Evidence of Mid-Carboniferous Miospore Assemblages from Central Saudi Arabia
Published:January 01, 2000
- PDF LinkChapter PDF
Bernard Owens, John Filatoff, Geoffrey Clayton, Sa’id Al-Hajri, 2000. "Evidence of Mid-Carboniferous Miospore Assemblages from Central Saudi Arabia", Stratigraphic Palynology of the Palaeozoic of Saudi Arabia, Sa’id Al-Hajri, Bernard Owens
Download citation file:
Miospore assemblages recovered from a short interval in well Haradh-601 (HRDH-601), drilled in the southern Ghawar oil field, eastern Saudi Arabia, provide additional palynological evidence for the existence of possible early Namurian deposits in the Arabian Peninsula. Despite the variable state of preservation and the presence of a significant number of undescribed taxa, the assemblages contain a number of stratigraphically significant species including Tricidarisporites dumosus, Vallatisporites vallatus, V. galearis, Spelaeotriletes giganteus, S. owensii and Aratrisporites saharaensis together with a limited number of representatives of the monosaccate pollen Potonieisporites sp., Protohaploxypinus sp., Cannanoropollis janakii and Plicatipollenites malabarensis which suggest a mid-Carboniferous age. Evidence of Late Devonian-early Tournaisian (Strunian) reworking into this interval is noted by the presence of Vallatisporites pusillites, Retispora lepidophyta, Retusotriletes incohatus and Emphanisporites rotatus. Comparisons are made with assemblages of potentially similar age in parts of North Africa.
Precise understanding of the depositional history of Carboniferous sedimentation throughout North Africa and the Gulf regions is frequently hindered by the lack of detailed biostratigraphy. The development of a system of palynologically defined biozones throughout the Carboniferous deposits on the northern margin of Gondwana has been seriously impeded by the paucity of lithologically suitable intervals for investigation and by the almost total absence of independent biostratigraphical controls with which to calibrate any palynomorphs recovered. The absence of this facility continues to make the precise timing of major geological events difficult.
Throughout the entire Arabian Peninsula, Upper Carboniferous sedimentation reflects the influences of the Hercynian orogenic event and the consequences of the Late Carboniferous glaciation on the region. Both of these events additionally had a profound impact on the biological communities. No precise datum is available to indicate when the first sediments were deposited on the post-Hercynian Unconformity although Owens and Turner (1995) have suggested that some are of late Westphalian-early Stephanian age. Conversely the youngest pre-Hercynian sediments dated by palynological methods are those reported by Clayton (1995) and Clayton et al. (this volume) from eastern and northern Saudi Arabia where late Visean and early Namurian ages are suggested. The immediate implication of these findings suggested that the Hercynian Orogeny possibly resulted in a hiatus that extended from the early part of the Namurian to at least the middle part of the Westphalian. In the absence of readily available biostratigraphical data there is no proof that this hiatus was total and it must remain a possibility that localised pockets of Namurian-early Westphalian sediments could have been deposited on the irregular post-Hercynian surface and possibly preserved in pockets during subsequent erosive events.
Stump et al. (1995) have summarised the principal lithostratigraphic subdivisions of the Saudi Arabian Carboniferous. Beneath the Hercynian Unconformity, the deposits are mainly represented by sandstones, minor siltstones and coals and assigned to the Berwath Formation and Khusayyayn Member in the Wajid Outcrop Belt with deposition assumed to have taken place in delta-plain to delta-front settings. Above the unconformity the Juwayl and Unayzah formations composed of variably sorted sandstones, silts and shales are considered to be deposited in a more diverse range of depositionary environments ranging from aeolian to fluvial and shallow-marine. Stump et al. (1995) considered that the highly variable character of the Juwayl Member reflected its deposition infilling all the major irregularities on the post-Hercynian surface with a sequence of fluvial deposits, whilst the Unayzah Formation represented deposition on a more regular flood plain. It was from the equivalents of the lower part of the Unayzah Formation that Owens and Turner (1995) reported Westphalian D to early Stephanian miospore assemblages.
