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Comments on the paper entitled “The heavy minerals of the Kurnub Sandstone (Early Cretaceous) of Jordan” by S. Nasir and W. Sadeddin
Sedimentary Geology, 68 (1990) 311-314
311
Elsevier Science Publishers B.V., Amsterdam
Comments on the paper entitled "The heavy minerals of the Kurnub Sandstone (Early Cretaceous) of Jordan" by S. Nasir and W. Sadeddin Belal A m i r e h P.O. Box 17788, AI-Samani Post Office Benghazi, LiBya Accepted July 13, 1990
I wish to point out that the conclusions arrived at Nasir and Sadeddin (1989) have in many cases been quoted from Amireh (1987) without due acknowledgment. The following are examples: (1) Nasir and Sadeddin stated in their discussion that the proximity of the Kurnub Sandstone in southern Jordan to its provenance, the Arabian-Nubian Shield, played a role in the enrichment in unstable heavy minerals relative to northern Jordan (p. 106, first column, lines 19-22). This is copied from Amireh (1987, p. 205, lines 3-6). That the Arabian-Nubian Shield represents the source rocks, is recorded in Amireh (1987, p. vi, lines 15-17, and p. 209, lines 19-21). (2) Their conclusion concerning the preservation of the unstable heavy minerals garnet and epidote from intrastratal solution by the primary carbonates deposited during the short Tethys ingressions (p. 106, second column, lines 17-20), is quoted from Amireh (1987, p. vii, lines 1-3, or p. 210, lines 27-32). (3) Their statement that the Kurnub Sandstone was deposited in a stable tectonic setting subsequent to an epeirogenic uplift in the Late Jurassic is referred to Bender (1968, p. 106, second column, lines 3-5), though this is not mentioned by Bender but concluded by Amireh (1987, p. 204, fines 13-15). (4) They recorded the presence of staurolite only in the Kurnub Sandstone of southern Jordan and not in northern Jordan (p. 105, second col0037-0738/90/$03.50
© 1990 - Elsevier Science Publishers B.V.
umn, lines 2-8) and this is quoted from Amireh (1987, p. 73, line 17, and p. 190, lines 8-11). (5) They recorded that garnet is confined to two calcareous horizons in the upper part of the Kurnub Sandstone in northern Jordan (p. 105, first column, fines 16-19), which is quoted from Amireh (1987, p. 103, lines 16-18); the position of the two carbonate layers is found in Amireh (1987, p. 48, lines 12-15). (6) Referring to Morton (1985), they stated that the maturity of the Kurnub Sandstone is attributed to intense chemical weathering (p. 106, second column, fines 9-11), whereas this is actually quoted from Amireh (1987, p. 204, lines 1316). (7) Nasir and Sadeddin's statement that the chemical weathering was not sufficient to dissolve all unstable heavy minerals (p. 106, second column, lines 11-13), is copied from Amireh (1987, p. 204, lines 19-21). (8) The statement that intrastratal solution merely caused corrosion of unstable heavy mineral but not total dissolution, as mentioned in the discussion (p. 106, second column, lines 13-16), is quoted from Amireh (1987, p. 204, lines 34-37). (9) The major conclusion of Nasir and Sadeddin's paper is that the main source of the Kurnub Sandstone is the Paleozoic clastic rocks (p. 106, second column, fines 37-40). Although in the introduction to their paper Bender (1968) and Amireh (1987) are acknowledged as sources for
312 the statement, they subsequently present it as their own conclusion (cf. Amireh, p. 209, lines 21-23). (10) They concluded that the heavy-mineral fraction consists mainly of opaques, zircon, tourmaline, rutile; and less frequently of garnet, epidote, staurolite, anatase, barite and hornblende (p. 106, lines 29-33). All these heavy minerals, except for the last two, have previously been recorded by Arnireh (1987) from the Kurnub Sandstone (p. 103, lines 5-10). M a n y statements and some of the conclusions of Nasir and Sadeddin do not seem to agree with widely accepted facts. For example, their fig. 1, shows a very peculiar outcrop pattern of the Paleozoic and Mesozoic clastic rocks and the basement, which seems to be inconsistent with the text. The contact between the Paleozoic clastic rocks and the basement is drawn along the southwestern side of the Mudawwara (the line between two arrows). Such a contact would imply a major tectonic event having producted a major ESEtrending fault, which does not agree with the prevailing n o r t h - s o u t h trend of Wadi A r a b u Jordan