Evolutional history of the sea shelf
system in the Southern Central Region in
relationship with sea level fluctuation during Quaternary period
Nguyễn Thế
Tiệp, Ngô Quang Toàn, Đoàn Thị Mai Khanh
The Southern Central Region was extremely affected by climate change
during the Pliocene - Quaternary. The periods of transgressive entering into
the coastal continent, due to the glacial, created 6 sea steps of different
heights: 75-80 m, 50-60 m, 35-40 m, 10-30 m, 4-6 m, and 1-3 m corresponding to
following periods: Donau-Gunz (Late Pliocene), Gunz-Mindel (Late Pleistocene -
Early Qi'), Mindel-Riss (Middle Pleistocene, Early Qra), Riss - Wurm
1 (late of Middle Pleistocene, Late Qi2b), Wurm 1-Wurm 2 (Late
Pleistocene, Early Q]3a) and Flandrian (Middle Holocene). In the
glacial period, the continental shelf in the Southern Central Region created 5
ancient shorelines in the period of the lowest sea level, including: an ancient
coastal zone at a depth of 180-200 m, 40,000-50,000 years in age; an ancient
coastal zone at a depth of 140-150 m, about 15,000-18,000 years in age; an
ancient coastal zone at a depth of 43- 63 m, Early Holocene, early section (14C:
10,100 years); an ancient coastal zone at a depth of 25-30 m, 8,000 years in
age, Early Holocene; and an ancient coastal zone at a depth of 10-15 m, about
7,000 years in age. Based on analysis and synthesis of the sea shelf system and
ancient shorelines, a curve oscillation of the regional sea level was
identified during Pliocene – Quaternary.
Người
biên tập: TS. Nguyễn Tiến Hải