SUMMARY
Interpretation of depositional
environments of the Tertiary sedimentary rocks in
Hạ Long area, Quảng Ninh
Hoàng Văn Long
The Tertiary
sedimentary rocks in Hạ Long are distributed eratically as narrow belts and were
considered to be corresponding to the sedimentary rocks in the oil and gas-
bearing Tertiary basins in continental shelf of Việt Nam.
Based on the
integration and processing of the lithological, grain-size and paleontological
data together with detail stratigraphic mapping and field observation, the
Tertiary sedimentary formations in Hạ Long were subdivided into four major lithofacies and corresponding
depositional environments: (1) fluvial-channel crossbedding sandstone; (2)
fluvial-plain coal-bearing mudstone; (3) point-bar fining-upward
gravelly-sandstone; and (4) lacustrine organic-rich shale. The results derived
from lithofacies, depositional environment and regional tectonic studies showed
that the research area has been strongly affected by the Neotectonic
activities, which are mainly characterized by brittle and extensional
deformation together with regional strike-slip motion.
Người biên tập: GS. TS Trần Văn Trị; TS. Phạm Đ́nh Thọ.