矿物共生分析在很低级变质作用研究中的应用——以松潘—阿坝地区红参1井为例

现代地质 ›› 2007, Vol. 21 ›› Issue (3): 457-461.

矿物共生分析在很低级变质作用研究中的应用——以松潘—阿坝地区红参1井为例

汤艳，桑隆康，刘嶸，于吉顺，袁晏明

中国地质大学地球科学学院,湖北武汉430074

收稿日期:2007-01-30 修回日期:2007-06-20 出版日期:2007-03-20 发布日期:2007-03-20
作者简介:汤艳，女，硕士研究生，1983年出生，岩石学、矿物学、矿床学专业，主要从事岩石学与变质地质学的研究。Email：breadwolf@163.com。
基金资助:
中国石油化工股份有限公司科学技术研究项目(G08000-05-ZS-0037)

Application of Mineral Paragenesis Analysis to the Research of Very Low-grade Metamorphism: Taking Well Hongcan No.1 in Songpan-Aba Area as an Example

TANG Yan, SANG Long-kang, LIU Rong, YU Ji-shun, YUAN Yan-ming

Faculty of Earth Sciences, China University of Geosciences, Wuhan, Hubei430074, China

Received:2007-01-30 Revised:2007-06-20 Online:2007-03-20 Published:2007-03-20

摘要/Abstract

摘要：

自1967年Kübler用X射线衍射(XRD)法测量伊利石结晶度以划分极低级变质带以来，伊利石结晶度一直是划分极低级变质带的主要指标。但是不同的人用伊利石结晶度Kübler指数划分变质级的方案不同。因此，尚需要结合岩石学分析方法判定变质级。作为一种尝试，对川西北松潘—阿坝地区红参1井5 975 m深度内的变泥质岩进行了矿物共生分析。结果表明，钻遇地层遭受了高级近变质作用，只是由于岩石化学成分原因，未能出现泥质岩近变质指示矿物黑硬绿泥石，并未达到浅变质级别,不至于破坏油气的保存。Kisch(1990) 提出的变质级划分方案比较符合研究区的实际情况。在极低级变质研究中应用矿物共生分析,一方面可以解决类似的结晶度研究的分歧，另一方面对于指导薄片观察以及X衍射物相分析十分有益。

关键词: 极低级变质作用, 矿物共生分析, 伊利石结晶度, 松潘—阿坝地区

Abstract:

Illite crystallinity has been used as a primary index for subdividing very low-grade metamorphic zone since 1967 after Kübler who measured illite crystallinity by use of XRD and subdivided very low-grade metamorphic zone according to illite crystallinity first. However, Kübler indexes which are used to subdivide metamorphic grade are various among geologists. Therefore a combined research with petrology study is needed in order to solve such dispute. This paper attempts to apply the conventional method of mineral paragenesis analysis to the metapelites in Well Hong-can No.1 in Songpan-Aba area within a depth of 5,975 meters. The result reveals that these rocks have undergone high anchimetamorphism. Stilpnomelane, which is believed as an indicator mineral for anchimetamorphism in metapelite, cannot occur because of the limitation of bulk composition. However, they didn't reach epimetamorphism yet, the preservation of combination gas is still possible. Comparing with petrological evidences, we found the illite crystallinity index scheme proposed by Kisch(1990) is comparatively accorded with the true situation of this area. It is believed that applying mineral paragenesis analysis in the research on very low-grade metamorphism is crucial to solve such index dispute, and moreover, it is very useful for guiding thin section observation and the X-ray diffraction phase analysis.

Key words: very low-grade metamorphism, mineral paragenesis analysis, illite crystallinity, Songpan-Aba area

中图分类号:

P588.3

汤艳，桑隆康，刘嶸，于吉顺，袁晏明. 矿物共生分析在很低级变质作用研究中的应用——以松潘—阿坝地区红参1井为例[J]. 现代地质, 2007, 21(3): 457-461.

TANG Yan, SANG Long-kang, LIU Rong, YU Ji-shun, YUAN Yan-ming. Application of Mineral Paragenesis Analysis to the Research of Very Low-grade Metamorphism: Taking Well Hongcan No.1 in Songpan-Aba Area as an Example[J]. Geoscience, 2007, 21(3): 457-461.