Stratigraphy of Well Haradh-601 and Sample Material
Well Haradh-601 was drilled in the south Ghawar oil field, approximately 300 kilometres (km) east of Riyadh (Figure 1), with in excess of 2,700.0 feet (ft) of sediments penetrated below the base of the Permian Khuff carbonates at 13,880.0 ft. The predominantly silty mudstone sequence with significant sandstone interbeds which occupy 440 ft below the Khuff carbonates, are assigned to the Unayzah Formation largely on the evidence of the lithological characteristics and electric log signatures. This unit overlies a predominantly sandstone unit, approximately 200 ft thick, with a thin grey silty mudstone up to 30 ft thick at its base. It is from this silty mudstone unit that the sample material for the present study was obtained. These deposits overlie thick sandstones interpreted on log characters, to represent the local equivalents of the Tawil Formation of Late Silurian to Early Devonian age (Figure 2).
Five samples of drill cuttings were examined from between 14,480.0 ft and 14,530.0 ft consisting predominantly of pale grey, silty mudstones. All samples were prepared using conventional preparation techniques involving hydrochloric and hydrofluoric acids to digest all carbonate and silicate rock matrix. Recovered organic residues were split to allow the separate examination of a detrital kerogen fraction before the remainder was oxidised using fuming nitric acid for periods of up to 15 minutes. Oxidation times were critical; many of the recovered miospores were initially dark in colour and commonly cracked. Excessive oxidation lead to fragmentation of the individual specimens. It remains unclear whether the original dark colour and brittle character of the residue is a reflection of a local increase in the level of organic maturity or merely represents the effects of a prolonged period of subaerial erosion and oxidation prior to the deposition of the overlying Unayzah Formation.
Haradh-601 Miospore Population
Miospores were recovered in the organic residues although in the cases of two samples, the populations were limited in composition. It is not surprising, in view of the close juxtaposition of the samples and the similarity of their lithological composition, that the recovered miospore populations are sufficiently similar in composition to allow composite interpretation. In general the dominant miospore components in each of the assemblages were simple azonate taxa characterised by either a laevigate, conate or apiculate exine ornamentation. Many of the individual specimens were difficult to determine beyond generic level as a result of their dark colour, cracked and corroded condition. The following composite assemblage appears to characterise the sampled interval:
Punctatisporites irrasus, P. nitidus, P. planus, P. solidus, Calamospora microrugosa, C. pallida, Retusotriletes incohatus, Apiculiretusispora sp., Cyclogranisporites sp., Tricidarisporites dumosus, Anapiculatisporites spinosus Anaplanisporites baccatus, Acanthotriletes persibus, Verrucosisporites cf. microverrucosus, V. nitidus, Raistrickia sp., Camptotriletes sp. cf. C. prionotus, Emphanisporites rotatus, Lycospora pusilla, Densosporites anulatus, D. brevispinosus, D. intermedius, Radiizonates cf. mirabilis, Cingulizonates bialatus, Stenozonotriletes sp., Cymbosporites cyathus, Colatisporites denticulatus, Vallatisporites ciliaris, V. galearis, V. vallatus, V. verrucosus, Kraeuselisporites sp. cf. Hymenozonotriletes scorpius, Spelaeotriletes arenaceus, S. giganteus, S. benghaziensis, S. microspinosus, S. owensii, S. cf. resolutus, Auroraspora solisorta, ?Spencerisporites sp., Retispora lepidophyta, Cribrosporites cribellatus, Aratrisporites saharaensis, Schopfipollenites ellipsoides, Laevigatosporites desmoinesensis, Potonieisporites sp., Protohaploxypinus sp., Cannanoropollis janakii and Plicatipollenites malabarensis.
