CAJ | 학술논문

针对准噶尔盆地南缘古近系和新近系碎屑岩沉积体,运用野外露头宏观分析与岩心、薄片微观描述来 "定岩相和沉积相";依据地震相的不同特点及相变的不同位置,刻画湖岸线演化,从而对沉积体"定边界";根据重矿物组合特征及砂岩等厚图来"定主次物源"的方法,综合研究前陆盆地的沉积相特征.在此基础上,分析了准噶尔盆地南缘湖盆沉积格局与演变,认为准噶尔盆地南缘古近系紫泥泉子组沉积时期,湖平面较低,天山山前带发育4个规模较大的扇三角洲朵状体;至安集海河组沉积时期,湖平面上升,山前带扇三角洲发生退积,仅沉积3个规模变小的朵状体,霍尔果斯地区扇三角洲朵状体不发育.新近系沙湾组沉积时期,由于逆冲推覆构造作用,山前带地形高差大、坡度陡且气候干旱,随着湖平面的迅速下降,山前带发育更大规模进积型扇三角洲沉积.准噶尔盆地南缘古近系-新近系2个主要物源分别是中部东湾-吐谷鲁-玛纳斯背斜、西部西湖-独山子背斜;2个次要物源分别为东部呼图壁背斜和中西部霍尔果斯背斜,此4个物源流向是由南向北.北部卡因迪克地区则是来自前陆隆起区的重要物源.
침대준갈이분지남연고근계화신근계쇄설암침적체,운용야외로두굉관분석여암심、박편미관묘술래 "정암상화침적상";의거지진상적불동특점급상변적불동위치,각화호안선연화,종이대침적체"정변계";근거중광물조합특정급사암등후도래"정주차물원"적방법,종합연구전륙분지적침적상특정.재차기출상,분석료준갈이분지남연호분침적격국여연변,인위준갈이분지남연고근계자니천자조침적시기,호평면교저,천산산전대발육4개규모교대적선삼각주타상체;지안집해하조침적시기,호평면상승,산전대선삼각주발생퇴적,부침적3개규모변소적타상체,곽이과사지구선삼각주타상체불발육.신근계사만조침적시기,유우역충추복구조작용,산전대지형고차대、파도두차기후간한,수착호평면적신속하강,산전대발육경대규모진적형선삼각주침적.준갈이분지남연고근계-신근계2개주요물원분별시중부동만-토곡로-마납사배사、서부서호-독산자배사;2개차요물원분별위동부호도벽배사화중서부곽이과사배사,차4개물원류향시유남향북.북부잡인적극지구칙시래자전륙륭기구적중요물원.
Good ways are found in studying clastic deposits of the Paleogene and Neogene in southern margin of Junggar Basin.The ways are ① Lithofacies and sedimentary facies are distinguished by outcrop analyses and core and thin section description,② The boundaries of deposits are identified by recognition of shoreline evolution according to different characteristics of seismic facies and different locations of facies change and ③ The main and minor provenances are distinguished by characteristics of heavy mineral assemblages and isopach maps of sandstones.Characteristics of sedimentary facies have been studied by this comprehensive method.The depositional framework and evolution of the southern margin of Junggar Basin were analyzed on this basis.The results indicate that during the deposition of the Paleogene Ziniquanzi Formation, 4 large scale fan delta deposits were developed in thrust belt of the Tianshan Mountains and the lake level was lower.During the deposition of the Anjihaihe Formation, 3 fan delta deposits with decreasing sizes were developed in front of the Tianshan Mountains due to the lake level rising and the fan delta retrogration.Fan delta was not developed in Huoerguosi area.During the deposition of the Early Neogene Shawan Formation, fan deltas with larger scales were developed in front of the Mountains, the topography differences were large, the slope was steep and the climate was arid due to lake level quick falling.There are 2 main sedimentary provenances and 2 minor ones from the Paleogene to Neogene in southern margin of Junggar Basin.The main provenances are the Dongwan-Tugulu-Manas anticline in central area, the Xihu-Dushanzi anticline in western area.The minor sedimentary provenances are respectively the Hutubi anticline in eastern area and the Huoerguosi anticline in central western area.These four provenances are distributed in south-north direction.There is a very important provenance in Kayindike area which is from the foreland uplifting area.