Recent 200+ km progradation of the Mekong River delta over the last 6000 years has provided a sequence of incised-valley fills with insights into the sedimentary response of a large river system to sea-level changes since the Last Glacial Maximum (LGM). This study provides an analysis of comprehensive synthesis of the incised-valley and successive progradational deposits of the paleo-Mekong River across a regional area spanning from the Cambodian lowland to the Vietnamese shelf. The study is based on the analysis of the depositional facies, diatom and foraminiferal assemblages, and radiocarbon ages of three new cores and previously published cores. The depositional succession observed in these cores is divided into the lower and upper units representing Pleistocene weathered sediment and incised valley fills and delta sediment since the LGM, respectively. The upper unit shows an upward-deepening succession from the fluvial channel to estuary and subtidal deposits, followed by an upward-shallowing succession consisting of progradational deltaic deposits. This unit can be divided into four phases: the fluvial channel sedimentation (before ~13.4 ka); retrogradational and aggradational estuarine system (~13 to ca. 8 ka), aggradational and progradational delta system (ca. 8 to 6 ka), progradational delta system (6 ka to present). Tides were dominant from 13 to ~3.5 ka, followed by wave- and tide-dominated environments until present at its river-mouth and coast.

The data from three new cores, along with existing data, enable paleogeography reconstruction of the incised valley and subsequent delta progradation in four stages at 10, 8, 6, and 4 ka. The results indicate the Mekong River incised valley was ‐−35 to −40.0 m deep and 25 km wide in comparison with surrounding interfluve areas at 6 ka. Additionally, it was filled mostly during transgression from 13 to 8 ka and early highstand periods including its shelf valley beneath the present delta plain, which was filled completely by 4 ka. In the upper delta plain in Vietnam, the succession formed during 8–6 ka appears to have been removed and then deposited by subsequent fluvial channel/tidal river facies dated 4.4 to 2.2 ka.

过去6000年以来，湄公河三角洲最近200多公里的扩建提供了一系列切谷补给，深入洞察了自上次冰河最高峰（LGM）以来大型河流系统对海平面变化的沉积响应。这项研究提供了从柬埔寨低地到越南陆架的整个区域的古湄公河切谷和后续渐进沉积物的综合综合分析。该研究是基于对三个新岩心和以前发表的岩心的沉积相，硅藻和有孔虫组合以及放射性碳年龄的分析。自LGM以来，在这些岩心中观察到的沉积演替分为上下单元，分别代表更新世风化的沉积物，切开的河谷填充物和三角洲沉积物。分别。上部单元显示出从河道到河口和潮间带沉积物的向上加深的演替，随后是由三角洲沉积物组成的向上变浅的演替。该单元可分为四个阶段：河道沉积（〜13.4 ka之前）；河道沉积（约13.4 ka）。逆行和渐进的河口系统（约13至约8 ka），渐进和渐进的三角洲系统（约8至6 ka），渐进的三角洲系统（目前为6 ka）。潮汐从13 ka到〜3.5 ka占主导地位，其次是波浪和潮汐为主的环境，直到其河口和海岸出现为止。该单元可分为四个阶段：河道沉积（〜13.4 ka之前）；河道沉积（约13.4 ka）。逆行和渐进的河口系统（约13至约8 ka），渐进和渐进的三角洲系统（约8至6 ka），渐进的三角洲系统（目前为6 ka）。潮汐从13 ka到〜3.5 ka占主导地位，其次是波浪和潮汐为主的环境，直到其河口和海岸出现为止。该单元可分为四个阶段：河道沉积（〜13.4 ka之前）；河道沉积（约13.4 ka）。逆行和渐进的河口系统（约13至约8 ka），渐进和渐进的三角洲系统（约8至6 ka），渐进的三角洲系统（目前为6 ka）。潮汐从13 ka到〜3.5 ka占主导地位，其次是波浪和潮汐为主的环境，直到其河口和海岸出现为止。

来自三个新岩心的数据以及现有数据可以对切开的山谷进行古地理重建，并随后在10、8、6和4 ka的四个阶段进行三角洲演化。结果表明，与6 ka周围的干扰区相比，湄公河切开的山谷深-35至-40.0 m，宽25 km。此外，它的充填大部分是在海侵13到8 ka以及早期高潮时期，包括它在目前的三角洲平原下方的陆架谷地，该谷底完全被4 ka充满。在越南的上三角洲平原，在8-6 ka形成的演替似乎已被清除，然后由随后的4.4至2.2 ka的河道/潮汐河相沉积。