Dark brown to opaque wood debris, either in the form of irregular or lath-shaped components with individual fragments showing little evidence of rounding, was the dominant component in all of the recovered organic residues, accounting for between 50 to 65 percent of the total. Pale yellow to orange-brown irregular shaped tissue fragments accounted for a further 20 to 30 percent and miospores making up the remainder at 10 to 20 percent of the total. The consistent high level of terrestrially-derived material in the suite of samples suggests that deposition took place in a relative nearshore location. The predominance of wood debris, showing considerable variation in particle size and displaying almost no rounding of individual grains, together with a high level representation of both miospores and tissue debris suggests rapid deposition into a body of water with little current activity.
Previous Palynological Studies of the Carboniferous of Saudi Arabia
The miospore populations recovered from the studied interval in well Haradh-601 appear unique in terms of the previous palynological records in the Arabian Peninsula. Earlier investigations carried out within the framework of the Saudi Aramco-Commission Internationale de Microflore du Paléozoïque (CIMP) project have highlighted the existence of Early Carboniferous microfloras in wells ST-8, Ar’ar-1 (ARAR-1) and Abu Safah-29 (ABSF-29) in northern and central Saudi Arabia and the presence of probable Westphalian D-Stephanian assemblages in northern Saudi Arabia in well ST-8. Consideration of the composition of these assemblages is important in the context of interpreting the age of the Haradh-601 miospore assemblages.
Clayton (1995) and Clayton et al. (this volume) have documented miospore populations from three wells in central and northern parts of Saudi Arabia. In the offshore Arabian Gulf well Abu Safah-29, they documented typical Tournaisian assemblages characterised by the presence of Hymenozonotriletes explanatus, Knoxisporites literatus, Perotrilites perinatus, Vallatisporites vallatus and V. verrucosus which have almost no similarities with the populations recovered from Haradh-601, except for rare examples of Vallatisporites sp.
In core samples recovered from cores in well ST-8, Clayton (1995) reported that the lower part of the sequence was dominated by miospore populations consisting of azonate spores including representatives of Calamospora sp., Punctatisporites minutus and P. planus. Representatives of Spelaeotriletes owensii and S. arenaceus are infrequently present with rare Vallatisporites spp. including V. agadesi. The first record of Schopfipollenites ellipsoides occurred in slightly younger sediments at 4,792.0 ft whilst the first records of representatives of Potonieisporites and Plicatipollenites did not appear until 4,637.0 ft. Based on comparisons with the sequence of palynozones established in Cyrenaica, northeast Libya, Clayton (1995) assigned the oldest part of this sequence to the Prolycospora rugulosa-Spelaeotriletes triangulus (RT) miospore biozone of Loboziak and Clayton (1988) with a latest Visean to early Serpukhovian age. The younger assemblages from above 4,642.0 ft which were characterised by the presence of monosaccate pollen of the genera Potonieisporites and Plicatipollenites and the absence of Spelaeotriletes owensii, were assigned to the younger Plicatipollenites malabarensis-Cannanoropollis janakii (MJ) miospore biozone which ranged in age from early Serpukhovian to ?Moscovian in northeast Libya. The RT-MJ biozonal boundary being placed within the early part of the Serpukhovian at an horizon that probably equates to within the Arnsbergian of the standard European chronostratigraphic scale.
In Ar’ar-1 the presence of miospore populations containing representatives of Densosporites variomarginatus, Spelaeotriletes balteatus, S. owensii, S. triangulus, Vallatisporites agadesi, Diatomozonotriletes fragilis and Radiizonates genuinus between 4,272.0 ft and 4,436.0 ft clearly indicate that this section is comparable to the lower part of the ST-8 sequence and should be assigned to the latest Visean-early Sepukhovian MT Biozone.
In Haradh-601 the presence of representatives of Potonieisporites, Plicatipollenites and Cannanoropollis suggests a strong resemblance to the early Serpukhovian-?Moscovian interval assigned to the MJ Biozone in ST-8. The appearance of this group of monosaccate pollen genera at approximately this horizon in other parts of North Gondwana immediately suggests that the studied interval is not older than the base of the Serpukhovian. The presence of rare examples of Spelaeotriletes owensii in the Haradh-601 section may however permit further precision. This species is reported in Cyrenaica and also in the ST-8 section to become extinct at the top of the preceding RT zone of latest Visean-earliest Serpukhovian age. The occurrence of rare specimens in the present section may therefore indicate that this section is located close to the RT-MJ biozonal boundary.
