2011-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/705194摘要：本計畫是台灣&#8213;菲&#63960;賓地體動&#63882;學研究-II的第六個子計畫，去年已經執行一年，主要是針對2008年11月在塔奧（Taal）火山湖的西岸鑽取的一根岩芯進行研究。利用記錄在湖泊岩芯的地球化學資訊反演火山活動事件以及對周圍沉積環境的影響，為研究該地區的構造活動、氣候變化、沉積環境提供資訊。這根岩芯鑽探深度達84米，總取心率為70%，沉積物厚度達65米。這是塔奧火山湖地區的第一根岩芯，也是菲律賓中部地區目前唯一的一支陸上古氣候、古環境岩芯。岩芯已經切割、照相整理、深度記錄和岩性描述，每隔5公分採集了樣品，共取得1398個樣品。在去年（99年度）的計畫中，我們對采自岩芯不同深度的29個樣品進行加速器質譜碳十四定年，得知岩芯涵蓋大約6千年的時間。之後，從1398個岩芯樣品選擇了121個進行了初步的稀酸可溶相的元素分析（包括Ca，Mg，Sr，Fe，Mn，K，Na，Li，Pb）。在今年（100年度）的計畫中，將對更多的岩芯標本進行化學分析，取得TOC，TIC，稀酸可溶相的常量與微量元素含量，並選擇部分重要樣品進行有機碳、氮同位素的測定。根據結果，分出湖泊沉積和火山堆積，釐清這些參數變化的原因，闡述湖泊在氣候、火山活動及其它構造事件影響下的變化，為解釋該區的地體動力機制積累證據。<br> Abstract: The present proposal is the 6th subproposal of an integrated project named Taiwan-Philippine Geodynamic Study — Phase II and it is the second year of the on-going project. The research goal of this subproposal aims to understand sedimentary history, paleoclimate and paleoenvironment as well as volcanic eruption events in Taal volcano area via geochemical proxies retrieved from a 65-m long core. This core was drilled on the western shore of Taal Lake in November 2008. The total drilling depth is 84 m, with a coring recovery yield about 70% and ~65 m thick sediments. This long core was the first drilling in the region and revealed a continuously depositional history of Taal Lake sediments which recorded volcanic eruption events, changes in paleoclimate, vegetation, ecological status and tectonic movements of the Taal Volcanic area. This long core has been cut, logged, photographed and described in its stratigraphy. We have subsampled 1398 samples at the interval of 5 cm from the core. In year 2009-2010, we obtained 29 dates on this core by using AMS radiocarbon in the KECK radiocarbon Lab at UC Irvine, showing this long core containing only 6,100-year deposition. We have conducted preliminarily geochemical analyses on 121 core samples (out of 1398 samples) by ICP-OES measurements (including Ca, Mg, Sr, Fe, Mn, K, Na, Li and Pb) on the phase of 0.5N HCl leaching fine grain sediments. In the current proposal (year 2010-2011), we will carry out analyses of TOC, TIC, acid-leachable elements, 13Corg and 15Norg in more samples from the 1398 samples. We will identify lake sediments and volcanic deposits in the core, describe the geochemical features of the core, and explain the causes and meanings of the parameters. The conclusions to be drawn will contribute to our understanding of the Taal Lake and Volcano history and to the geodynamics of Taiwan-Philippine block as a whole.Taal火山湖泊沉積岩芯地球化學火山活動古氣候和古環境Taal VolcanoLake sediment coreGeochemistryVolcanic activityPaleoclimate and paleoenvironment