Student：Stz-Yuan Wang Supervisor：Prof. En-Chao Yeh Study of Mountain Building Processes of the Hsuehshan Range, Taiwan 雪山山脈造山機制之研究 Student：Stz-Yuan Wang Supervisor：Prof. En-Chao Yeh

Introduction What’s the difference between these mechanisms? There has been many debates and discussion on Taiwan mountain building processes. Based on previous studies, we can summarize how the rocks into Taiwan’s mountain belt as two types: frontal accretion and basal accretion. What’s the difference between these mechanisms?

Shuichangliu Formation Regional background Bounded by Chuchih Fault and Lishan Fault The composition of Hsuehshan Range is metamorphosed terrestrial sediments HR Northern part Central part Southern part   Sule Formation Audi Formation Tatungshan Formation Paleng Formation Tsuku Sandstone Kangkou Formation Shuichangliu Formation Szeleng Sandstone Paileng Formation Hsitsun Formation Ⅰ Penghu Islands Ⅱ Western Plain Ⅲ Western Foothill Ⅳa Hsuehshan Range Ⅳb Backbone Range Ⅴa Taroko Belt Ⅴb Yuli Belt Ⅵ Longitudinal Valley Ⅶ Coastal Range Modified from 陳文山，台灣地質概論，2016 何春蓀，台灣地質概論，1986

Chen et al.(2011)

Motivation We think the previous research is worth to further study The model needs more data to be verification Whether the southern part of the Hsuehshan Range also follow the process of basal accretion. We’ll try to solve problems by… More data in northern part of the HR Analyze the data in southern part of the HR

Method Converted Vitrinite Reflectance(RM) to maximum metamorphic temperature(TM). Vitrinite Vitrinite Reflection One of the primary components of coals and most sedimentary kerogens. TM= ln RM +1.26 0.00811 (Barker and Goldstein, 1990)

林志貴碩士論文，1994 林志貴碩士論文，1994 林清俊碩士論文，2000

Result Taipei-Ilan highway profile Modified from 中央地質調查所，五萬分之一台灣地質圖幅第九、十號

Modified from 中央地質調查所，五萬分之一台灣地質圖幅第九號

Xindian-Wulai highway profile Modified from 中央地質調查所，五萬分之一台灣地質圖幅第九號

Modified from 中央地質調查所，五萬分之一台灣地質圖幅第九號

Southern Cross-island Highway Modified from 李錫堤 等，1977

Modified from 李錫堤 等，1977

Summary We can summarize three observations from the temperature profiles. The temperature do not change along with large- scale structure. TM do not also display the difference that due to the stratigraphic thickness. There might be a fault that caused the change of temperature .

Conclusion Based on the results above, we can have reasonably think as following Northern part of Hsuehshan Range is tend to be basal accretion. Southern part of Hsuehshan Range might be tend to basal accretion inferred from available data.

Future work In these research areas, we found that there are potential irregularities that might be affect by faults. If there might be late tectonic activity in the Hsuehshan Range? What’s the relationship between faults, and whether these fault activities still ongoing?

Reference 林朝宗（2000）。《五萬分之一台灣地質圖幅第九號：新店》。臺北：經濟部中央地質調查所。 黃鑑水、何信昌（2003）。《五萬分之一台灣地質圖幅第十號：頭城》。臺北：經濟部中央地質調查所。 Suppe, J.(1981):《Mechanics of mountain building and metamorphism in Taiwan》.MEMOIR OF THE GEOLOGICALSOCIETY OF CHINA, 4, 1981, pp.67-89. Barker, C.E. and Goldstein, R.H., (1990):《Fluid-inclusion technique for determining maximum temperature in calcite and its comparison to the vitrinite reflectance geothermometer》. Geology, 18, 1990, pp.1003–1006. Simoes, M. et al.(2007):《Mountain building in Taiwan: a thermokinematic model》. J. Geophys. Res., 112, 2007, B11405. Beyssac et al.(2007):《Late Cenozoic metamorphic evolution and exhumation of Taiwan》. TECTONICS, 32, 2007, pp.1-32. Chen et al.(2011):《Nappe structure revealed by thermal constraints in the Taiwan metamorphic belt》. Terra Nova, 23, 2011, pp.85-91. 李錫堤、王源（1985，6）。〈臺灣南部橫貫公路禮觀一帶之地層及構造〉。《地質》，6，頁1­-20。 林志貴（1994）。《烏來–坪林地區漸新世變質泥質岩中鏡煤素反射率之研究》。國立台灣師範大學地球科學所，未出版，臺北。 林清俊（2000）。《南部橫貫公路禮觀地區鏡煤素反光率及其地質意義》。國立台灣師範大學地球科學所，未出版，臺北。

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