The only other Carboniferous study documented in detail in Saudi Arabia is that which involved a late Westphalian-Stephanian section from the Al-Khlata Formation equivalent in well ST-8 by Owens and Turner (1995). The miospore populations are unique in that they contain typical components of Late Carboniferous-Early Permian from the Gondwana and Euramerican provinces. Whilst the assemblages include representatives of Potonieisporites, Plicatipollenites and Cannanoropollis which are compatible with the Haradh-601 assemblages, the presence of representatives of the distinctive late Westphalian Euramerican province genera including Laevigatosporites, Latosporites, Punctatosporites, Thymospora, Reticulatisporites Cadiospora, Vestispora and Triquitrites in addition to numerous bisaccate and taeniate bisaccate pollen clearly precludes any possibility of correlation with the Haradh-601 section.
Comparisons with Adjacent Parts of North Gondwana
Two major schemes of palynological subdivision of the Upper Palaeozoic sequences exist in North Africa, one proposed by Massa and Moreau-Benoit (1976) which has been widely applied in the Illizi Basin of Algeria and the Ghadames Basin of Libya, whilst the second which resulted from an earlier CIMP project in Cyrenaica, northeast Libya, was documented by Streel et al. (1988) and Loboziak and Clayton (1988). Independent biostratigraphical calibration of both schemes is minimal but there is critical ammonoid evidence from the Illizi Basin of Algeria which is fortuitously available from the late Visean-early Serpukhovian interval and may be of considerable significance in the interpretation of the Haradh-601 results.
Massa and Moreau-Benoit (1976) described a series of 17 palynozones extending from the Early Devonian to the Moscovian in western Libya, based principally on borehole sections in the Ghadames Basin. In a later paper, Massa et al. (1979) described in more detail the Carboniferous components with six palynozones extending from the Tournaisian to Moscovian equivalents. Palynozone XV is of particular relevance to the comparisons drawn with the Saudi Arabian assemblages. The base of this zone which is placed at the boundary between the “Unite a Collenia” and the top of the underlying M’Rar Formation and is characterised by the appearance of Lycospora pusilla in assemblages which contain Densosporites variomarginatus, Radiizonates genuinus, Grandispora balteata and Vallatisporites sp. A. and is regarded as extending from the late Visean into the lower part of the Serpukhovian. The only taxon in common with the assemblages from Haradh-601 is the long ranging species Lycospora pusilla. By contrast, assemblages from the succeeding Palynozone XVI are marked by significant qualitative and quantitative changes that appear to have more in common with the Haradh-601 assemblages. The base of the zone which is located in the middle of the Assedjefar Formation in the Ghadames Basin and is marked by the appearance of Schulzospora campyloptera, Potonieisporites elegans, Schopfipollenites ellipsoides and Florinites spp. Although there are taxonomic differences between the two regions, the appearance of these monosaccate pollen at this horizon compares closely with the appearance of this group of palynomorphs elsewhere in North Gondwana.
In a revision of the original Massa and Moreau-Benoit scheme, Coquel et al. (1988) added important details. They noted that Densosporites variomarginatus, Radiizonates genuinus, Vallatisporites agadesi and Grandispora balteata all decrease rapidly in abundance at the Visean-Serpukhovian boundary in the upper part of Palynozone XV. They confirmed the appearance of Potonieisporites elegans and Schopfipollenites ellipsoides in the upper part of the zone and significantly recorded the extinction of Spelaeotriletes owensii and the appearance of quantitatively significant numbers of Schulzospora campyloptera at the Palynozone XV-XVI boundary. It should be noted however that the latter species was not recorded in northeast Libya or Saudi Arabia.
