CAJ | 학술논문

土壤蚀变碳酸盐(?C)是油气化探的一个重要指标，在油气化探中得到广泛的使用，并取得了较好的效果。然而由于对?C 的碳源及其具体矿物形态相知较少，导致该法在业内存在一定的质疑。本文通过对不同地区地表土壤样品、海底沉积物以及钻井岩屑样品进行对比分析，研究其碳源、分布特征及矿物形态。结果表明，不同化探样品中?C的含量与所处的地质环境有关，陆地地表土壤样品中?C的含量普遍较高，其次为海底沉积物样品，钻井岩屑样品中的最低；而钻井岩屑样品(还原环境)中?C 的δ13C 值比地表土壤样品及海底沉积物样品(近地表氧化环境)都要偏轻；由此推测形成?C的碳源有无机、有机以及混合源三种，各种来源的 C 对?C 的贡献因化探样品所处的地质环境的不同而不同； X 射线衍射物相分析结果表明，形成ΔC 的CO2除了由方解石和白云石的分解产生外，还有少量的由未知矿物提供。
토양식변탄산염(?C)시유기화탐적일개중요지표，재유기화탐중득도엄범적사용，병취득료교호적효과。연이유우대?C 적탄원급기구체광물형태상지교소，도치해법재업내존재일정적질의。본문통과대불동지구지표토양양품、해저침적물이급찬정암설양품진행대비분석，연구기탄원、분포특정급광물형태。결과표명，불동화탐양품중?C적함량여소처적지질배경유관，륙지지표토양양품중?C적함량보편교고，기차위해저침적물양품，찬정암설양품중적최저；이찬정암설양품(환원배경)중?C 적δ13C 치비지표토양양품급해저침적물양품(근지표양화배경)도요편경；유차추측형성?C적탄원유무궤、유궤이급혼합원삼충，각충래원적 C 대?C 적공헌인화탐양품소처적지질배경적불동이불동； X 사선연사물상분석결과표명，형성ΔC 적CO2제료유방해석화백운석적분해산생외，환유소량적유미지광물제공。
The soil secondary carbonate (?C) method is a commonly used surface geochemical exploration technique for oil and gas geochemical surveys. However, its application effectiveness is unsatisfactory due to lack of understanding of the carbon source and the mineral morphology of ?C. In this study, the concentration and carbon isotopic composition of ?C in surface soils, offshore sediments, and drilling cuttings from different areas were measured to reveal their carbon sources, distribution characteristics and mineral morphology. The results show that the concentration of?C in different samples is closely related to the depositional environment of these samples. For example, the near-surface soils on land have a relatively higher concentration of?C, followed by the offshore sediments, and the ?C content in drilling cuttings is the lowest. While theδ13C values of ?C in drilling cuttings are generally more negative than those in near-surface soils and offshore sediments. These results further indicate that the carbons formed?C in different samples may have three sources, including inorganic, organic and mixed sources, and the contributions of different carbon sources are also depended on the depositional environment of samples. The result of X-ray diffraction and phase analysis of some typical samples shows that the CO2 released by pyrolysis is mainly derived from the decomposition of calcite and dolomite in samples, and a small amount provided by some unknown minerals.