Rift Valley. Indeed, field reconnaissance by the author as well as the recent published work by Weissbord and Nachmias (1986) suggests that the area due south and southwest of Mudawwara and farther south to Saudi-Arabia is entirely covered by early Paleozoic clastic rocks. The terminology used by Nasir and Sadeddin (1989) seems in m a n y cases to be inconsistent and confusing. For instance, the Paleozoic-Mesozoic clastic rocks are denoted as " N u b i a n Series" on the map. This name is never used in the text. Bender (1968), who they quote as the reference for the map, did not use the term " N u b i a n Series" which was first introduced by Schneider et al. (1984) and then adopted and defined by Amireh (1987) to include all the clastic and carbonate sedimentary rocks ranging in age between Early Cambrian and U p p e r Cretaceous. Moreover, there is another discrepancy between the figure caption and the map itself. The caption describes the outcrops as "Paleozoic-Mesozoic clastic series" whereas the map shows outcrops of Paleozoic and Mesozoic clastic and carbonate rocks. In addition, the outcrops of the Nubian Series were not described by Bender (1968); their description was
B.AM[REH first presented by Amireh (1987, p. 2) after modification of Bender's map. In the heavy-mineral assemblage of the Kurnub Sandstone in Jordan, Palestine and Sinai (their table 1), hornblende is only recorded in the upper part of Kurnub Sandstone in southern Jordan. It is highly unusual to find such an unstable heavy mineral in a specific horizon in one locality but not in the equivalent formations in neighbouring areas, such as Nahal Shehoret, Timna Valley, the R a m o n 1 and Sinaf 1 boreholes of southern Palestine, and U m Bogma and Gebel el Foka of southwestern Sinai as reported on by Weissbrod and Nachmias (1986). Hornblende is amongst the most unstable of heavy minerals both with respect to chemical weathering (Pettijohn, 1975) and intrastratal solution (Ffichtbauer, 1974). It is unlikely that it is present in the mature quartz arenites of the Kurnub Sandstone which are derived from Paleozoic clastics rocks, themselves almost devoid of hornblende. Very minor amounts of hornblende are present in the Basal Conglomerate-Bedded Arkose Formation of Early Cambrian age and the lower part of the overlying Massive BrownishWeathered Sandstone Formation of Cambrian age, due to preservation from intrastratal solution by a primary illite-rich matrix (Amireh, 1987). The suggestion that hornblende was derived during the Early Cretaceous from other sources (Nassir and Sadeddin, 1989) is rather curious, as hornblende cannot resist the extensive chemical weathering of the fluviatile environment which prevailed during this period. The active chemical weathering event that produced the mature quartz arenites is further indicated by the development of a paleosol horizon at the base of the Kurnub Sandstone (Amireh, 1987). This paleosol is comparable with modern red-brown earth formed under subhumid to semiarid conditions (Bridges, 1970). Weissbord and Nachmias (1986) questioned the presence of hornblende in the Kurnub Sandstone and the Lower Paleozoic Sandstones as reported by Bender (1968). He recorded that both sandstones contain large quantities, as for example up to 18% of the non-opaque heavy mineral fraction in the Cambrian sandstone whereas tourmaline, on the other hand, does not exceed 10% and m a y
HEAVY MINERALS OF THE KURNUB SANDSTONE
DISCUSSION
even be totally absent. Weissbrod and Nachmias (1986) suggested that the only explanation for the reported occurrence of hornblende is that it had been misidentified: "(5) The possibility of erroneous identification, though not very likely, cannot be entirely ruled o u t . . . Such a result could have been obtained if certain varieties of tourmaline were identified as hornblende, and reported as such." It seems likely that what Bender (1968) and Nasir and Sadeddin (1989) reported as hornblende is actually green tourmaline. What the latter described as cleavage, is no more than striations (Millner, 1962; Boenigk, 1983; Amireh, 1987). Such grains can be ruled out as being hornblende by obtaining a uniaxial negative interference figure. This method was actually used by the writer and W. Schneider (personal communication, 1985) to solve the discrepancy between almost total absence of hornblende throughout the whole of the Nubian Series and the huge