The second Libyan scheme, established in Cyrenaica by Loboziak and Clayton (1988) dealt with the early Visean to Ghzelian interval but also lacks any independent biostratigraphical calibration. Two biozones relevant to the current investigation were established to cover late Visean to Moscovian sediments with the boundary between the two biozones located in the lower part of the Serpukhovian. The older biozone, the Prolycospora rugulosa-Spelaeotriletes triangulus (RT) Biozone extends from the late Visean into the early Serpukovian and is characterised by the appearance of the two biozonal index species at the base of the unit. Aratrisporites saharaensis, Vallatisporites agadesi, Radiizonates genuinus and Spelaeotriletes owensii extend into this zone from the underlying early Visean deposits but Loboziak and Clayton (1988) comments that all disappear by the top of the unit with the exception of S. owensii which may continue to exist to the top of the biozonal boundary.
The succeeding Plicatipollenites malabarensis-Cannanoropollis janakii (MJ) Biozone, which extends to a poorly defined point in the Moscovian, is characterised by the appearance of the first monosaccate pollen of the genera Potonieisporites, Plicatipollenites and Cannanoropollis within the early Serpukhovian. This event mirrors their appearance in the upper part of the Assedjefar Formation of early Serpukhovian age in the Ghadames Basin of western Libya (Coquel et al., 1988) and may have comparable analogues in the Namurian deposits of Britain (Clayton et al., 1977) and the Donetz Basin (Teteriuk, 1976). Bisaccate and taeniate bisaccate pollen were not recorded in Cyrenaica until the middle part of the Moscovian (mid-Westphalian), a conclusion subsequently supported by Loboziak et al. (1997) who suggested that taeniate bisaccate pollen do not occur in pre-Westphalian sediments of the Amazon Basin part of northern Gondwana.
Direct comparison with the Cyrenaica dataset would suggest that the miospore assemblages recovered from the section in well Haradh-601 would correlate with the lower part of the MJ Biozone based on the presence of small numbers of Potonieisporites, Plicatipollenites and Cannanoropollis together with rare individuals assigned to Splaeotriletes owensii and Aratrisporites saharaensis. The records of Vallatisporites ciliaris, Kraeuselisporites ornatus, Spelaeotriletes triangulus and S. giganteus would also be compatible with an early Serpukhovian (=Arnsbergian-Chokierian) age.
In a review of late Visean-early Namurian stratigraphical palynology throughout North Africa, Abdesselam-Rouighi et al. (1998) have confirmed the general observations made by previous authors in Libya. Of particular importance is their record of the ammonoid Goniatites striatus, a diagnostic late Visean form, in the middle part of the Assekaifaf Formation. This provides a vital calibration for the other zonation schemes. On the basis of this record, they suggested that Lycospora pusilla appears in the late Visean, Schopfipollenites ellipsoides appears in the uppermost Visean and that representatives of monosaccate genera, such as Florinites and Potonieisporites, appear in the earliest Namurian across North Africa. They further commented that Aratrisporites saharaensis, Densosporites variomarginatus, Vallatisporites agadesi, Radiizonates genuinus and Spelaeotriletes owensii are all common components of the Visean but are absent from the Namurian.
Elsewhere in the region, Kora (1993) has documented palynomorph assemblages from the Abu Thora Formation in the Abu Rodeiyim borehole in the Um Bogma area of west-central Sinai. The diverse assemblages recovered allowed subdivision of the sequence into two assemblage zones but both appear to have more in common with assemblages recorded in the Euramerican Province. The older unit (Assemblage A) was assigned a late Visean age and although the author claims some similarity with the Cyrenaica assemblages, there are no records of the presence of distinctive Gondwanan species such as Vallatisporites agadesi, Radiizonates genuinus, Diatomozonotriletes fragilis or Densosporites variomarginatus. The younger unit (Assemblage B) is clearly western European in affiliation and is assigned a late Namurian-early Westphalian age. No records are made of the appearance of the distinctive association of monosaccate pollen that appear to characterise the early Serpukhovian in Libya or of the presence of any typical early Serpukhovian/early Namurian miospores. It must therefore be assumed that a significant hiatus involving most of the sediments equivalent to the Serpukhovian, occurs in Sinai.
