九份-金瓜石地區火成作用對有機物成熟度之影響

Influence of volcanic activities to organic maturation in Jiufen-Chinkuashih Area.

黎易辰(Yi-Cheng Lee)

指導教授 ： 蔡龍珆

國立中央大學/地球科學學院/應用地質研究所/碩士(2008年)

摘要

影響有機質鏡煤素反射率參數變化的因素，有受熱溫度、受熱時間長短、火成活動、熱水礦液、構造運動和沉積深埋等。有機質在地層中受熱後分解重組，使得化學分子排列更緊密，鏡煤素反射率提高，尤以火成岩入侵和熱水作用影響最大。本研究在九份基隆山登山入口和復山金礦採集煤樣本，測定其鏡煤素反射率與熱裂分析，觀察該地區在歷史上是否曾經受到熱水作用或火成岩入侵，並利用反射率推算出當時該地最高受熱溫度和平均溫度。
結果顯示金瓜石礦化地區之鏡煤素受火成作用，反射率可由0.5~0.7%提高至1.1~3.0%，而受熱水作用的地區，反射率可提高到2.0~7.0%，依照鏡煤素反射率測定結果分析，在復山金礦武丹坑口所採集到樣本1、3和樣本4受到熱水作用的機會很大，反射率最高可達5.59%，最高熱水作用溫度可能達到500~600°C之間， 為研究區域溫度最高點， 平均熱水作用溫度約在460~560°C。

關鍵字

鏡煤素反射率 ； 火成活動 ； 熱水礦液 ； 九份-金瓜石

並列摘要

ABSTRACT
Influencing factors of vitrinite reflectance include heated temperature and time, volcanic and hydrothermal activities, tectonic and burial deposition, etc. Organic miscelles decompose after being heated and leading to the increase of vitrinite reflectance. The influence of volcanic and hydrothermal activities is especially notice-worthy. Coal samples were collected from Jiufen-Jilong Shan
and Fushan gold mine area in this study. Vitrinite reflectance and Rock-Eval pyrolysis were then performed to evaluate the influence of past igneous intrusion as well as hydrothermal deposits.Maximum and average heated temperature can thus be estimated.
The results indicate that in the study area, Ro increased from 0.5-0.7% to 1.1-3.0% in the nearby of intruded igneous bodies, where as Ro increased up to 2.0~7.0% in areas close to hydrothermal ore deposits. Samples #1,3and4 were especially affected by hydrothermal deposits with Ro~5.59%. The heated temperatures were estimated as 500~600°C maximum and 460~560°C in average.

並列關鍵字

hydrothermal activities ； vitrinite reflectance ； Ro

參考文獻

ASTM, 1977, Classification of coals by rank, D 388-77.

Barker, C.E.,1983, Influence of time on metamorphism of sedimentary organic matter in liquid-dominated geothermal systems,western North America:Geology, V.11, p.384-388.

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,V.18, p.1003-1006.

Baskin, D. K., 1997, Atomic H/C ration of kerogen as an estimate of thermal maturity and organic matter conversion, The American Association of Petroleum Geologists Bulletin, V.81, N.9, pp.1431-1450.

Burgess, J. D., 1974, Microscopic examination of kerogen ( dispersed organic matter) in petroleum exploration, Geol. Soc. Am. Special Paper 153, pp.19-30.