quantities reported by Bender (1968). There is a contradiction between the discussion of Nasir and Sadeddin and their conclusions. They state that the relative enrichment of the Kurnub Sandstone in southern Jordan in unstable heavy minerals as compared to northern Jordan is a result of the proximity of this sandstone in the former area to the provenance which is the Arabian--Nubian Shield (p. 106, first column, lines 19-22). But in drawing the conclusions they neglect the above statement and on the contrary conclude that the source rocks consisted only partly of local outcrops of igneous and metamorphic shield rocks, the greater portion being Paleozoic clastic rocks (p. 106, second column, lines 37-46). Nasir and Sadeddin conclude that the heavymineral assemblage garnet, epidote and staurolite indicates a source rock represented by local outcrops of igneous and metamorphic rocks. However, this conclusion does not necessary follow since these heavy minerals can also be supplied by the older Paleozoic Nubian formations. Bender (1968) and Amireh (1987) recorded the presence of garnet and epidote in the following formations of the Nubian Series: the Graptolite Sandstone, the SAbellarifex Sandstone, and the ConulariaNautiloidea Sandstone of Middle Ordovician to
313
Early Silurian age. In the Middle Triassic Ain Musa, Muckheiris and Iraq A1 Amir Formations the assemblage of garnet, epidote and staurolite occurs (Amireh, 1987). To further rule out the existence of such local outcrops of igneous and metamorphic rocks, it should be pointed out that the erosional phase that accompanied and followed the several epeirogenic uplifts which affected the area during the Middle and Late paleozoic (Amireh, 1987) would level them off and they might later be buried by younger sediments as proposed by Weissbrod and Nachmias (1986). Consequently, such local outcrops would never persist until the early Cretaceous. Nasir and Sadeddin, referring to Bender (1968) and Amireh (1987), state that the preservation of garnet and epidote in the two marine horizons within the Kurnub Sandstone indicates a warm and humid climate (p. 106, first column, lines 12-16). This is incorrect, since the warm climate is inferred only from the deposition of carbonates in a shallow marine environment, and the climate has nothing to do with the preservation of unstable heavy minerals. Moreover, Bender (1968) did not suggest that garnet and epidote were presented from intrastratal solution by the primary carbonate, since this concept was first put forward by Amireh (1987, p. vii, lines 1-3, and p. 210, lines 27-32). Nasir and Sadeddin attribute the upward change in the mineral composition (both light and heavy minerals) between the late Precambrianearly Paleozoic and late Paleozoic-Mesozoic sandstones in Jordan mainly to changes in provenance and to modifications produced by weathering and transportation. Since they did not investigate the Lower Paleozoic and Mesozoic clastic rocks, they are in no position to draw such a conclusion. It should be noted here that, though they mention late Paieozoic rocks to occur in Jordan, only the uppermost part of the Permian System outcrops. (Bandel and Khoury, 1981). The real factors that played a role in determining the mineral composition of the lower Paleozoic and Mesozoic sandstones are recorded by Amireh (1987) to be mainly the tectonic setting, the weathering climate, and less significantly the depositional environments
314
and diagenesis (particularly intrastratal solution). Whereas during the Early Paleozoic the source area was always the Arabian-Nubian Shield, during the Mesozoic Era detrital minerals were, in addition, also derived from older clastic rocks. Amireh (1987) arrived at the above conclusions only after a detailed sedimentological, petrographical and geochemical investigation of the lower Paleozoic and Mesozoic clastic rocks which outcrop in Jordan. References Amireh, B., 1987. Sedimentological and petrological interplays of the Nubian Series in Jordan with regard to paleogeography and diagenesis. Ph.D. Thesis, Technical University of Braunschweig, Braunschweig, 232 pp. Bandel, K. and Khoury, H., 1981. Lithostratigraphy of the Triassic in Jordan. Facies, 4: 1-26. Bender, F., 1968. Geologie von Jordanien, 7. Beitr~ige zur Regionalen Geologie der Erde. Gebriider Borntraeger, Berlin, 230 pp. Boenigk, W., 1983. Schwermineralanalyse. Enke, Stuttgart,, 158 pp.