The miospore assemblages recovered from well Haradh-601 contain several examples of miospores with well defined stratigraphical ranges elsewhere in the world the presence of which can only be explained by reworking. The records of Retusotriletes incohatus, Verrucosisporites nitidus, Emphanisporites rotatus and Retispora lepidophyta suggest that much of that reworking was from a late Famennian-earliest Tournaisian (Strunian) source. The records of the zonal index species R. lepidophyta, with its world-wide distribution restricted to the uppermost Famennian and basal Tournaisian strata, is particularly significant. The association has been previously reported in the Tournaisian deposits of the Berwath Formation by Clayton (1995) and Clayton et al. (this volume) and in the Al-Khlata Formation equivalents in well ST-8 in northern Saudi Arabia by Owens and Turner (1995) in addition to numerous unpublished records elsewhere throughout the Arabian Peninsula. This persistent reworking of an uppermost Devonian-earliest Tournaisian (Strunian) association points towards the existence, somewhere within the Arabian Peninsula or adjacent regions, of a substantial development of sediments of that age which were exposed to subaerial erosion throughout at least most of Carboniferous time. Sub-surface evidence for the existence of those deposits has been discovered in well Harmaliyah-51 (HRML-51) (Al-Hajri et al., 1999).
The palynomorph assemblages recovered from the interval between 14,480.0 ft and 14,530.0 ft in well Haradh-601 are diverse in composition and contain infrequent representatives of the monosaccate pollen genera Potonieisporites, Plicatipollenites and Cannanoropollis together with isolated specimens of Spelaeotriletes owensii. This association suggests an early Serpukhovian (Arnsbergian-Chokierian) age for the interval.
This is the first suggestion of earliest Namurian-pre late Westphalian sediments in the Arabian Peninsula and implies that the hiatus caused by the Hercynian Orogeny was not total and that it is possible that, from time to time, local basins of fluvial or lacustrine deposition may have become established on the Hercynian land surface.
Sediment input into this small early Serpukhovian basin of deposition contains evidence of the continued existence of erosion of a landmass formed of uppermost Famennian-earliest Tournaisian (Strunian) sediments which provided a source of material from the Tournaisian to the late Westphalian over a large tract of the Arabian Peninsula.
Miospore assemblages recovered from Haradh-601 reflect the continued Gondwanan character of the flora in contrast to assemblages from Sinai, which are clearly more European in aspect. Bearing in mind the European character of the late Westphalian Assemblages from well ST-8 in northern Saudi Arabia, it is probable that a major phytogeographical boundary existed in the northern part of the Arabian Peninsula during Late Carboniferous times.
The authors are grateful to the management of Saudi Aramco and the Saudi Arabian Ministry of Petroleum and Minerals for permission to publish this study.
