CAJ | 학술논문

缅甸 D 区块是伊洛瓦底盆地中西部与 Letpanto 油田相邻的区块，具有一定的油气勘探潜力，对物源方向的认识存在不同观点。笔者利用沉积物砾石成分、砂岩骨架成分、地球化学元素分析方法，旨在明确伊洛瓦底盆地 D 区块及周缘古近纪物源方向和类型，进而指导本区沉积相与油气资源勘探研究。砾石分析结果显示，存在自西向东方向的物源，古新世物源来自中、酸性火成岩，始新世来自浅变质岩、中性及基性火成岩。砂岩骨架成分分析显示，古近纪地层物源均来自弧造山带，既有大陆切割、未切割、过渡型岛弧来源，也有再旋回造山带来源。主量、微量、稀土元素分析结果判断物源区构造背景均属于大陆岛弧和主动大陆边缘，具有安山岩物源区特征。综合分析认为，本区古近纪物源演化具有一定继承和相似性，物源主要来自盆内链状岛弧和东部掸邦高地，喜马拉雅造山带不可能从北部直接提供物源。推测北部喜马拉雅造山带通过伊洛瓦底江从东部进入，为盆地提供物源。
면전 D 구괴시이락와저분지중서부여 Letpanto 유전상린적구괴，구유일정적유기감탐잠력，대물원방향적인식존재불동관점。필자이용침적물력석성분、사암골가성분、지구화학원소분석방법，지재명학이락와저분지 D 구괴급주연고근기물원방향화류형，진이지도본구침적상여유기자원감탐연구。력석분석결과현시，존재자서향동방향적물원，고신세물원래자중、산성화성암，시신세래자천변질암、중성급기성화성암。사암골가성분분석현시，고근기지층물원균래자호조산대，기유대륙절할、미절할、과도형도호래원，야유재선회조산대래원。주량、미량、희토원소분석결과판단물원구구조배경균속우대륙도호화주동대륙변연，구유안산암물원구특정。종합분석인위，본구고근기물원연화구유일정계승화상사성，물원주요래자분내련상도호화동부탄방고지，희마랍아조산대불가능종북부직접제공물원。추측북부희마랍아조산대통과이락와저강종동부진입，위분지제공물원。
Myanmar block D located in the midwest of the Irrawaddy basin,adjacent to Letpanto field,has a certain prospect of oil.There are many different views on provenance of sedimentary among previous study results.Our aims are to make clear the direction and type of the Palaeogene provenance of the block D and the Periheral in the Irrawaddy basin,then to guide the research on facies and the oil and gas exploration by the analytical method of identification of gravel composition,statistical analysis of sandstone fragment components and the analysis of sedimentary geochemistry.The analysis results of patrtical granularity of the gravels,obtained by optical microsope,suggest that there could be one provenance which is the east of the Irrawaddy basin.The rock source of the Palaeocene was consisted of intermediate and acidic rock,but the Eocene provenance came from epimetamorphic and intermediate-basic rock.The analysis of sand detrital composition statistics revealed that provenance of Paleogene strata was derived from the mixed source,contained recycled orogen and the transitional,dissected and undissected arc.The major element,rare-earth element (REE),trace element geochemical analyses show that tectonic settings are all belong to the continental arc and active continental margin and provenances have andesite characteristic.Conbined with previous analysis,it is concluded that the Palaeogene provenance has certain inheritance and similarity.Provenances were mainly from the chain-like island arc in the basin and the highlands of the Shan Plateau in the eastern of basin.The hypothesis that sediments were directly derived from the Himalayan orogen through the northern of the Irrawaddy basin has been denied by the analysis results.It could be that sediments were provided through Irrawaddy River from the east of the basin into the sedimentary province.