das Kohlebitumen Brennstoff Chem. 40, 76-84 Lapo, A. V. (1978) Comparative characteristics of vitrinites of Carboniferous coals of the Ukraine and Jurassic coals of Siberia Fuel 57, 179-183 Lapo, A. V. (1979) "Secondary" macerals of coal Fuel 58, 396-397 Larter, S. R. and Senftle, J. (1985) Improved kerogen typing for petroleum source rock analysis Nature 318, 277-280 Larter, S. R., Horsfield, B. and Douglas, A. G. (1977) Pyrolysis as a possible means of determining the petroleum quality potential of sedimentary organic matter. In: Analytical Pyrolysis (Eds C. E. Rolandfones and C. A. Cranies), Elsevier, Amsterdam, 189-202 Lin, R. and Davis, A. (1988) A fluorogeochemical model for coal macerals Org. Geochem. 12, 363-374 Lin, R., Davis, A., Bensley, D. F. and Derbyshire, F. (1986) Vitrinite secondary fluorescence: its chemistry and relation to the development of a mobile phase and thermoplasticity in coals Int. J. Coal GeoL 6, 215-228

Mackowsky, M-Th (1982) Preparation of published surfaces from particulate samples. In: Coal Petrology (Ed. Stach, E., Mackowsky, M.-Th., Teichmeller, M., Taylor, G. H., Chandra, D. and TeichmL~ller, R.), Gebruder Borntraeger, BerlinStuttgart, 296-299 Moore, L. R. (1968) Cannel coals, bogheads and oil shales. In: Coal and Coal-bearing Strata (Eds D. G. Murchison and T. S. Westoll), Oliver and Boyd, Edinburgh, 19-29 Mukhopadhyay, P. K. and Gormly, J. R. (1984) Hydrocarbon potential of two types of resinite. In: Advances in Organic Geochemistry, 1983 (Eds P. A. Schenck, J. W. Deleeuw and G. W. N. Lijmback), Pergamon Press, Oxford, 439-454 Murchison, D. G. (1976) Resinite: its infrared spectrum and coalification patter Fuel 55, 79-83 Murchison, D. G. (1987) Recent advances in organic petrology and organic geochemistry: an overview with some reference to 'oil from coal'. In: Coal and Coal-bearing Strata: Recent Advances (Ed. A. C. Scott), Spec. PubL GeoL Soc. London No. 32, 257-302 Osadetz, K. G., Pearson, D. E. and Stasiuk, L. D. (1990) Paleogeothermal gradients and changes in the geothermal gradient field of the Alberta Plains. In: Current Research, Part D, GeoL Surv. Can. Pap. 90-1D, 165-178 Peters, K. E. (1986) Guidelines for evaluating petroleum source rocks using programmed pyrolysis Am. Assoc. Petrol GeoL BulL 70, 318-329 Porter, J. W., Price, R. A. and McCrossan, R. G. (1982) The Western Canada Sedimentary Basin Roy. Soc. London Phil. Trans. Ser. A 305, 169-192 Price, L. C. and Barker, C. E. (1985) Suppression of vitrinite reflectance in amorphous rich kerogen - - a major unrecognized problem J. Petrol Geol. 8, 59-84 Saxby, J. D. and Shibaoka, M. (1986) Coal and coal macerals as source rocks for oil and gas AppL Geochem. 1, 25-36 Shibaoka, M. (1978) Occurrence of 'exsudatinite' in brown coals Fuel 57, 798-799 Snowdon, L. R., Brooks, P. W. and Goodarzi, F. (1986) Chemical and petrological properties of some liptinite-rich coals from British Columbia Fuel 65, 460-472 Stach, E. (1982) The lithotype of humic and sapropelic coals. In: Stach's Textbook of Coal Petrology (Ed. E. Stach, Mackowsky, M.-Th., TeichmL~ller, M., Taylor, G. H., Chandra, D. and TeichmL~ller, R.), Gebruder Borntraeger, BerlinStuttgart, 171 - 177 Stasiuk, L. D. (1984) Petrography of Lower Cretaceous Mannville coal from Sparky and Waseca formation, Lloydminster area, Saskatchewan Unpublished Energy Research Unit Contribution No. 4, University of Regina, Regina, Saskatchewan, 18 pp TeichmLiller, M. (1974) Generation of petroleum-like substances in coal seams as seen under the microscope. In : Advances in Organic Geochemistry (Eds B. Tissot and F. Bienner), Edition Technip, Paris, 379-408 Teichm611er, M. (1982) Origin of the petrographic constituents of coal. In: Stach's Textbook of Coal Petrology (Ed. E. Stach, Mackowsky, M.-Th., Teichm611er, M., Taylor, G. H., Chandra, D. and Teichm6ller, R.), Gebruder Borntraeger, BerlinStuttgart, 219-295 Teichm611er, M. (1986) Recent advances in coalification studies and their application to geology. In: Coal and Coal-Bearing Strata: RecentAdvances (Ed. A. Scott), Spec. PubL GeoL Soc. London, 32, 127-169 TeichmOller, M. and Durand, B. (1983) Fluorescence microscopical studies on liptinites and vitrinites in peats and coals, and comparisons of results with Rock-Eval pyrolysis. Int. J. Coal GeoL 2, 197-230 Teichm611er, M. and Ottenjann, K. (1977) Art und diagenese von Liptiniten und lipoiden stoffen in einem Erdolmuttergestein auf Grund fluoreszenmikroskopischer Untersochungen Erdol Kohle Erdgas 30, 387-398 TeichmL~ller, M. and TeichmLWler, R. (1982) Fundamentals of coal petrology. In: Coal Petrology (Ed. E. Stach, Mackowsky, M.-Th., TeichmLiller, M., Taylor, G. H., Chandra, D. and TeichmL~ller, R.), Gebruder Borntraeger, Berlin-Stuttgart, 5-87 Teichm6ller, M. and Wolf, M. (1977) Application of fluorescence microscopy in coal petrology and oil exploration J. Microsc. 109, 49-73

Marine and Petroleum

Geology

1994 Volume

11 N u m b e r

3

319