List of all taxa cited in this report with full author citations
Anaplanisporites baccatus Hoffmeister, Staplin and Malloy, 1955
Anapiculatisporites spinosus (Kosanke) Potonie and Kremp, 1955
Aratrisporites saharaensis Loboziak, Clayton and Owens, 1986
Auroraspora solisorta Hoffmeister, Staplin and Malloy, 1955
Calamospora microrugosa (Ibrahim) Schopf, Wilson and Bentall, 1944
Calamospora pallida (Loose) Schopf, Wilson and Bentall, 1944
Camptotriletes sp.cf .C. prionotus Higgs, 1975
Cannanoropollis janakii Potonie and Sah, 1960
Cingulizonates bialatus (Waltz) Smith and Butterworth, 1967
Colatisporites denticulatus Neville, 1973
Cribrosporites cribellatus Sullivan, 1964
Cymbosporites cyathus Allen, 1965
Densosporites anulatus (Loose) Schopf, Wilson and Bentall, 1944
Densosporites brevispinosus Hoffmeister, Staplin and Malloy, 1955
Densosporites intermedius Butterworth and Williams, 1958
Densosporites variomarginatus Playford, 1963
Diatomozonotriletes fragilis Clayton, 1973
Emphanisporites rotatus (McGregor) McGregor, 1973
Grandispora balteata (Playford) Playford, 1971
Hymenozonotriletes explanatus (Luber) Kedo, 1963
Knoxisporites literatus (Waltz) Playford, 1962
Kraeuselisporites sp. cf. Hymenozonotriletes scorpius Balme and Hassell, 1962
Kraeuselisporites ornatus (Neves) Owens, Mishell and Marshall, 1976
Laevigatosporites desmoinesensis (Ibrahim) Schopf, Wilson and Bentall, 1944
Lycospora pusilla (Ibrahim) Somers, 1972
Plicatipollenites malabarensis (Potonie and Sah) Foster, 1975
Perotrilites perinatus Hughes and Playford, 1961
Potonieisporites elegans (Wilson and Kosanke) Wilson and Venkatachala, 1964
Prolycospora rugulosa (Butterworth and Spinner) Turnau, 1978
Punctatisporites irrasus Hacquebard, 1957
Punctatisporites minutus Kosanke, 1950
Punctatisporites nitidus Hoffmeister, Staplin and Malloy, 1955
Punctatisporites planus Hacquebard, 1957
Punctatisporites solidus Hacquebard, 1957
Radiizonates genuinus (Jushko) Loboziak and Alpern 1978
Radiizonates cf. mirabilis Phillips and Clayton, 1980
Retispora lepidophyta (Kedo) Playford, 1976
Retusotriletes incohatus Sullivan, 1964
Schopfipollenites ellipsoides (Ibrahim) Potonie and Kremp, 1954
Schulzospora campyloptera (Waltz) Hoffmeister, Staplin and Malloy, 1955
Spelaeotriletes arenaceus Neves and Owens, 1966
Spelaeotriletes balteatus (Playford) Higgs, 1975
Spelaeotriletes benghaziensisLoboziak and Clayton, 1988
Spelaeotriletes giganteusLoboziak and Clayton, 1988
Spelaeotriletes microspinosus Neves and Ioannides, 1974
Spelaeotriletes owensii Loboziak and Alpern, 1978
Spelaeotriletes cf. resolutus Higgs, 1975
Spelaeotriletes triangulus Neves and Owens, 1966
?Spencerisporites radiatus (Ibrahim) Felix and Parks, 1959
Tricidarisporites dumosus (Staplin) Sullivan and Marshall, 1966
Vallatisporites agadesi Loboziak and Alpern, 1978
Vallatisporites ciliaris (Luber) Sullivan, 1964
Vallatisporites galearis Sullivan, 1964
Vallatisporites pusillites (Kedo) Dolby and Neves, 1970
Vallatisporites vallatus Hacquebard, 1957
Vallatisporites verrucosus Hacquebard, 1957
Verrucosisporites microverrucosus Ibrahim, 1933
Verrucosisporites nitidus (Naumova) Playford, 1964
ABOUT THE AUTHORS
Bernard Owens (see page 17)
John Filatoff is a Specialist Geologist (Palynologist) with the Saudi Arabian Oil Company as a member of the Exploration Support Team within the Geological Research and Development Division. His activities, since joining the company in 1992, focused initially on Tertiary, Red Sea exploration and, in the past four years, on Palaeozoic deep-gas exploration in Central and Eastern Saudi Arabia. John has 30 years of oil industry experience, mostly in Australia, but also in Iran, Venezuela and now Saudi Arabia. He holds BSc and PhD degrees in Geology from the Universities of Queensland and Western Australia, respectively. John is a member of the DGS, GSA, AASP and CIMP professional societies.
Geoffrey Clayton (see page 153)
Sa’id Al-Hajri (see page 17)