Steep depositional slope and absence of back barrier: The controlling factors of complex lithofacies association in a foreshore beach environment (Southern Balochistan)
Abstract
The Miocene to Pliocene Hinglaj Formation dominantly composed of sandstone and shale is widely exposed in the southern Balochistan stretching from Nal to Bela area and extends upto southwest Ormara, Mekran. The present study aims at to document the depositional environment of the Hinglaj Formation near Nal.
Twelve facies in the 1443 m thick Hinglaj Formation of Nal section have been recognised. The detailed facies analyses indicate a foreshore beach environment. The facies of shale, shale with interbedded sandstone, arenaceous limestone and hummocky cross-stratified sandstone were deposited on the lower shoreface. Bioturbated sandstone and shale clasted sandstone were deposited on lower shoreface to transition zone, whereas the deposition of low angle cross-bedded sandstone, trough cross-bedded sandstone and turriform gastropod shell lag facies are interpreted to have been deposited in upper to middle shoreface environment. The herringbone cross-stratified sandstone with oyester shell fragments represents deposition in swash zone. The facies distribution of these silisiclastic rocks reflects the complex interaction of fluvial and marine processes.
Seven zones of transgressive and regressive complexes have been identified. The transgressive complexes involve the shoreface retreat of the topographically higher parts of the beach during storms and continuous reworking of the sediment input by wave action during fair weather conditions. The shoreface retreat storm events produced shell lag beds of turriform gastropod and oyster which characterize the initial transgression and secondary transgression respectively. On the other hand the regressive complexes originated during the period of prolonged calm and quiescent intervals accompanied with lower reworking, reduced wave energy and sporadic subaerial exposures.
References
Adams, J, JR, Swift, D.J.P., Coleman, J.M., 1988. Bottom currents and fluviomarine sedimentation on the Mississippi Prodelta Shelf, February to May. Geophysical Research, 92, 14585-14609.
Addicott, W.O., 1980. Miocene stratigraphy and fossils, Cape Blanco Oregon. Ore Geology, 42, 87-98.
Aigner, T., 1985. Storm Depositional Systems. Springer-Verlag, New York.
Bannert, D. and Raza, H.A., 1992. The Segmentation of Indo Pakistan Plate. Pakistan Journal of Hydrocarbon Research, 4(2), 5-18.
Blandford, W.T., 1872. Note on the geological Formations seen along the coasts of Balochistan and Persia from Karachi to the head of the Persian Gulf, and some of the Gulf Island. Ibid Records, 5, 41-45.
Boggs, J.R. S., 1987. Principals of sedimentology and stratigraphy. Merrill Publishing Company, Melbourne.
Bourgeois, J., 1980. A transgressive shelf sequence exhibiting hummocky stratification; The Cape Sebastian sandstone (Upper Cretaceous) Southwestern Oregon. Journal of Sedimentary Petrology, 50, 681-702.
Brenchley, P.J., Newall, G., 1982. Storm influenced inner shelf sand lobes in the Caradoc (Ordovician) of Shropshire, England, 52, 1257-1269.
Brenchley, P.J., Newall, G., Stanistreet, I., 1979. A storm surge origion for sandstone beds in an epicontinental platform sequence, Ordovician, Norway. Sedimentary Geology, 22, 185-217.
Byers, C.W., 1974. Shale fissility; relation to bioturbation. Sedimentology, 21, 479-484.
Byers, C.W., 1977. Biofacies pattern in the euxinic basins; A general model. In: Cook, H.E., Enos, P. (Eds.), Deep water carbonate environments. Society of Economic Palaeontologists and Mineralogists, Special Publication, 25, 5-17.
Chamberlain, C.K., 1978. Recognition of trace fossils in cores. In: Basan, P. B. (Ed) Trace fossil concepts. Society of Economic Palaeontologists and Mineralogists, Short Course Notes, 5, 133-183.
Cluff, R.M., 1980. Paleoenvironment of the New Albany Shale Group (Devonian- Mississipian) of Illinois. Journal of Sedimentary Petrology, 50, 767-780.
Cheema, M.R., Raza, S.M., Ahmad, H., 1977. Cenozoic. In: Shah, S.M.I. (Ed), Stratigraphy of Pakistan. Memoir Geological Survey of Pakistan, 12, 56-98.
Cotter, E., 1983. Shelf, paralic and fluvial environments and sea level fluctuations in the origin of the Tuscarora Formation (Lower Silurian) of central Pennsylvania. Journal of Sedimentary Petrology, 53, 25-49.
Crimes, T.P., 1975. The stratigraphical significance of trace fossils. In: Frey, R.W. (Ed), The study of trace fossils, Springer-Verlag, New York, 109-130.
