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A reappraisal of the conditions of deposition of the Maentwrog Beds (Upper Cambrian) at Porth Ceiriad, North Wales

Published online by Cambridge University Press:  01 May 2009

P. K. Bose
P. K. Bose
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta, 700032, India
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Summary

The marine Maentwrog Beds comprise a repetition of sand and mud facies and follow a non-sequence. A shallow water depositional environment is inferred from the nature of the basal unit (with stromatolites and intraformational conglomerate), and hummocky cross-stratification and mud-draped erosion surfaces. The bulk of the formation was deposited between fair weather and storm wave base, the sand facies representing storm depositional events.

Type
Articles
Information
Geological Magazine , Volume 120 , Issue 1 , January 1983 , pp. 73 - 80
Copyright
Copyright © Cambridge University Press 1983

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References

REFERENCES

Aigner, T. 1979. Schill tempestite im Oberen Muschelkalk (Trias, SW-Deutschland) N. Jb. Geol. Palaont. Abh. 157, 326–43.Google Scholar
Bhattacharyya, A., Sarkar, S. & Chanda, S. K. 1980. Storm deposits in the late Proterozoic Lower Bhander Sandstone of Vindhyan Supergroup around Maihar, Satna District, Madhya Pradesh, India. J. Sedim. Petrol. 50, 1327–36.Google Scholar
Bourgeois, J. 1980. A transgressive shelf sequence exhibiting hummocky stratification: the Cape Sebastian Sandstone (Upper Cretaceous), Southwestern Oregon. J. Sedim. Petrol. 50, 681–702.CrossRefGoogle Scholar
Clifton, H. E., Hunter, R. E. & Philips, R. L. 1971. Depositional structures and processes in the nonbarred high-energy nearshore. J. Sedim. Petrol. 41, 651–70.Google Scholar
Collinson, J. D., Elliott, T. & Reading, H. G. 1978. Environments and Facies of Sand Bodies. Sedimentary Research Associates.Google Scholar
Cowie, J. W., Rushton, A. W. A. & Stubblefield, C. J. 1972. A correlation of Cambrian rocks in the British Isles. Geol. Soc. Lond. Special Report, no. 2.Google Scholar
Crimes, T. P. 1970. A facies analysis of the Cambrian of Wales. Palaeogeog. Palaeoclimatol. Palaeoecol. 7, 113–70.CrossRefGoogle Scholar
Dott, R. H. & Bourgeois, J. (in press). Importance of variable bedding sequences of hummocky stratification. Bull. geol. Soc. Amer..Google Scholar
Emery, K. O. 1960. The Sea Off Southern California. New York: Wiley.Google Scholar
Gadow, S. & Reineck, H. E. 1969. Ablandiger Sandtransporten bei Sturmfluten. Seneken bergiana Marit. 1, 63–78.Google Scholar
Goldring, R. & Aigner, T. 1982. Scour and fill: the significance of event separation. In Cyclic and Event Stratification (ed. Einsele, G. and Seilacher, A.), pp. 354–62. Berlin, Heidelberg, New York: Springer.CrossRefGoogle Scholar
Hamblin, A. P. & Walker, R. G. 1979. Storm-dominated shallow marine deposits: the Fernie-Kootenay (Jurassic) transition, Southern Rocky Mountains. Can. J. Earth Sci. 16, 1673–90.CrossRefGoogle Scholar
Harms, J. C. 1975. Stratification and sequence in prograding shoreline deposits. In Depositional Environments as Interpreted from Primary Sedimentary Structures and Stratification Sequences. Soc. Econ. Palaeont. Min., Short Course, no. 2.Google Scholar
Hayes, M. O. 1967. Hurricanes as geological agents: case studies of hurricanes Carla, 1961 and Cindy, 1963. Rep. Invest. no. 16. Bur. Econ. Geol., University of Texas.Google Scholar
Howard, J. D. & Reineck, H. E. 1979. Sedimentary structures of a ‘high energy’ beach to offshore sequence, Ventura Port Hueneme area, California, U.S.A. (abst.) Bull. Am. Ass. Petrol. Geol. 63, 468–69.Google Scholar
Hunter, R. E. & Clifton, H. E. 1982. Cyclic deposits and hummocky cross-stratification of probable storm origin in Upper Cretaceous rocks of the Cape Sebastian area, southwestern Oregon. J. Sedim. Petrol. 52, 127–43.Google Scholar
Johnson, H. 1978. Shallow siliciclastic seas. In Sedimentary Environments and Facies (ed. Reading, H. G.), pp. 207–58. Blackwell Scientific Publications.Google Scholar
Kreisa, R. D. 1981. Storm-generated sedimentary structures in subtidal marine facies with examples from the Middle and Upper Ordovician of Southwestern Virginia. J. Sedim. Petrol. 51, 823–48.Google Scholar
Kulm, L. D., Roush, R. C., Harlett, J. C. & Neudeck, R. H., Chambers, D. M. & Runge, E. J. 1975. Oregon continental shelf sedimentation: Interrelationships of facies distribution and sedimentary processes. J. Geol. 83, 145–75.CrossRefGoogle Scholar
Kumar, N. Sanders, J. E. 1976. Characteristics of shoreface storm deposits: modern and ancient. J. Sedim. Petrol. 46, 145–62.Google Scholar
Nicholas, T. C. 1915. The geology of the St. Tudwal's Peninsula (Carnarvonshire). Q. Jl Geol. Soc. Lond. 71, 83–141.CrossRefGoogle Scholar
Nicholas, T. C. 1916. Notes on the trilobite fauna of the Middle Cambrian of the St. Tudwal's Peninsula (Carnarvonshire). Q. Jl geol. Soc. Lond. 71, 451–72.CrossRefGoogle Scholar
Reineck, H. E. & Singh, I. B. 1972. Genesis of laminated sand and graded rhythmites in storm-sand layers of shelf mud. Sedimentology 18, 123–8.CrossRefGoogle Scholar
Reineck, H. E. & Wunderlich, F. 1968. A classification and origin of flaser and lenticular bedding. Sedimentology 11, 99–104.CrossRefGoogle Scholar
Simons, D. B., Richardson, E. V. & Nordin, C. F. 1965. Sedimentary structures in alluvial channels. In Primary Sedimentary Structures and Their Hydrodynamic Interpretation. Sp. Pub. Soc. Econ. Palaeont. Min. 12, 34–52.Google Scholar
Sternberg, R. W. & McManus, D. A. 1972. Implications of sediment dispersal from long-term bottom-current measurements on the continental shelf of Washington. In Shelf Sediment Transport: Processes and Pattern (ed. Swift, D. J. P., Duane, D. B. and Pilkey, O. H.), pp. 181–94. Dowden, Hutchinson and Ross.Google Scholar
Walker, R. G. 1965. The origin and significance of internal sedimentary structures of turbidites. Proc. Yorks. Geol. Soc. 35, 1–32.CrossRefGoogle Scholar