Using Sediments to Probe the Mineral and Geochemistry Proxies between Summer Monsoon and Winter Monsoon in East Asian

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Project title

Code/計畫編號

NSC100-2116-M019-001

Translated Name/計畫中文名

利用沉積物探討東亞夏季季風與冬季季風之礦物與地化指標(II)

Project Coordinator/計畫主持人

Huei-Fen Chen

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Institute of Earth Sciences

Website

https://www.grb.gov.tw/search/planDetail?id=2331450

Year

2011

Start date/計畫起

01-08-2011

Expected Completion/計畫迄

01-07-2012

Bugetid/研究經費

1480千元

ResearchField/研究領域

地球科學
大氣科學

"目前結合中國北方、黃河、長江流域和台灣湖泊的資料，並且整合南中國海和東亞邊緣海之沉積物資料。初步的研究成果已撰寫完成，並證實: (1)熱帶地區之地表沉積物的Ti/Al 比值較溫帶地區為高、(2)湖泊表面乾涸時期之風化殼層，其Ti/Al 比值顯著增加、(3)湖泊和海洋岩芯之Ti/Al 比值較地表沉積物之Ti/Al 比值為低、(4)經過長途搬運入海之河流沉積物，其Ti/Al 比值逐漸降低、(5)高度淘選作用之風成砂的Ti/Al 比值極低。因此Ti/Al 比值可作為判斷化學風化程度的和沙塵暴的指標。本計劃將針對湖泊岩芯中Ti/Al 比值和其他可判斷化學風化的元素比值(如Rb/Sr 與CIA 指標)進行比較。首先將使用宜蘭梅花湖和大湖岩芯進行比較，因其母岩來源顯著不同，前者坐落於盧山層板岩地帶，後者則以砂岩和粉砂岩為主且岩性變化較大。利用其 TOC、Ti/Al、Rb/Sr 與CIA 指標等之相關性探討。此外嘗試使用實驗岩石學的方法，利用台灣西部到東部的泥岩、砂岩、板岩和綠色片岩等四大岩類進行不同反應階段的酸溶與鹼溶試驗，用以模擬酸性和鹼性沉積環境下，各主要元素的溶解和遷移過程，以及計算黏土礦物種類和結晶度的變化。最後，尋求初始原岩成分和礦物結晶度對於這些元素比值在化學風化過程所造成的影響，並瞭解在不同原岩來源的環境下，最具代表性的化學風化指標和冬季季風指標。" "Presently we combined the data from North China, Huaghe River, Yangtze River and Taiwan’s lakes, and collected the data from South China Sea, and the marginal East Asian oceans. Our preliminary results have been finished and concluded that: (1) the Ti/Al ratios of surface sediments in tropical region are higher than those in temperate zone, (2) the Ti/Al ratios in weathering crusts of a drying lake increases abruptly, (3) Ti/Al in marine and lake cores has lower ratio than that in land surface sediments, (4) the fluvial sediments flow into the ocean have decreasing Ti/Al, (5) the aeolain sand processed highly sorting has very low Ti/Al ratio. Therefore, we prove that the Ti/Al ratios in sediments can judge the degree of chemical weathering. This project will focus on the Ti/Al ratios correlating with other chemical elements (ex. Rb/Sr and CIA index) to estimate the degree of chemical weathering. Firstly, we will use the Maihwa Lake and Dahu Lake in Ilan to compare the impacts of their different original rocks, the former is composed of Lushan slate and the latter is composed of sandstone and siltstone. We can compare the relations between TOC, Ti/Al, Rb/Sr and CIA index. In addition, we try to use methods of experimental lithology for four kinds of rocks, including mudstone, sandstone, slate and green schist from western to eastern Taiwan, carrying out in acidic and alkaline solutions during variant step stages. This method can simulate the sedimentary environments under acid and alkali regions. This result will give us the messages about the dissolution and migration of each element, and the variations of clay categories and crystallinity. Finally, we look for how the initial parent rocks and mineral crystallinity to influence the elemental ratios under chemical weathering. Moreover, we can find the most representive indices of chemical weathering and winter monsoon in different parent-rock regions."

Keyword(s)

降雨
風成
K/Rb
Ti/Al
CIA
precipitation
aeolian
K/Rb
Ti/Al
CIA

DSpace CRIS

Using Sediments to Probe the Mineral and Geochemistry Proxies between Summer Monsoon and Winter Monsoon in East Asian

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