B. AMIREH Bridges, E.M., 1970. World Soils. Cambridge University Press, Cambridge, 89 pp. Fiichtbauer, H., 1974. Sediments and Sedimentary Rocks, lI. Sedimentary Petrology. Wiley, New York, N.Y.; 464 pp. Milner, H.B., 1962. Sedimentary Petrology, 2. Principles and Applications. Allen and Unwin, London, 715 pp. Morton, A.C., 1985. A new approach to provenance studies: electron microprobe analysis of detrital garnet from Middle Jurassic Sandstones of northern North Sea. Sediment. Geol., 32: 553-566. Nasir, S. and Sadeddin, W., 1989. The heavy minerals of the Kurnub Sandstone (Early Cretaceous) of Jordan. Sediment. Geol., 62: 101-107. Pettijohn, E.J., 1975. Sedimentary Rocks. Harper and Row, New York, N.Y, 3rd ed., 628 pp. Schneider, W., Aded, A.M. and Salameh, E., 1984. Mineral content and diagenetic pattern--Useful tools for lithostratigraphic subdivisions and correlation of the Nubian Series --Result of Work in the Wadi Zerqa Ma'in area, Jordan. Geol. Jahrbuch, B53: 55-75. Weissbrod, T. and Nachmias, J., 1986. Stratigraphic significance of heavy minerals in the Late Precambrian-Mesozoic clastic sequence ("Nubian Sandstone") in the Near East. Sediment. Geol., 47: 263-242.
311
Elsevier Science Publishers B.V., Amsterdam
Comments on the paper entitled "The heavy minerals of the Kurnub Sandstone (Early Cretaceous) of Jordan" by S. Nasir and W. Sadeddin Belal A m i r e h P.O. Box 17788, AI-Samani Post Office Benghazi, LiBya Accepted July 13, 1990
I wish to point out that the conclusions arrived at Nasir and Sadeddin (1989) have in many cases been quoted from Amireh (1987) without due acknowledgment. The following are examples: (1) Nasir and Sadeddin stated in their discussion that the proximity of the Kurnub Sandstone in southern Jordan to its provenance, the Arabian-Nubian Shield, played a role in the enrichment in unstable heavy minerals relative to northern Jordan (p. 106, first column, lines 19-22). This is copied from Amireh (1987, p. 205, lines 3-6). That the Arabian-Nubian Shield represents the source rocks, is recorded in Amireh (1987, p. vi, lines 15-17, and p. 209, lines 19-21). (2) Their conclusion concerning the preservation of the unstable heavy minerals garnet and epidote from intrastratal solution by the primary carbonates deposited during the short Tethys ingressions (p. 106, second column, lines 17-20), is quoted from Amireh (1987, p. vii, lines 1-3, or p. 210, lines 27-32). (3) Their statement that the Kurnub Sandstone was deposited in a stable tectonic setting subsequent to an epeirogenic uplift in the Late Jurassic is referred to Bender (1968, p. 106, second column, lines 3-5), though this is not mentioned by Bender but concluded by Amireh (1987, p. 204, fines 13-15). (4) They recorded the presence of staurolite only in the Kurnub Sandstone of southern Jordan and not in northern Jordan (p. 105, second col0037-0738/90/$03.50
© 1990 - Elsevier Science Publishers B.V.
