為瞭解煤在不同的受熱環境中之變化趨勢。本研究以台灣地區中新世含煤層(木山層、石底層、南莊層)為研究目標，共使用42個實驗室分析樣本與467個文獻樣本進行鏡煤素反射率與Tmax的比對；結果顯示此兩者受地溫梯度影響最甚，但除了地溫梯度外，尚可能受到其它的溫度來源所影響，而這些影響可能來自於火成岩入侵、地溫梯度差異、斷層錯動、地層受熱時間或其他地體構造運動等；其中影響力尤以火成岩的入侵最甚；而此二熱成熟度指標對於溫度的敏感度不同，雖同為中新世含煤地層卻因為不同的加熱時間導致此二熱成熟度指標的相關曲線有著不同的趨勢，顯示Ro%與Tmax對受熱之敏感度不同，但受熱時間愈長將會使得此二因子之相關性愈佳。 Vitrinite reflectance and Tmax have been widely used in the determination of thermal maturity of organic materials. Organic miscelles were decomposed after thermal alteration, then exhibit the increase of vitrinite reflectance and Tmax. The maximum thermal event during burial history can thus be recorded. The purpose of this study is to evaluate the effects of different heating mechanism of Miocene coal-bearing seams in the West Foothill Belt, Taiwan. The scope of this study includes 509 samples with various maturities: 42 samples analyzed in our laboratory, plus 497 analytic data adopted from literatures. Two analytic methods were applied in this study: vitrinite reflectance measurement (Ro%) and Rock-Eval pyrolysis. Influencing factors of thermal maturation include heating temperature and time, volcanic and hydrothermal activities, tectonic and burial deposition, fault rupture and friction, etc. The result indicates that vitrinite reflectance is mostly controlled by geothermal gradient in general. However, the sensitivities of vitrinite reflectance and Tmax are different during early and late stages of thermal maturation. Finally, when the organic material was strongly heated in a short period, such as volcanic activities, it will deviate the trend of Tmax vs Ro% curve derived.
