SEQUENCE STRATIGRAPHY OF THE QUATERNARY
SEDIMENTS IN THE RED RIVER DELTA AND ITS STRATIGRAPHIC SIGNIFICANCE
Tran Nghi1, Dinh Xuan Thanh1,
Tran Thi Thanh Nhan1), Nguyen Thi Huyen Trang1, Nguyen
Thi Tuyen2,
Ngo Quang Toan3, Hoang Anh
Khien3, Nguyen Thi Phuong Thao1, Tran Thi Dung1,
Tran Ngoc Dien4
1 VNU
University of Science, Vietnam
2 University
of Poitiers, France
3 Vietnam
Union of Geological Sciences, Vietnam
4Marine Geology and Minerals Division.
Corresponding
author: tranhnghi@gmail.com
Abstract: The Red River Delta
is one of the largest mega delta within the SE Asia. Quaternary sediments of
this delta have been derived from various important resources. However, there
are still many scientific and practical issues of the Quaternary sediments that
have not been satisfactorily resolved. Especially, the division of this
formation is supposed to have no reliable scientific basis,
that greatly affects geological mapping and investigation
of mineral resources. This article will present new research results on
establishment of sedimentary cycle and sequence stratigraphy of the
Quaternary sediments within the Red River Delta. Our results show that the
Quaternary formation in the study area has been associated with 5 cycles of sea
level change. The concept and
approaching methods applied in this study are based on
lithofacies association according to the sedimentary systems tracts, which are
characterized by their typical relationship between petrographic
characteristics, quantitative physical sedimentary properties and global
sea level change.
The results have allowed us to identify 5 sediment cycles
corresponding to 5 sequence cycles: (1) the first sequence (Sq1): Early
Pleistocene (Q11); (2) the second sequence (Sq2): early
Pleistocene (Q12a); (3) 3rd sequence (Sq3): Late
Pleistocene (Q12b); (4) 4th sequence (Sq4):
early late Pleistocene (Q13a) and (5) 5th
sequence (Q13b-Q2). Each sequence is composed
of 3 systems tract (LST, TST, HST). Each systems tract
is characterized by a distinctive lithofacies assemblage and is related to
global Sea level change. These 5 sequences can be used for comparison and
linking stratigraphy from the Red River Delta to adjacent areas.
Keywords: Lithofacies,
sequence stratigraphy, sedimentary cycle, systems tract, regression,
transgression, glacial, interglacial.
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