Eogenetic karstification in carbonatite and its significance for hydrocarbon geology
DAN Yong
LIANG Bin
CAO Jian-wen
ZHANG Qing-yu
HAO Yan-zhen
LI Jing-rui
Abstract：Solution caves or big karst caves can be generated in carbonatite by eogenetic karstification,which is very important for the study of distribution and genesis of such caves in karst areas of the Tarim and Si-chuan basins.However,young carbonate karst is few in amount and poorly studied in China.So,a large number of foreign literature about this issue were collected and reviewed in this paper.The purpose is to present features of the caves by eogenetic karst and their corrosion mechanism,and the petroleum geological significance.(1)Young carbonatite is characterized poor cementation,loose structure,and high porosity and permeability,with uniform medium space.(2)Eogenetic karst is obviously associated with rise and fall of sea level.Especially in islands or coastal areas with fresh-salt water interaction zones,the karstification fea-tured by mixed water is relatively intense.(3)Holes or caves which formed by eogenetic karst have such patterns that flank margin caves develop in islands while channels of mixed zones appear in coastal karst.(4) Development of karst caves depends on the CO 2 content of the freshwater,hydrological power of the mixed transition zone,and the change rate of sea level.(5 )Eogenetic karst provides a theoretical reference for studying the short-term exposure of karstification during geological times.Such research will help under-stand formation mechanisms of hole-cave type carbonate reservoirs in internal karst areas and guide the dis-tribution prediction of hole-cave type reservoirs in carbonatite regions.
Keywords：mixed karstisland karstcoastal karsttelogenetic karstinternal karstflank margin cavesi-chuan basintarim basin
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 126-135,158 )