Sedimentary structures of tidal flats: A journey from coast to inner estuarine region of eastern India |
| |
Authors: | A Chakrabarti |
| |
Institution: | (1) Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, West Bengal, India;(2) 23A P.G.M. Shah Road, 700 033 Kolkata, India |
| |
Abstract: | Sedimentary structures of some coastal tropical tidal flats of the east coast of India, and inner estuarine tidal point bars
located at 30 to 50 kilometers inland from the coast, have been extensively studied under varying seasonal conditions. The
results reveal that physical features such as flaser bedding, herringbone cross-bedding, lenticular bedding, and mud/silt
couplets are common to both the environments. In fact, flaser bedding and lenticular bedding are more common in the point
bar facies during the monsoon months than in the coastal tidal flat environments. Interference ripples, though common in both
the environments, show different architectural patterns for different environmental domains. Interference ripples with thread-like
secondary set overriding the earlier ripple-form, resembling wrinkle marks, are the typical features in estuarine point bars
near the high water region. Because structures which are so far considered as key structures for near-coastal tidal flats
are common to both the environments, caution should be exercised for deciphering palaeo-environments, particularly for Proterozoic
rocks, where one has to depend only on physical sedimentary structures. |
| |
Keywords: | Sedimentary structures estuarine point bar open sea tidal flats monsoon effects |
本文献已被 SpringerLink 等数据库收录! |
|