Curray, J.R., 1964. Transgression and regression. In: Miller, R.C., (Ed), Papers in Marine Geology, McMillan, New York,175-203.
Daley, B., 1973. Fluvio-Lacustrine cyclotherms from the Oligocene of Hampshire. Geological Magazine, 110, 235-242.
Davies, R.A. JR., Fox, W.T., 1972. Coastal processes and near shore sand bars. Journal of Sedimentary Petrology, 42, 401-412.
Dott, (JR) R.H., Bourgeois, J., 1982. Hummocky stratification; Significance of its variable bedding sequences. Geological Society of America Bulletin, 93, 663-680.
Driese, S.G., Fischer, M.W., Easthouse. K.A., Marks, G.T., Gogola, A.R., Schoner, A.E., 1991. Model for the genesis of shoreface and shelf sandstone sequences, southern Appalachians; Paleoenvironmental reconstructions of an Early Silurian shelf system. International Association of Sedimentology, Special Publication 14, 309-338.
Duke, W. L., Arnott, R.W.C., Cheel, R.J., 1991. Shelf Sandstone and Hummocky Cross Stratification; new insights on a storm debate. Geology, 19, 625-628.
Easthouse, K.A., Driese, S.G., 1988. Paleobathymetery of a Silurian shelf system; application of proximality trends and trace fossil distributions. Palaios, 3, 473-486.
Ekdale, A.A., Bromley, R.G., Pemberton, S.G., 1984. Ichnology; the use of trace fossils in sedimentology and stratigraphy. Society of Economic Palaeontologists and Mineralogists, Short Course Notes, 15, 317.
Frey, R.W., 1975. The realm of ichnology, its strengths and limitations. In: Frey, R. W. (Ed), The Study of Trace Fossils, Springer-Verlag, New York, 13-38.
Halam, A., Bradshaw, M.J., 1979. Bituminous shales and oolitic ironstones as indications of transgression and regressions. Journal of Geological Society London, 136, 157-164.
Hamblin, A.P., Walker, R.G., 1979. Storm dominated shallow marine deposits, The Fernie-Kootenry (Jurassic) transition, southern Rocky Mountains. Canadian Journal of Earth Sciences, 16, 1673-1690.
Harms, J.C., Southard, J.B., Spreading, D.R. and Walker, R.G., 1975. Depositional environments as interpreted from primary sedimentary structures and stratification sequences. Society of Economic Palaeontologists and Mineralogists, Short Course. 2.
Hart, B.S., Plint, A.G. 1993. Origin of an erosion surface in shoreface sandstone of the Kakwa Member (Upper Cretaceous Cardium Formation, Canada); importance for reconstruction of stratal geometry and depositional history. International Association of Sedimentology Special Publication, 18, 451-467.
Hayden, B. P., Dolan, R., 1979. Barrier Islands, lagoons and marshes. Journal of Sedimentary Petrology, 49, 1061-1072.
Haszeldine, R.S., 1984. Muddy deltas in fresh water lakes and tectonism in the upper Carboniferous Coalfield of NE England. Sedimentology, 31, 811-822.
Hine, A.C., 1979. Mechanism of berm development and resulting beach growth along a barrier spit complex. Sedimentology, 26, 331-351.
Hiscott, R.N., 1982. Tidal deposits of the Lower Cambrian Random Formation, eastern Newfoundland; facies and paleoenvironment. Canadian Journal of Earth Sciences, 19, 2028-2041.
Howard, R.D., 1978. Sedimentology and trace fossils. In: P. B, Basan (Ed.), Trace Fossils Concepts, Society of Economic Palaeontologists and Mineralogists, Short Course Notes 5, 13-47.
H.S.C. (Hunting Survey Corporation Ltd.),1960. Reconnaissance Geology of a Part of West Pakistan; A Colombo Plan Co-operative Project, Toronto, Published for Govt. of Pakistan by Govt. of Canada.
Hunter, R.E., 1977. Terminology of cross-stratified sedimentary layers and climbing ripples structures. Journal of Sedimentary Petrology, 47, 697-706.
Hunter, R.E., Clifton, H.E., 1982. Cyclic deposits and hummocky cross-stratification of probable storm origin in upper Cretaceous rocks of Cape Sebastian area, southwestern Oregon. Journal Sedimentary Petrology, 52, 127-143.
Hunter, R.E., Clifton, H.E., Phillips, R.L., 1979. Depositional processes, sedimentary structures and predicted vertical sequences in barred nearshore systems, southern Oregon coast. Journal of Sedimentary Petrology, 49, 711-726.
Kelling, G., Mullin, P.R., 1975. Graded limestone and limestone-quartzite couplets; possible storm deposits from the Moroccan Carboniferous. Sedimentary Geology, 13, 161-190.
