沉积学报2026，Vol.44Issue(2)：481-495,15.DOI:10.14027/j.issn.1000-0550.2024.018
古龙凹陷青山口组页岩中黄铁矿脉与凝灰岩脉特征及成因机制
Characteristics and Genetic Mechanism of Pyrite Dikes and Tuff Dikes in Shale Oil Reservoir of Qingshankou Formation,Gulong Sag
摘要
Abstract
[Objective]By studying the geometric characteristics and formation mechanism of pyrite and tuff dikes in shales of the Qingshankou Formation in Gulong Sag,this paper discusses their formation time,sedimentary environ-ment,sedimentary process,sediment state and diagenetic environment,and estimates the diagenetic compaction rate of shale,which provides reference for the formation mechanism and significance of the same type of dikes.[Methods]Based on detailed core observation,thin section analysis and dynamic calculation of dike formation,pyrite and tuff dikes are found in the Gulong shale,and their genetic mechanism and geological significance are explored.[Results]The pyrite and tuff dikes in shales of the Qingshankou Formation in Gulong Sag are small in scale,and pyrite dikes can be divided into two types according to their scale.One is the thick pyrite dikes with a width of 1-4 mm and a length of several centimeters;The other is a thin pyrite dike,which is less than 1 mm wide and several millimeters to several centimeters long.Tuff dikes are mostly less than 1 mm in width and several millime-ters to several centimeters in length,and most of them are strongly bent into ptygmatite,erect,inclined or horizontally produced.It is speculated that gravity subsidence may be caused by density inversion,and the dynamic formation model of pyrite and tuff dike is established by calculation.[Conclusions]The shape of pyrite dike in shale oil reser-voir of the Qingshankou Formation in Gulong Sag is very complex,which is formed by gravity subsidence sand dike after late pyritization,that is,there are silt dikes first and then pyrite dikes formation.The tuff formed by volcanic eruption settling on unconsolidated mud of lake,and then tuff dike formed due to gravity subsidence caused by density inversion,rather than overpressure filling from bottom to top caused by seismic liquefaction.The oblique py-rite dike and tuff dike are symmetrical at a distance of 180 degrees,which are subjected to bedding shear action.There are many silt-grade mud debris and large flame-like mud debris in the interior dikes,which are formed by the sand dike and tuff dike sinking into the unconsolidated or even muddy mud at the lower part and being captured.关键词
黄铁矿脉/凝灰岩脉/液化/重力坠落/页岩油/古龙凹陷Key words
pyrite dike/tuff dike/liquefaction/gravity fall/shale oil/Gulong Sag分类
天文与地球科学引用本文复制引用
陆加敏,林铁锋,李军辉,付秀丽,苏杨鑫,白月,钟建华,孙宁亮..古龙凹陷青山口组页岩中黄铁矿脉与凝灰岩脉特征及成因机制[J].沉积学报,2026,44(2):481-495,15.基金项目
国家自然科学基金项目(42072138,41572088) （42072138,41572088）
中国石油天然气股份有限公司重大科技专项(2021ZZ10) （2021ZZ10）
黑龙江省"百千万工程"科技重大专项(2020ZX05A01) National Natural Science Foundation of China,No.42072138,41572088 （2020ZX05A01）
Major Science and Technology Projects of China National Pe-troleum Corporation Limited,No.2021ZZ10 （）
"Million and Ten Million"Major Project in Science and Technology,Heilongjiang Pro-vince,No.2020ZX05A01 （）
