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2017/03/21 14:00 Dr. Shing-Lin Wang（Department of Oceanography, NSYSU）
Seminar
Poster： ╱ Post date：2017-03-17NCU IHOS Seminar Announcement
Speaker：Dr. Shing-Lin Wang
Place：S-325, Science Building 1
Abstract：
Title：Radiocarbon (14C) dating and tracer studies using the temperature-stepped combustion technique
Speaker：Dr. Shing-Lin Wang
Department of Oceanography, NSYSU
Time：03/21（Tue.）14：00
Place：S-325, Science Building 1
Abstract：
After Libby’s 1946 publication, radiocarbon dating has been widely used to determine the age of carbonaceous materials younger than 50,000 years old in geology and archaeology. With the continuous development of accelerator mass spectrometry (AMS), the sample size for radiocarbon measurement has been reduced from grams in the traditional beta-counting method to milligram and recently to microgram quantities of carbon in AMS analysis. This improvement provides the opportunity to measure radiocarbon content in different carbon fractions of bulk sample while the traditional method could not. Although several techniques can be used to separate different carbon fractions in environmental samples, we have developed a temperature-stepped combustion technique, which is much more efficient and an easier process than the other methods.
We applied the temperature-stepped combustion technique to evaluate the alteration of charcoals and to discriminate different ages of carbon in bulk sediment samples from Taiwan. In this study, we were able to obtain a reasonable age range of the sediment from the mixed carbon sources. More importantly, this technique can also be applied to radiocarbon tracer studies to identify and separate different carbon sources in the environment. For example, in our study of the Kueishantao hydrothermal fluid, we found that mineral-bound carbon is the dominant component of the particulates, and we can use our technique to quantify how such carbon contributes to biological activities. In addition, large amount of old soil is present in river sediments of Taiwan, and this represents deep erosion in the upstream. This process can be quantified using our technique. We can further study the aerosol source of Taiwan by releasing refractory and organic carbon in different temperature, and to assess if Taiwan is in the outflow region of Chinese pollutant. With the help of the temperature-stepped combustion technique and radiocarbon AMS analysis, we will be able to obtain various types of information in different environments, and to further understand the processes of global carbon cycle.
Last modification time：2017-03-17 PM 4:32
