古地理学报2026，Vol.28Issue(3)：865-880,16.DOI:10.7605/gdlxb.2026.006
海陆过渡区交织水动力沉积:以厄瓜多尔奥连特盆地为例
Interwoven hydrodynamic sedimentation in a marine-terrestrial transition zone:a case study of the Oriente Basin,Ecuador
摘要
Abstract
The transitional zone between land and sea is an area where rivers,waves and tides act together,and the interwoven hydrodynamic forces shape the sand body morphology and palaeogeographic pattern.This paper takes the Main-Mi member and LU sub-member of the oil and gas-rich Napo Formation in the Oriente Basin of Ecuador as an example.By using core,logging and mud logging data,the sequence framework is established.Provenance was constrained using heavy-mineral assemblages and detrital zircon U-Pb geochronology,while pre-depositional palaeogeomorphology was restored using residual-thickness and imprint methods.The study shows that the Napo Formation can be divided into one second-order sequence and five third-order sequences.The Main-Mi member and LU sub-member are both in the lowstand systems tract of their respective third-order sequences.The provenance mainly comes from the eastern and southeastern Amazon Craton,and the palaeogeomorphology is generally a single inclined slope with the east high and the west low.The LU sub-member is an intertidal delta system controlled by rivers and tides as a whole,with a delta plain in the east and a delta front in the west.The Main-Mi member has evolved into a mixed system of east tidal delta,west wave-controlled shallow marine shelf and coastal current interwoven transformation.The Napo Formation records the evolution process from the river-tide inter-control to the river-wave-tide ternary mixed system,indicating that under the constraints of tectonic subsidence and provenance conditions,the interwoven hydrodynamic forces are the key factors controlling the distribution of sand bodies and palaeogeographic patterns in the transitional zone between land and sea in the foreland basin.This has reference significance for the palaeogeographic restoration of similar transitional zones between land and sea in foreland basins.关键词
交织水动力/海陆过渡区/潮汐三角洲/古地理演化/上白垩统/奥连特盆地Key words
interwoven hydrodynamic forces/transitional zone between land and sea/tidal delta/palaeogeographic evolution/Upper Cretaceous/Oriente Basin分类
天文与地球科学引用本文复制引用
鲍志东,刘维则,张淘,郭妍晶,胡小龙,岳彩新,王腾宇,班舒悦,李发有,王光付,宋逸婷,张辛雨,夏昌盛,欧长健..海陆过渡区交织水动力沉积:以厄瓜多尔奥连特盆地为例[J].古地理学报,2026,28(3):865-880,16.基金项目
国家科技重大专项(编号:2024ZD1003604)和国家重点研发计划项目(编号:2017YFC0603104,2018YFC0604304)联合资助.[Co-funded by the National Science and Technology Major Project(No.2024ZD1003604)and the National Key Research and Development Program of China(Nos.2017YFC0603104,2018YFC0604304)] （编号:2024ZD1003604）
