石油与天然气地质 ›› 1999, Vol. 20 ›› Issue (2): 144-147.doi: 10.11743/ogg19990211

• 论文 • 上一篇    下一篇

深水碳酸盐岩成岩作用的稳定同位素特征

郭成贤, 王正允, 王方平   

  1. 江汉石油学院, 湖北荆州 434102
  • 收稿日期:1999-03-01 出版日期:1999-06-25 发布日期:2012-01-18

STABLE ISOTOPIC CHARACTERISTICS OF DIAGENESISIN DEEP WATER CARBONATE ROCKS

Guo Chengxian, Wang Zhengyun, Wang Fangping   

  1. Jianghan Petroleum Institute, Jingzhou, Hubei
  • Received:1999-03-01 Online:1999-06-25 Published:2012-01-18

PDF (PC)

1080

被引次数

15

摘要：

稳定同位素方法可以有效地应用于深水碳酸盐岩的成岩作用研究。根据早古生代中扬子台地东南缘斜坡带上碳酸盐岩的氧、碳稳定同位素特征,对几种成岩作用的环境因素和成岩机制进行了研究和探讨:(1)下奥陶统瘤状灰岩瘤体的δ18O值均重于基质,证实了瘤状灰岩的早期雏形是灰泥沉积物经海底溶解 胶结的反复交替作用而形成的;(2)下寒武统厚层状白云岩具有δ18O和δ13C值相对集中,且δ18O略偏负的特点,而下奥陶统层状白云岩的δ18O具有很高的负值,反映了二者分别是高盐度卤水流交代白云岩化和埋藏白云岩化的产物;(3)下奥陶统碳酸盐岩的不同岩石类型或不同结构组分均呈现18O明显亏损,而13C无明显变化的特征,说明受到了较强的埋藏重结晶作用的影响。

关键词: 稳定同位素, 深水碳酸盐岩, 成岩作用, 中扬子台地, 早古生代

Abstract:

Stable isotopic method can be used effectively in the diagenetic research of deep water carbonate rocks.According to the oxygen and carbon isotopic compositions of the Early Palaeozoic deep water carbonate rocks developed along the southeastern marginal slop of the Middle Yangtze carbonate platform,some diagenetic environments and diagenetic mechanisms are as fallowe:1)the δ18O values of nodules of Lower Ordovician nodular limestone are always more positive than those of matrix,suggesting that the prototype of the modular limestone was the product of solution and cementation occurred repeatedly on the sea floor;2)the Lower Cambrian massive dolomite with relatively concentric values of δ18O and δ13C was the product of high density brine replaced dolomitizatin,whereas the lower Ordovician massive dolomite with high negative δ18O value was formed by the deep burial dolomitization;3)Burial recrystallization altered strongly the Lower Ordovician carbonate rocks,and made them to have the same high negative δ18O values.

Key words: stable isotope, deep-water carbonate rock, diagenesis, Middle Yangtze Platform, Early Paleozoic