Klein, G.D.V., 1977. Clastic Tidal Facies, Continuing Education Publication Company, Champaign, IL.
Kreisa, R.D., 1981. Storm generated sedimentary structures in sub tidal marine facies with examples from Middle and Upper Ordovician of south western Virginia. Journal of Sedimentary Petrology, 51, 823-848.
Leggett, J.K., 1978. Eustacy and Pelagic regimes in the Iapetus ocean during the Ordovician and Silurian. Earth and Planetary Science Letters, 41, 163-169.
Leggett, J.K., 1980. British lower Paleozoic black shales and paleo-oceanographic significance. Journal of Geological Society London, 137,139-156.
Leithold, E.L., Bourgeois, J., 1984. Characteristics of coarse grained sequences deposited in near shore, wave dominated environment; examples from the Miocene of south-west Oregon. Sedimentology, 31, 749-775.
McCrory, V.L.C., Walker. R.G., 1986. A storm and tidally influenced prograding shoreline-Upper Cretaceous Milk River Formation of Southern Alberta, Canada. Sedimentology, 33, 47-60.
Mount, J.F., 1982. Storm surge ebb origin of hummocky cross stratified units of the Andrews Mountain Member, Campito Formation (Lower Cambrian), White-Inyo Mountains, Eastern California. Journal of Sedimentary Petrology, 52(3), 951-958.
Niedoroda, A.W., Swift, D.J.P., Thorne, J.A., 1989. Modelling shelf storm beds; Control of bed thickness and bedding sequence. In: Shelf sandstones, shelf depositional sequences and petroleum accumulation: a Symposium; Gulf Coast Section, seventh annual research conference proceedings; Society of Economic Palaeontologists and Mineralogists, Tulsa OK, 15-39.
Nummedal, D., Oertal, G.F., Hubbard, D.K., Hine, A.C., 1977. Tidal inlet variability-Cape Hateras to Cape Canaveral. In: Proceedings Coastal Sediments, 77, American Society of Civil Engineers, Charleston, SC, 543-562.
Oertel, G. F., 1987. Back barrier and shoreface control on inlet channel orientation. Coastal Sediments 87, American Society of Civil Engineers, New Orleans, LA, 2022-2029.
Oertel, G. F., Henry, V.J., Foyle, A.M., 1991. Implications of a tide dominated lagoonal process on the preservation of burried channels on a sediment starved continental shelf. In: Swift, D.J.P., Oertel, G. F., Tilman, R. W., Thorne J. A. (Eds), Shelf Sand and Sandstone Bodies; Geometry, Facies and Sequence Stratigraphy. International Association of Sedimentology Special Publication, 14, 379-393.
Pettijohn, F.J., Potter, P.E., Siever, R., 1972. Sand and Sandstone. Springer-Verlag, New York.
Pickerill, R.K., Hurst, J.M., 1983. Sedimentary facies, depositional environments and faunal association of the lower Llandovery (Silurian) Beechill cove Formation, Arisaig, Nova Scotia. Canadian Journal of Earth Sciences, 20, 1761-1779.
Plint, A.G., 1983. Facies, environments and sedimentary cycles in the Middle Eocene, Bracklesham Formation of the Hampshire Basin; Evidence for global sea level changes. Sedimentology, 30, 625-653.
Plint. A.G., 1984. A regressive coastal sequence from the Upper Eocene of Hampshire, southern England. Sedimentology, 31, 213-225.
Plint, A.G., 1988. Sharp based shoreface sequences and "Off shore bars" in the Cardium Formation of Alberta; their relationship to relative changes in sea level. In: C.K. Wilgus, H.W. Posamentier, C. A. Ross, C.G.St.C (Eds), Kendall Sea Level Changes; An Integrated Approach, SEPM Special Publication, 42, 357-370.
Porrenga, D.H., 1967. Glauconite and chamosite as depth indicators in the marine environment. Marine Geology, 5, 495-501.
Reineck, H.E., Singh, I.B., 1980. Depositional Sedimentary Environments, 2nd Edition, Springer-Verlag, Berlin.
Riemersma, P.E., Chan, M.A., 1991. Facies of the lower Ferron sandstone and Blue Gate shale Member of the Mancos Shale; Lowstand and early transgressive facies architecture. In: Swift, D.J.P., Oertel G.F., Tilman, R.W., Thorne, J.A., (Eds.), Shelf Sand and Sandstone Bodies; Geometry, Facies and Sequence Stratigraphy. International Association of Sedimentology, Special Publication, 14, 489-510.
Reinson, G.E., 1984. Barrier Island and associated strandplain systems. In: Walker R.G., (Ed), Facies Models, 2nd Edition. Geoscience Canada, Reprint Series, 1, 119-140.
