The retroarc Amazon region of Ecuador recorded distinct events that are preserved in the Mesozoic-Cenozoic sedimentary record of the Subandean Zone and Oriente Basin. In this contribution, we review the Jurassic to Paleocene geologic and paleogeographic evolution of the Ecuadorian foreland using stratigraphic, sedimentologic, provenance, and geochronological data. Our results provide new insights into the sedimentary systems, stratigraphic framework, depositional ages, and sediment dispersal patterns of retroarc basin fill.

During the Early Jurassic, marine deposits of the Santiago Formation formed a carbonate platform in eastern Ecuador. At ~180 Ma, an eastward-prograding deltaic system transported volcaniclastic material from a western volcanic arc. Nonmarine conditions prevailed during most of the Middle to Late Jurassic, characterized by deposition of red beds and intercalated volcanic and volcaniclastic deposits of the Chapiza Formation. Clastic and volcanic deposition dated from ~160 to 130 Ma was coeval with regional extension, as suggested by sedimentologic and seismic data from the Oriente Basin.

Provenance results show that a ~ 120 Ma fluvial system at the base of the Hollín Formation was initially sourced from the west and progressively evolved to a mixed source with contributions from the Amazonian Craton and incipient Andean topography. Deposition of the Hollín Formation occurred in a northwest-flowing fluvial system that evolved into an estuary system confined by the Andes to the west and the Amazonian Craton to the east.

Coastal to shallow marine deposits of the Napo Formation accumulated during regional sea-level variations throughout the Late Cretaceous. The geometry of coastal deposits and supporting provenance data suggest a drainage system characterized by west-flowing rivers derived chiefly from the Amazonian Craton.

The latest Cretaceous (~70 Ma) onset of shortening in the Northern Andes coincided with collision of the Caribbean Plateau. This tectonic episode induced a continental-scale drainage reorganization documented in provenance data showing an Andean origin of the east-directed fluvial deposits of the Maastrichtian–Paleocene Tena Formation.

厄瓜多尔的弧后亚马逊地区记录了不同的事件，这些事件保存在苏班德带和东方盆地的中新生代沉积记录中。在这篇文章中，我们使用地层学、沉积学、来源和地质年代学数据回顾了厄瓜多尔前陆从侏罗纪到古新世的地质和古地理演化。我们的研究结果为弧后盆地充填的沉积系统、地层格架、沉积时代和沉积物扩散模式提供了新的见解。

在早侏罗世，圣地亚哥组的海相沉积物在厄瓜多尔东部形成了碳酸盐台地。在~180 Ma，一个东进的三角洲系统从西部火山弧输送火山碎屑物质。中侏罗世至晚侏罗世的大部分时间为非海相条件，其特征是红层沉积以及恰比萨组火山和火山碎屑沉积物的夹层沉积。奥连特盆地的沉积学和地震数据表明，约 160 至 130 Ma 的碎屑岩和火山沉积与区域延伸同时期。

物源研究结果表明，Hollín 组底部的一个约 120 Ma 河流系统最初来自西部，并逐渐演变为混合源，受亚马逊克拉通和初期安第斯地形的影响。霍林组的沉积发生在一个向西北流动的河流系统中，该系统演变成一个河口系统，西部是安第斯山脉，东部是亚马逊克拉通。

在整个晚白垩世区域海平面变化期间积累的 Napo 组沿海至浅海沉积物。沿海沉积物的几何形状和支持的来源数据表明排水系统的特征是主要来自亚马逊克拉通的西流河流。

北安第斯山脉最晚的白垩纪（~70 Ma）开始缩短，恰逢加勒比高原的碰撞。这一构造事件引发了大陆尺度的排水系统重组，来源数据显示马斯特里赫特-古新世 Tena 地层向东的河流沉积物起源于安第斯山脉。