Spore-Pollen Biostratigraphy and Paleoecology of Mesozoic and Lower Tertiary Samples from the Surghar and Salt Ranges, Northern Pakistan By N.O. Frederiksen, U.S. Geological Survey T.P. Sheehan, U.S. Geological Survey V.A.S. Andrle, U.S. Geological Survey Chapter D of Regional Studies of the Potwar Plateau Area, Northern Pakistan Edited by Peter D. Warwick and Bruce R. Wardlaw Prepared in cooperation with the Geological Survey of Pakistan, under the auspices of the U.S. Agency for International Development, U.S. Department of State, and the Government of Pakistan Bulletin 2078–D U.S. Department of the Interior U.S. Geological Survey iii Contents Abstract ........................................................................................................................................................D1 Introduction.....................................................................................................................................................1 Acknowledgments ................................................................................................................................1 Previously Reported Ages of Formations ..................................................................................................1 Determination of Spore-Pollen Ages ..........................................................................................................3 Palynological Methods .................................................................................................................................5 Sample Analyses............................................................................................................................................5 Makarwal Coal Field .............................................................................................................................5 Nammal Pass Section ..........................................................................................................................6 Nammal Dam Section ..........................................................................................................................7 Kuraddi Section .....................................................................................................................................7 Samples from the Central and Eastern Salt Range .........................................................................8 Arara Section.........................................................................................................................................9 Nila Wahan Section ..............................................................................................................................9 Drill Hole 9, Khairpur Area ...................................................................................................................9 Nammal Formation ......................................................................................................................9 Patala Formation ..........................................................................................................................9 Lockhart Limestone ...................................................................................................................10 Drill Hole 34, Basharat Area ..............................................................................................................10 Discussion and Conclusions ......................................................................................................................11 References Cited..........................................................................................................................................12 Appendix D1. Alphabetical List of Species Mentioned in this Report ................................................14 Plates [Plates follow Appendix D1] D1. Permian and Jurassic or Early Cretaceous spores and gymnosperm pollen from the Salt Range. D2. Late Jurassic or Early Cretaceous, probably middle Cretaceous, and Paleocene spores and pollen from the Surghar and Salt Ranges. D3. Spores and angiosperm pollen from the Patala Formation of the Salt Range. D4. Angiosperm pollen from the Patala and Nammal Formations of the Salt Range. Figures D1. Map showing the Salt Range study area and selected regional features .......................D2 D2. Map of the Salt Range study area in northern Pakistan showing sample localities discussed in this report ...............................................................................................................2 iv D3. Range chart for 27 stratigraphically significant pollen species and species groups in a composite section for the upper Paleocene of the Lower Indus coal region, Sindh Province .................................................................................................................4 D4–D8. Diagrams showing analyses of spore-pollen assemblages from the— D4. Hangu and Patala Formations of Lumshiwal Nala in the Makarwal coal field .........6 D5. Hangu Formation of Nammal Pass and the Patala Formation of the Nammal Dam, Arara, Kuraddi, and Nila Wahan sections .............................................................7 D6. Patala Formation of various sections in the central and eastern Salt Range ...........8 D7. Patala Formation of drill hole 9, Khairpur area ...............................................................9 D8. Patala and Nammal Formations of drill hole 34, Basharat area ................................10 D9. Diagram showing composite analyses of spore-pollen assemblages from the Hangu, Patala, and Nammal Formations of the Surghar and Salt Ranges .......................11 Table D1. Some stratigraphic units in Sindh Province and in the Surghar and Salt Ranges, Pakistan .......................................................................................................................................D3 Spore-Pollen Biostratigraphy and Paleoecology of Mesozoic and Lower Tertiary Samples from the Surghar and Salt Ranges, Northern Pakistan By N.O. Frederiksen, T.P. Sheehan, and V.A.S. Andrle Abstract ments and can generally be given an age assignment using marine megafossils or microfossils. However, some of the Mesozoic and The conglomerate at the base of the Basharat drill hole 34 Paleocene formations of the region are predominantly nonmarine; (eastern Salt Range), thought to represent the Tobra Formation although marine fossils have been found in these formations in (Permian), contained Permian pollen grains and spores that certain areas, many outcrops lack such fossils. Spores and pollen may be indigenous or may be reworked; thus, the age of this are therefore most useful in providing ages and correlations of conglomerate is uncertain. mainly nonmarine units. Previously published Tertiary spore Two samples from the lower part of Lumshiwal Nala and pollen work in the region includes a description of some late (Makarwal coal field, Surghar Range), probably from the Paleocene or Eocene species from Dandot, in Jhelum District, Lumshiwal Formation, were assigned Late Jurassic to Early Punjab, by Vimal (1952) and a description of many Paleocene spe- Cretaceous and middle Cretaceous (approximately Aptian to cies from northern and southern Pakistan by Frederiksen (1994). Albian) ages, respectively. In the present study of spores and pollen from the Surghar and Salt Ranges, 1 sample was analyzed from the Rocks from the shallow subsurface of the Kuraddi sec- Tobra Formation(?) (Permian(?)), 2 from the Lumshiwal For- tion in the western Salt Range, thought to be possibly from the mation (Mesozoic), 7 from rocks thought at least tentatively Paleocene Hangu Formation, contained spores and pollen grains to represent the Hangu Formation (Paleocene), 26 from the probably of Jurassic to Early Cretaceous age; therefore, these Patala Formation (mainly or entirely Paleocene), and 2 from samples were probably from the Mesozoic Datta Formation. the Nammal Formation (Eocene(?)). Spore-pollen species Rocks mapped as the Hangu Formation at Lumshiwal Nala mentioned in the text and figures are listed in appendix D1. (Surghar Range) and Nammal Pass (western Salt Range) are Many taxa studied are shown in plates D1–D4. Paleocene in age. All analyzed samples of the Patala Formation from the Salt Range appear to be late Paleocene in age and con- tain pollen assemblages similar to those of the Lakhra Formation Acknowledgments of Sindh Province. The Patala assemblages are no older than those from the uppermost part of the Bara Formation of Sindh Prov- This work was done as part of the Coal Resources Explo- ince. Paleocene coal beds in the Hangu and Patala Formations ration and Assessment Program (COALREAP), a collaborative were undoubtedly deposited in or near brackish water because program between the U.S. Geological Survey and the Geologi- dinoflagellate cysts and brackish-water palm pollen of the genus cal Survey of Pakistan. This cooperative program is under the Spinizonocolpites were found in the associated detrital rocks. auspices of the U.S. Agency for International Development Two samples from the Nammal Formation (lower and the Government of Pakistan. Most samples discussed in Eocene(?)) of the Basharat drill hole 34 (eastern Salt Range) had this paper were collected by Frederiksen; however, many of low-diversity spore and pollen assemblages that did not include the Patala samples from the central and eastern Salt Range any species known to be restricted to the Eocene, although some were collected by