umn, lines 2-8) and this is quoted from Amireh (1987, p. 73, line 17, and p. 190, lines 8-11). (5) They recorded that garnet is confined to two calcareous horizons in the upper part of the Kurnub Sandstone in northern Jordan (p. 105, first column, fines 16-19), which is quoted from Amireh (1987, p. 103, lines 16-18); the position of the two carbonate layers is found in Amireh (1987, p. 48, lines 12-15). (6) Referring to Morton (1985), they stated that the maturity of the Kurnub Sandstone is attributed to intense chemical weathering (p. 106, second column, fines 9-11), whereas this is actually quoted from Amireh (1987, p. 204, lines 1316). (7) Nasir and Sadeddin's statement that the chemical weathering was not sufficient to dissolve all unstable heavy minerals (p. 106, second column, lines 11-13), is copied from Amireh (1987, p. 204, lines 19-21). (8) The statement that intrastratal solution merely caused corrosion of unstable heavy mineral but not total dissolution, as mentioned in the discussion (p. 106, second column, lines 13-16), is quoted from Amireh (1987, p. 204, lines 34-37). (9) The major conclusion of Nasir and Sadeddin's paper is that the main source of the Kurnub Sandstone is the Paleozoic clastic rocks (p. 106, second column, fines 37-40). Although in the introduction to their paper Bender (1968) and Amireh (1987) are acknowledged as sources for
312 the statement, they subsequently present it as their own conclusion (cf. Amireh, p. 209, lines 21-23). (10) They concluded that the heavy-mineral fraction consists mainly of opaques, zircon, tourmaline, rutile; and less frequently of garnet, epidote, staurolite, anatase, barite and hornblende (p. 106, lines 29-33). All these heavy minerals, except for the last two, have previously been recorded by Arnireh (1987) from the Kurnub Sandstone (p. 103, lines 5-10). M a n y statements and some of the conclusions of Nasir and Sadeddin do not seem to agree with widely accepted facts. For example, their fig. 1, shows a very peculiar outcrop pattern of the Paleozoic and Mesozoic clastic rocks and the basement, which seems to be inconsistent with the text. The contact between the Paleozoic clastic rocks and the basement is drawn along the southwestern side of the Mudawwara (the line between two arrows). Such a contact would imply a major tectonic event having producted a major ESEtrending fault, which does not agree with the prevailing n o r t h - s o u t h trend of Wadi A r a b u Jordan Rift Valley. Indeed, field reconnaissance by the author as well as the recent published work by Weissbord and Nachmias (1986) suggests that the area due south and southwest of Mudawwara and farther south to Saudi-Arabia is entirely covered by early Paleozoic clastic rocks. The terminology used by Nasir and Sadeddin (1989) seems in m a n y cases to be inconsistent and confusing. For instance, the Paleozoic-Mesozoic clastic rocks are denoted as " N u b i a n Series" on the map. This name is never used in the text. Bender (1968), who they quote as the reference for the map, did not use the term " N u b i a n Series" which was first introduced by Schneider et al. (1984) and then adopted and defined by Amireh (1987) to include all the clastic and carbonate sedimentary rocks ranging in age between Early Cambrian and U p p e r Cretaceous. Moreover, there is another discrepancy between the figure caption and the map itself. The caption describes the outcrops as "Paleozoic-Mesozoic clastic series" whereas the map shows outcrops of Paleozoic and Mesozoic clastic and carbonate rocks. In addition, the outcrops of the Nubian Series were not described by Bender (1968); their description was
