由沉積物穩定氮同位素分析探討臺北盆地過去二十萬年之氣候變遷
Other Title
Climate change of past 200 kys in Taipei Basin using stable nitrogen
isotope analysis of core sediments
isotope analysis of core sediments
Date Issued
2002
Date
2002
Author(s)
DOI
902116M002010
Abstract
In this study, C/N ratios and d 15 N
values of the Wu-ku core sediments were
measured. Combining with d 13 C, the
environmental change can be clearly
understood. Based on the previous study,
Taipei Basin was a lacustrine environment
that could preserve a continuous
sedimentary history of terrestrial
environment. The sedimentation of Taipei
Basin was triggered somewhat after 300ka.
Except that the deposition of the rhythmic
mud layer was affected by the local event,
the environment around Taipei Basin was
mainly controlled by the global change (Wei
et al., 1997; Chen et al., 1999).
Our results show a very good
correlation between C/N and d 13 C.
According to the d 13 C data, Taipei basin
went through a period of time that the d 13 C
shift to a heavy value, implying that C4 plant
was an important source of organic matters.
The flourishing of C4 plant indicates that the
climate was relatively arid during oceanic
isotope stage 2 and 6. From the heavy d 15 N
values at the upper 50m and 330-390m, we
think that one probable reason may be the
recycled nitrate from denitrification was the
important source of nitrogen for the primary
producer, and resulted in heavy d 15 N
(Altabet et al., 1999). The other one could
be the influence of growth of high d 15 N
macrophyte in the semi-salty water of
estuarine environment.
Subjects
Taipei Basin
Wu-ku core
stable
isotope
isotope
C/N ratio
Publisher
臺北市：國立臺灣大學地質科學系暨研究所
Type
report
File(s)![Thumbnail Image]()
Loading...
Name
902116M002010.pdf
Size
395.66 KB
Format
Adobe PDF
Checksum
(MD5):d36c771ae3447330c9fff6a600abcd1c