Stable Isotope Evidence for Hydrocarbon Seepages in the Kenting Mélange at Baoli, Hengchun Peninsula, Taiwan

臺灣恆春半島保力墾丁層中烴滲漏之穩定同位素跡證

王士偉(Shih-Wei Wang) ； 米泓生(Horng-Sheng Mii)

《Collection and Research》 27期 (2014/12) Pp. 95-106

https://doi.org/10.6693/CAR.2014.27.7

摘要

This study focused on the origin of nodular and pipe-like carbonate-cemented mudstones collected from the Kenting Mélange. The stable carbon and oxygen isotope compositions of 22 rock samples were analyzed in total. Results of the analyses showed a large variation in δ^(13)C values that ranged from -45.7 per mille to +10.9 per mille V-PDB (n=68). Among them, δ^(13)C values of 53 subsamples ranged from -45.7 per mille to -10.8 per mille V-PDB, indicating that these carbonate cements were derived from hydrocarbon seepages. This study documents the first discovery of cold-seep carbonates from the Kenting Mélange.

關鍵字

stable isotope ； cold-seep carbonates ； hydrocarbon seepage ； Kenting Mélange ； Hengchun Peninsula

並列摘要

本研究係針對採自恆春半島保力墾丁層，總計22件管狀與結核狀碳酸鹽膠結泥岩標本，從中鑽取68件岩石粉末樣本進行穩定碳、氧同位素分析。分析結果，所有樣本的δ^(13)C數值介於千分之-45.7 至千分之+10.9 V-PDB間，顯示其碳酸鹽中穩定碳同位素之組成變異相當大。然而，其中有53件碳酸鹽樣本的δ^(13)C分析值介於千分之-45.7 至千分之-10.8 V-PDB之間，都是特別負的δ^(13)C同位素值，顯示其形成過程與烴滲漏之地質現象有關；此亦為墾丁層中冷泉碳酸鹽岩之首次報導。

並列關鍵字

穩定同位素 ； 冷泉碳酸鹽岩 ； 烴滲漏 ； 墾丁層 ； 恆春半島