B.AM[REH first presented by Amireh (1987, p. 2) after modification of Bender's map. In the heavy-mineral assemblage of the Kurnub Sandstone in Jordan, Palestine and Sinai (their table 1), hornblende is only recorded in the upper part of Kurnub Sandstone in southern Jordan. It is highly unusual to find such an unstable heavy mineral in a specific horizon in one locality but not in the equivalent formations in neighbouring areas, such as Nahal Shehoret, Timna Valley, the R a m o n 1 and Sinaf 1 boreholes of southern Palestine, and U m Bogma and Gebel el Foka of southwestern Sinai as reported on by Weissbrod and Nachmias (1986). Hornblende is amongst the most unstable of heavy minerals both with respect to chemical weathering (Pettijohn, 1975) and intrastratal solution (Ffichtbauer, 1974). It is unlikely that it is present in the mature quartz arenites of the Kurnub Sandstone which are derived from Paleozoic clastics rocks, themselves almost devoid of hornblende. Very minor amounts of hornblende are present in the Basal Conglomerate-Bedded Arkose Formation of Early Cambrian age and the lower part of the overlying Massive BrownishWeathered Sandstone Formation of Cambrian age, due to preservation from intrastratal solution by a primary illite-rich matrix (Amireh, 1987). The suggestion that hornblende was derived during the Early Cretaceous from other sources (Nassir and Sadeddin, 1989) is rather curious, as hornblende cannot resist the extensive chemical weathering of the fluviatile environment which prevailed during this period. The active chemical weathering event that produced the mature quartz arenites is further indicated by the development of a paleosol horizon at the base of the Kurnub Sandstone (Amireh, 1987). This paleosol is comparable with modern red-brown earth formed under subhumid to semiarid conditions (Bridges, 1970). Weissbord and Nachmias (1986) questioned the presence of hornblende in the Kurnub Sandstone and the Lower Paleozoic Sandstones as reported by Bender (1968). He recorded that both sandstones contain large quantities, as for example up to 18% of the non-opaque heavy mineral fraction in the Cambrian sandstone whereas tourmaline, on the other hand, does not exceed 10% and m a y
HEAVY MINERALS OF THE KURNUB SANDSTONE
DISCUSSION
even be totally absent. Weissbrod and Nachmias (1986) suggested that the only explanation for the reported occurrence of hornblende is that it had been misidentified: "(5) The possibility of erroneous identification, though not very likely, cannot be entirely ruled o u t . . . Such a result could have been obtained if certain varieties of tourmaline were identified as hornblende, and reported as such." It seems likely that what Bender (1968) and Nasir and Sadeddin (1989) reported as hornblende is actually green tourmaline. What the latter described as cleavage, is no more than striations (Millner, 1962; Boenigk, 1983; Amireh, 1987). Such grains can be ruled out as being hornblende by obtaining a uniaxial negative interference figure. This method was actually used by the writer and W. Schneider (personal communication, 1985) to solve the discrepancy between almost total absence of hornblende throughout the whole of the Nubian Series and the huge quantities reported by Bender (1968). There is a contradiction between the discussion of Nasir and Sadeddin and their conclusions. They state that the relative enrichment of the Kurnub Sandstone in southern Jordan in unstable heavy minerals as compared to northern Jordan is a result of the proximity of this sandstone in the former area to the provenance which is the Arabian--Nubian Shield (p. 106, first column, lines 19-22). But in drawing the conclusions they neglect the above statement and on the contrary conclude that the source rocks consisted only partly of local outcrops of igneous and metamorphic shield rocks, the greater portion being Paleozoic clastic rocks (p. 106, second column, lines 37-46). Nasir and Sadeddin conclude that the heavymineral assemblage garnet, epidote and staurolite indicates a source rock represented by local outcrops of igneous and metamorphic rocks. However, this conclusion does not necessary follow since these heavy minerals can also be supplied by the older Paleozoic Nubian formations. Bender (1968) and Amireh (1987) recorded the presence of garnet and epidote in the following formations of the Nubian Series: the Graptolite Sandstone, the SAbellarifex Sandstone, and the ConulariaNautiloidea Sandstone of Middle Ordovician to
313
