Nature Publishing Group, publisher of Nature, and other science journals and reference works
Nature
my account e-alerts subscribe register
   
Tuesday 19 September 2017
Journal Home
Current Issue
AOP
Archive
Download PDF
References
Export citation
Export references
Send to a friend
More articles like this

Letters to Nature
Nature 276, 60 - 64 (02 November 1978); doi:10.1038/276060a0

The Bucegi Conglomerate: a Romanian Carpathian submarine slope deposit

DANIEL JEAN STANLEY* & BRADFORD A. HALL

*Division of Sedimentology, Smithsonian Institution, Washington, D.C. 20560 and Department of Geological Sciences, University of Maine at Orono, Orono, Maine 04473
Department of Geological Sciences, University of Maine at Orono, Orono, Maine 04473

THE Bucegi Conglomerate, a thick conglomerate-sandstone unit of Albian age (Cretaceous), is well exposed in the Eastern Carpathian Chain near Sinaia, Romania. This unit occupies more than 5,000 km2 in the vicinity of the change in structural–stratigraphic trend of the mobile belt from E–W to N–S (Fig. 1a). The thickness of this remarkably coarse series is regionally variable and locally exceeds 2,000 m. To the west the conglomerate overlies, with angular unconformity, Middle and Upper Jurassic platform carbonate rocks which in turn unconformably overlie crystalline basement. To the east, over a distance of approximately 10 km, the Bucegi rests with local unconformity on Neocomian and Barremian–Aptian flysch several kilometres thick (Fig. 1b and c). This unconformity post-dates pre-upper Aptian to post-lower Aptian folding 1,2. Previous work has alluded to the shallow marine and nearshore origin3 of this formation, and it has been frequently referred to as a molasse, or para-molasse4, mainly due to its coarse nature, its pebble shape3,5, its stratigraphic position above sandstone-shale turbidite-rich formations, and presumably also to its ‘post-tectonic’ position within the mobile belt. Here we consider an alternative, that is that the Bucegi Conglomerate accumulated in an infra-neritic to deep marine environment and that it records progradation of coarse material directly onto the slope and base of slope of a turbidite basin. The field observations we made in conjunction with Romanian colleagues in selected sections of the Sinaia region (Jepi Valley, Chindichiu road cuts) and an evaluation of previous reports provide a plausible basis to reconsider the depositional origin of the Bucegi.

------------------

References

1. Patrulius, D., Dimitrescu, R. & Gherasi, N. Carte Géologique 28. Brasov (Institut Géologique, Bucarest, 1968).
2. Burchfiel, B. C. & Bleahu, M. Geol. Soc. Am. Sp. Pap. 158, 1–82 (1976).
3. Mihailescu, N., Panin, N., Jipa, D. & Contescu, L. Geol. Studies Res. Romanian Acad. Sci. 12, 231–236 (1967).
4. Contescu, L. R. Geol. Rdsch. 56, 241–262 (1967).
5. Mihailescu, N. Acta geol. Acad. Scient. Hungaricae 15, 197–205 (1971).
6. Contescu, L. R. Am. Ass. Petrol. Geol. Bull. 58, 2436–2476 (1974).
7. Patrulius, D., Stefanescu, M., Popa, E. & Popescu, I. Guide to Excursion 50AC, Romania (Int. Geol. Cong. Prague, 1968).
8. Hampton, M. A. J. Sed. Petrol. 45, 834–844 (1975).
9. Chamberlain, T. K. Papers in Maring Geology (ed. Miller, R. L.) 42–64 (Macmillan, New York, 1964).
10. Stanley, D. J. Mar. Geol 16, M1–M8 (1974).
11. Davies, I. C. & Walker, R. G. J. Sed. Petrol. 44, 1200–1216 (1974).
12. Walker, R. G. Geol. Soc. Am. Bull. 86, 737–784 (1975).
13. Winn, Jr, R. D. & Dott, Jr, R. H. Geology 5, 41–44 (1977).
14. Carter, R. M. & Norris, R. J. Sediment. Geol. 18, 289–319 (1977).
15. Middleton, G. V. & Hampton, M. A. Marine Sediment Transport and Environmental Management (eds Stanley, D. J. & Swift, D. J. P.) 197–218 (Wiley, New York, 1976).
16. Stanley, D. J. & Unrug, R. Recognition of Ancient Sedimentary Environments (eds Rigby, J. K. & Hamblin, W. K.) 287–340 (Soc. Econ. Paleont. Mineral. Sp. Publ. 16, Tulsa, 1972).
17. Marschalko, R. Carpathian Balkan Geol. Assoc. Proc. 10th Congr. 113–122 (1973).
18. Hendry, H. E. Sedimentology 18, 277–292 (1972).
19. Ricci Lucchi, F. Giorn. Geol., Ann. Museo Geol. Bologna 36, 1–47 (1969).
20. Shideler, G. L. Am. Ass. Petrol. Geol. Bull. 54, 789–806 (1970).
21. Scott, K. M. Am. Ass. Petrol. Geol. Bull. 50, 72–107 (1966).
22. Fisher, R. V. J. Sed. Petrol. 41, 916–927 (1971).
23. Lowe, D. R. J. Sed. Petrol. 42, 89–101 (1972).
24. Shepard, F. P. & Dill, R. F. Submarine Canyons and Other Sea Valleys (Rand McNally, Chicago, 1966).
25. Embley, R. W. Geology 4, 371–374 (1976).
26. Griggs, G. B., Kulm, L. D., Waters, A. C. & Fowler, G. A. J. Geol. 78, 611–619 (1970).



© 1978 Nature Publishing Group
Privacy Policy