Title: Rock
magnetic studies on the hominoid-bearing sediments at Zhupeng, Yuanmou
Basin, southwestern China and its paleoclimatic significance
Source: CHINESE
SCIENCE BULLETIN 50 (15): 1653-1660 AUG 2005
Document Type: Article
Language: English
Abstract: It
has been proposed that paleoclimatic changes and tectonic events
strongly affect hominoid evolution. The Zhupeng section at Yuanmou
Basin, southwestern China, with the hominoid-bearing fluvial-lacustrine
sediments, is an ideal natural laboratory to test this hypothesis. This
study provided an integrated magnetic study, including low-frequency
susceptibility, the anisotropy of magnetic susceptibility,
temperature-dependent susceptibility, hysteresis loops, isothermal
remanent magnetization, and anhysteretic remanent magnetization, on
samples from the Baozidongqing section at Zhupeng. Results show that
the dominant magnetic carrier is hematite, with minor amount of
magnetite. Both the composition and concentration of magnetic minerals
strongly correlate with the lithostratigraphy. At least eight
short-term events defined by higher concentrations of magnetite were
identified. These short events reflect that the subtropical dry-hot
climate is similar to today's climate. Basing on the lithostratigraphic
and rock magnetic results, we suggest that Yuanmou Basin was in a
steady deposition environment from about 11 to 7 Ma, which is
characterized by alternating of long-term torrid-humid climate and
short-term dry-hot climate. Our study provides invaluable environment
information for understanding the climate shift and the relationship
between paleoenvironment and hominoid evolution in southwestern China
during late Miocene.
Author Keywords: Yuanmou
Basin; hominoid; late Miocene; rock magnetism; paleoclimate
KeyWords Plus: RED
BEDS; MYR AGO; HEMATITE; DEPOSITS; PROVINCE; PLATEAU; MIOCENE; CLIMATE;
MONSOON; YUNNAN
Addresses: Yao
HT (reprint author), Chinese Acad Sci, Inst Geol & Geophys,
Paleomagnetism Lab, Beijing, 100029 Peoples R China
Chinese Acad Sci, Inst Geol & Geophys, Paleomagnetism Lab, Beijing,
100029 Peoples R China
Univ Calif Santa Cruz, Isnt Geophys & Planetary Geophys, Santa
Cruz, CA 95064 USA
Publisher: SCIENCE
PRESS, 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA
Subject Category: MULTIDISCIPLINARY
SCIENCES
IDS Number: 974RQ
ISSN: 1001-6538
