海南省FS凹陷涠洲组和流沙港组石英、长石埋藏成岩作用的初步研究

BURIED DIAGENESIS OF QUARTZ AND FELDSPAR IN WEIZHOU GROUP AND LIUSHAGANG GROUP,FS DEPRESSION, HAINAN PROVINCE

沉积物中被认为最稳定的碎屑组分石英、长石经历了埋藏成岩作用后变得不那么稳定。主要表现为石英、长石在埋藏成岩过程中的溶解(蚀)作用和沉淀作用(再生长)。本文通过对海南省FS凹陷的下第三系涠洲组、流沙港组的研究认为:埋藏的温度和压力是外因,碎屑矿物的成分和孔隙流体的组分是内因。主要从碎屑矿物的成分、孔隙流体的组分(包括pH值)和热动力等方面对该凹陷的石英、长石的成岩作用进行论述和探讨。

Quartz and feldspar, considered as the most stable clastics in sediments become less stable after buried diagenesis. Solution (alteration) and perciptation (regrouth) of these rock minerals are abserved mainly. After an abservation and a study of the lower Tertiery Weizhou Group and Liushagang Group, the authors realize that compositions of these rock minerals and those of the pore fluids are the inner cause while temperature and pressure after burial are the outer causes of such changes. This paper gives a discussion on the diagenesis of quartz and feldspar in this depression in a view of the mineral composition of these clastics, composition of pore fluids (including their pH values) and thermodynamics.