EVENTS ON CLIMATE CHANGE OF YOUNG DRYAS,
DANSGAARD-OESCHGER
AND HEINRICH RECORDED BY HIGH-RESOLUTION dO18, dC13
STABLE
ISOTOPE ANALYSIS OF STALAGMITE
IN NGƯỜM HẬU CAVE, CAO BẰNG PROVINCE, VIETNAM
Nguyễn Đại
Trung, Phạm Thị Thúy, Trần Tân Văn
Vietnam Institute of Geosciences and
Mineral Resources
Corresponding author: trung_nd@yahoo.com
Abstract: Stalagmite specimen (CPTP5), which is 11 cm in length
with the weight of 2 kilograms, was collected in Ngườm Hậu
limestone cave, Phong Nậm commune, Trùng Khánh district, Cao Bằng
province of Vietnam to analyze stable isotope composition of oxygen and carbon
(dO18, dC13) and U/Th dating. The analytical
results are used to interpret the climate changes in the north of Vietnam
during the late Pleistocene - Holocene (approximately
30.000 years ago). A total of 72 samples were collected along both the
growth layers and growth axis of stalagmites to determine stable isotope while
10 samples were gathered only along growth axis to dating. The results showed
that stalagmites ages were from 271 to 28,700 years. Isotope analysis indicated
that dO18, dC13 ranged from 10.317 to -9.407 ‰ and -11.951 to -11.391 ‰, respectively. These results
gave illustrated the paleoclimate conditions exist the cold and warm
period intertwining under 28,700 year ago. There were four climate
events marked the world climate changes in the last glacial period as known as Dansgaard/Oeschger (D/O) 1-2, Heinrich 1(H1) and global
cold Young Dryas (YD). Besides, study area’s climate had
changed to cold period in the nearly year of 8,200 and regional the cold and
warm period intertwining.
Keywords: Stalagmites,
YD, D/O Heinrich events, dO18,
Vietnam
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