CAJ | 학술논문

原生的石膏脉通常呈层、片状分布，在准噶尔盆地南部四棵树河地区野外地质考察中发现有龟壳状结构的石膏脉晶体。通过对周边地区露头实测、探勘、取样及盆地腹部钻井取心资料分析，结合前人研究成果，对龟壳状结构石膏脉形成的古环境背景、盆内沉积证据、龟裂成因和充填石膏成因进行系统研究。准噶尔盆地在三叠-新近纪为内陆浅水湖盆沉积，南部山前地区新近系沙湾组发育辫状河三角洲相和湖泊相，岩相古地理特征受湖平面升降及构造综合控制。研究区发育大量红层沉积，盆地岩石的“先成岩、后胶结”为龟壳状结构石膏脉形成提供了必要条件。综合认为，龟壳状结构石膏脉的形成可能是经“两期盐湖、四个阶段”的作用而成，主要分为一期盐湖作用的原始状态阶段和龟裂状态阶段、二期盐湖作用的龟裂注溶盐水状态和龟裂充填石膏状态。龟壳状结构石膏脉的发现可推测盆地腹部存在天然储层裂缝改造区，为预测有利区带提供地质依据，并对中国西北地区新近纪干旱沉积环境指示具一定参考意义。
원생적석고맥통상정층、편상분포，재준갈이분지남부사과수하지구야외지질고찰중발현유구각상결구적석고맥정체。통과대주변지구로두실측、탐감、취양급분지복부찬정취심자료분석，결합전인연구성과，대구각상결구석고맥형성적고배경배경、분내침적증거、구렬성인화충전석고성인진행계통연구。준갈이분지재삼첩-신근기위내륙천수호분침적，남부산전지구신근계사만조발육변상하삼각주상화호박상，암상고지리특정수호평면승강급구조종합공제。연구구발육대량홍층침적，분지암석적“선성암、후효결”위구각상결구석고맥형성제공료필요조건。종합인위，구각상결구석고맥적형성가능시경“량기염호、사개계단”적작용이성，주요분위일기염호작용적원시상태계단화구렬상태계단、이기염호작용적구렬주용염수상태화구렬충전석고상태。구각상결구석고맥적발현가추측분지복부존재천연저층렬봉개조구，위예측유리구대제공지질의거，병대중국서북지구신근기간한침적배경지시구일정삼고의의。
The primary gypsum veins are usually distributed in layers,but in a recent field geological investigation in SiKeshu river area, gypsum veins with tortoise shell structure have been founded,which are quite rare.On the basis of Measurement,exploration and sampling of surrounding outcrops as well as a detailed analysis of core information from hinterland of basin,combined with early researches,a study is carried out ,which includes setting of paleoenvironment, evidence of sedimentary basin, causes of cracks and causes of filling gypsums. The study shows that Junggar basin is hot and dry during Triassic and Neogene period, which deposits in inland shallow lacurstrine basins. Shawan formation of the pediment region of southern Junggar basin develops braided river delta facies and lacurstrine facies during Neogene period. The paleogeography feature is controlled by fluctuation of lack level and structure. The studying area develops a lot of red layer sediments, cmentation after diagenesis provides a necessary condition for the formation of gypsum veins with tortoise shell structure. The development of gypsum veins with tortoise shell structure in SiKeshu river during Neo-gene period may undergo two stages of salt lack with four periods, and the first stage of salt lake can divided into origi-nal period and crack period, while the second stage of salt lake can divided into crack injection of saline solution period and crack filling gypsum veins period. The finding of fiber gypsum with tortoise shell structure can predict that the cen-tral part of the northern sedimentary area may exist naturally fracture-affected reservoir, thus providing geological proofs for the prediction of favorable zones, in addition,it is a reference for indicting the arid sedimentary environment of tertia-ry strata in northwestern area.