Rhoads, D.C., Morse, J.W., 1971. Evolutionary and environmental significance of oxygen defficient marine basins. Lethaia 4, 413-428.
Rhoads, D.C., 1975. The Paleoenvironmental significance of trace fossils. In: Frey R. W., (Ed), The study of trace fossils. Springer-Verlag, New York, 147-160.
Sarwar, G., 1992. Tectonic Setting of the Bela Ophiolites, Southern Pakistan. Tectonophysics, 207, 359-381.
Savrda, C.E., Bottjer, A.J., 1986. Trace fossil model for reconstruction of paleooxygenation in bottom waters. Geology, 14, 3-6.
Savrda, C.E., Bottjer, D.J., Gorsline, D.S., 1984. Development of a comprehensive oxygen defficient marine biofacies model; evidence from santa Monica, San Pedro and Santa Barbara Basins, California continental borderland. American Association of Petroleum Geologists Bulletin, 8, 1179-1192.
Schlanger, S.O., Jenkyns, H.G., 1976. Cretaceous ocean anoxic events; causes and consequences. Geological Mijnbouw, 55, 179-181.
Seilacher, A., 1978. Use of trace fossils for recognizing of depositional environments. In: Basan, P.B. (Ed), Trace fossils concept. Society of Economic Palaeontologists and Mineralogists Short Course Notes, 5, 185- 201.
Selley, R.C., 1969. Near shore marine continental sediments of Sirt Basin, Libya. Geological Society of London, 124, 419-453.
Shah, S.M.I., 1977. Stratigraphy of Pakistan. Memoir Geological Survey of Pakistan, 12.
Shepard, F.P., 1960. Gulf coast barrier. In: Shepard F.P, Phleger F., Van Andel T., (Eds.), Recent Sediments, Northwest Gulf of Mexico. Amrican Association of Petroleum Geologist, 197-220.
Swift, D.J.P., Figueireda, A.G., Freeland, G.J., Oertel, G.F., 1983. Hummocky cross- stratification and megaripples; a geologic double standard. Journal of Sedimentary Petrology, 53, 1295-1317.
Swift, D.J.P., Niedoroda, R.J., 1985. Fluid and sediment dynamics on continental shelves. In: Tillman, R.W., Swift, D.J.P., Walker, R.G. (Eds.), Shelf Sands and Sandstone Reservoirs. Society of Economic Palaeontologists and Mineralogists, Short Course Notes, 13, 47-133.
Swift, D.J.P., Hudleson, P.M., Brenner, R.L., Thompson, P., 1987. Shelf construction in a foreland basin; Storm beds, Shelf sand bodies and shelf-slope depositional sequences in the upper Cretaceous Mesaverde Group, Book Cliffs, Utah. Sedimentology, 34, 423-457.
Thom, B.G., Roy, P.S., 1985. Relative sea level and coastal sedimentation in Southeast Australia in the Holocene. Journal of Sedimentary Petrology, 55. 257-264.
Vrendenburg, E.W., 1906. The classification in the Tertiary System in Sind with reference to the zonal distribution of the Eocene Echinoidia described by Duncan and Sladen. India Geological Survey Records, 34, 172-198.
Vrendenburg, E.W., 1909. Report on the geology of Sarawan, Jhalawn, Mekran and the State of Lasbela. Ibid. Records, 38, 189-215.
Walker, R.G., Duke, W.L., Leckie, D.A., 1983. Hummocky Stratification; Significance of its variable bedding sequences; discussion and reply. Geological Society of America Bulletin, 94, 12451251.
Walker, R.G., 1984. Shelf and shallow marine sands. In: Walker, R.G., (Ed), Facies Models, Geosciences Canadian Reprint Series, 1, 141-170.
Walker, R.G., 1985. Geological evidence for storm transportation and deposition on ancient shelf sands and sandstone reservoirs. In: Tillman, R.W., Swift, D.J.P., Walker, R.G., (Eds), Shelf Sands and Sandstone Reservoirs. Society of Economic Palaeontologists and Mineralogists, Short Course Notes, 13, 243-302.
Walker, K.R., Diehl, W.W., 1986. The effect of synsedimentary substrate modification on the composition of Paleocommunities; Paleoecologic Succession revisited. Palaios 1, 65-74.
Whittaker, J.H.M., 1973. "Gutter Casts" A new name and scour and fill structures with examples from the Llandoverian of Ringerike and Malmoya, Southern Norway. Norsk Geology Tidsskr, 53, 403-417.
Wignall, P.B., Sutcliffe, O.E., Clemson, J., Young, E., 1996. Unusual shoreface sedimentology in the Upper Jurassic of the Boulonnais, Northern France. Journal of Sedimentary Petrology, 66, 577- 586.
