加里曼丹岛南缘中中新世沉积特征及其主控因素探讨

Middle Miocene Sedimentary Characteristics and Main Controlling Factors in the Southern Margin of Kalimantan Island

加里曼丹岛地处东南亚区域中心位置,新生代以来其最显著的构造特征是伴随东南亚板块构造运动经历了逆时针旋转过程。重点针对中新世时期东南亚区域大规模构造事件,开展区域构造—沉积响应特征研究。基于加里曼丹岛东南部库泰盆地中新世三角洲沉积体系特征研究成果,结合加里曼丹岛南部东爪哇盆地中新世半深海斜坡—盆底沉积体系特征分析,综合探讨加里曼丹岛南缘中新世区域构造反转—沉积响应特征。中中新世时期15 Ma左右,形成了大规模马哈坎进积型三角洲沉积体系雏形;依据钻井与地震数据约束,推断东爪哇盆地中新世半深海斜坡—盆底沉积体系初始发育时间为16~15 Ma,2种沉积体系初始发育时间基本一致。推断东南亚区域中中新世时期大规模构造反转事件是加里曼丹岛南缘2种沉积体系发育的主要控制因素;而同时期库泰盆地开阔深水环境和东爪哇盆地东西向狭长延伸半深海环境,分别为库泰盆地大规模进积型三角洲沉积体系和东爪哇盆地半深海浊积体发育创造了充足的可容纳空间。

Kalimantan Island is located in central Southeast Asia.Since the Cenozoic,the most significant tectonic feature of Kalimantan Island has been that it experienced counter-clockwise rotation as a result of plate tectonic movement in Southeast Asia.This study focuses on the regional tectonic-sedimentary response characteristics of large-scale tectonic events in Southeast Asia during the Miocene.Based on a systematic review of the characteristics of the Miocene delta sedimentary system in the Kutei Basin(Southeast Kalimantan Island),and the analysis of the characteristics of the Miocene semi-deep bathyal slope and basin floor sedimentary system in the East Java Basin(South Kalimantan Island),this paper comprehensively discusses the characteristics and sedimentary response to the Miocene regional tectonic inversion in the southern margin of Kalimantan Island.Approximately 15 Ma during the Middle Miocene,a large-scale Mahakan progressive delta depositional system was formed.According to the drilling and seismic data constraints,the initial development time of the Miocene semi-deep bathyal slope and basin-floor sedimentary system in the East Java Basin is approximately 16-15 Ma.The initial development times of the two sedimentary systems were similar.The paper holds that the large-scale tectonic inversion events during the Middle Miocene in Southeast Asia are the main controlling factors for the development of the two sedimentary systems in the southern margin of Kalimantan Island.In the same period,the open deep-water environment of the Kutei Basin and the East-West narrow extended semi-deep bathyal environment of the East Java Basin created sufficient space for the development of a large-scale progradational delta sedimentary system in the Kutei Basin and semi-deep bathyal turbidite in the East Java Basin.