Early Silurian age. In the Middle Triassic Ain Musa, Muckheiris and Iraq A1 Amir Formations the assemblage of garnet, epidote and staurolite occurs (Amireh, 1987). To further rule out the existence of such local outcrops of igneous and metamorphic rocks, it should be pointed out that the erosional phase that accompanied and followed the several epeirogenic uplifts which affected the area during the Middle and Late paleozoic (Amireh, 1987) would level them off and they might later be buried by younger sediments as proposed by Weissbrod and Nachmias (1986). Consequently, such local outcrops would never persist until the early Cretaceous. Nasir and Sadeddin, referring to Bender (1968) and Amireh (1987), state that the preservation of garnet and epidote in the two marine horizons within the Kurnub Sandstone indicates a warm and humid climate (p. 106, first column, lines 12-16). This is incorrect, since the warm climate is inferred only from the deposition of carbonates in a shallow marine environment, and the climate has nothing to do with the preservation of unstable heavy minerals. Moreover, Bender (1968) did not suggest that garnet and epidote were presented from intrastratal solution by the primary carbonate, since this concept was first put forward by Amireh (1987, p. vii, lines 1-3, and p. 210, lines 27-32). Nasir and Sadeddin attribute the upward change in the mineral composition (both light and heavy minerals) between the late Precambrianearly Paleozoic and late Paleozoic-Mesozoic sandstones in Jordan mainly to changes in provenance and to modifications produced by weathering and transportation. Since they did not investigate the Lower Paleozoic and Mesozoic clastic rocks, they are in no position to draw such a conclusion. It should be noted here that, though they mention late Paieozoic rocks to occur in Jordan, only the uppermost part of the Permian System outcrops. (Bandel and Khoury, 1981). The real factors that played a role in determining the mineral composition of the lower Paleozoic and Mesozoic sandstones are recorded by Amireh (1987) to be mainly the tectonic setting, the weathering climate, and less significantly the depositional environments
314
and diagenesis (particularly intrastratal solution). Whereas during the Early Paleozoic the source area was always the Arabian-Nubian Shield, during the Mesozoic Era detrital minerals were, in addition, also derived from older clastic rocks. Amireh (1987) arrived at the above conclusions only after a detailed sedimentological, petrographical and geochemical investigation of the lower Paleozoic and Mesozoic clastic rocks which outcrop in Jordan. References Amireh, B., 1987. Sedimentological and petrological interplays of the Nubian Series in Jordan with regard to paleogeography and diagenesis. Ph.D. Thesis, Technical University of Braunschweig, Braunschweig, 232 pp. Bandel, K. and Khoury, H., 1981. Lithostratigraphy of the Triassic in Jordan. Facies, 4: 1-26. Bender, F., 1968. Geologie von Jordanien, 7. Beitr~ige zur Regionalen Geologie der Erde. Gebriider Borntraeger, Berlin, 230 pp. Boenigk, W., 1983. Schwermineralanalyse. Enke, Stuttgart,, 158 pp.
B. AMIREH Bridges, E.M., 1970. World Soils. Cambridge University Press, Cambridge, 89 pp. Fiichtbauer, H., 1974. Sediments and Sedimentary Rocks, lI. Sedimentary Petrology. Wiley, New York, N.Y.; 464 pp. Milner, H.B., 1962. Sedimentary Petrology, 2. Principles and Applications. Allen and Unwin, London, 715 pp. Morton, A.C., 1985. A new approach to provenance studies: electron microprobe analysis of detrital garnet from Middle Jurassic Sandstones of northern North Sea. Sediment. Geol., 32: 553-566. Nasir, S. and Sadeddin, W., 1989. The heavy minerals of the Kurnub Sandstone (Early Cretaceous) of Jordan. Sediment. Geol., 62: 101-107. Pettijohn, E.J., 1975. Sedimentary Rocks. Harper and Row, New York, N.Y, 3rd ed., 628 pp. Schneider, W., Aded, A.M. and Salameh, E., 1984. Mineral content and diagenetic pattern--Useful tools for lithostratigraphic subdivisions and correlation of the Nubian Series --Result of Work in the Wadi Zerqa Ma'in area, Jordan. Geol. Jahrbuch, B53: 55-75. Weissbrod, T. and Nachmias, J., 1986. Stratigraphic significance of heavy minerals in the Late Precambrian-Mesozoic clastic sequence ("Nubian Sandstone") in the Near East. Sediment. Geol., 47: 263-242.