Late Pleistocene to Holocene formation process of Mekong River Delta, South Vietnam

南越湄公河三角洲晚更新世至全新世形成过程

• 批准号: 12440133
• 负责人: TATEISHI Masaaki
• 金额: $ 8.7万
• 依托单位: Niigata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12440133/
• 关键词: Mekong River Delta; Strand Plain; Coastal dune; 14C age; OSL dating; Facies Analysis; Delta progradation; Tide and wave mixed delta; 砂丘砂; 鉱物組成; 音響探査; 不整合; 完新統; プログラデーション; 浜提列; デルタフロント; 堆積相; 海水準変動; 環境変遷; 相対的海水準変動; 沿岸成層

Detail analysis of core samples from 11 bore holes in the Lower Mekong River Delta show the sedimentation during the postglacial transgression and the Holocene evolution of the Mekong River Delta. The incised valley that formed during LGM (the Last Glacial Maximum) was mostly filled during the rise of sca-level after the LGM. The interfluvial zones are about -20 m in altitude and are covered unconformably by Holocene deltaic sediments. The deltaic sediments and detailed chlonostratigraphic analyses clearly show the delta progradation for the last 4 kyr in terms of the sediment facies, tide influence, progradation rate, and subaerial and subaqueous topography. As the delta has evolved, the delta environment has become more wave-influenced with the development of a beach-ridge field, longshore sediment dispersal, and a steep face of the delta front. Seismic profiles get by uni-boom along Mekong River and channels show clearly the unconformity within the Upper Pleistocene sediments. The a … More lluvial sediments lying on the unconformity is generally 20 to 40 m in thickness, partly upto 70m in incised valley.Lower part of the Mekong River Delta is topographically characterized by development of several lines of active and relict beach sand ridges. The geomorphologic and sedimentologic features of these active and relict beach ridges were described primarily together with some ages by OSL dating from quartz grains of beach ridges. Samples for sedimento-logic and chlonologic analysis were collected from 8 lines of beach ridges and one boring core. Eight lines of relict and active sand ridges are observed to the south of Tra Vinh City. Although they are arranged generally parallel to the recent river and coast line, are distinctively developed in the eastern side of the island. Especially four lines inland converge to the south of the City, and elongated in the N-S direction parallel to the recent river. All beach ridges are diverged southward and westward to several narrow and low ridges. Some ages are gotten from relict beach sands by OSL dating method. Their ages are classified generally into two groups, that is, sands older than 4 kyr and ones younger than 1.2 kyr. Less

详细分析了湄公河三角洲下游11个钻孔的岩芯样品，揭示了湄公河三角洲在冰后期海侵和全新世演化过程中的沉积作用。在末次盛冰期（LGM）形成的下切谷，在末次盛冰期后的上升期被大部分充填。河间带海拔约-20 m，不整合地被全新世三角洲沉积物覆盖。三角洲沉积物和详细的年代地层分析清楚地表明，三角洲的沉积相，潮汐影响，沉积速率，陆上和水下地形的最后4kyr。随着三角洲的发展，三角洲环境变得越来越受波浪的影响，形成了海滩-山脊场、沿岸沉积物分散和三角洲前缘的陡峭面。沿着湄公河和河道的单杆地震剖面清楚地显示了上更新统沉积物中的不整合面。的a ...更多信息 不整合面上的冲积物厚度一般为20 ~ 40 m，下切谷部分可达70 m，湄公河三角洲下部地形特征为发育多条活动和残留海滩沙脊。初步描述了这些活动和残留海滩脊的地貌和沉积特征，并对海滩脊的石英颗粒进行了光释光测年。从8条海滩山脊线和1个钻孔岩芯中采集了沉积学和岩性分析样品。在茶荣市南部观察到八条残存和活跃的沙脊。虽然它们通常平行于最近的河流和海岸线排列，但在岛的东侧有明显的发展。特别是四条内陆线汇聚到城市南部，并在南北方向平行于最近的河流拉长。所有海滩脊都向南和向西分叉成几个狭窄而低的脊。利用光释光法对残留海滩砂进行了年龄测定。它们的年龄一般分为两组，即4kyr以上的砂和1.2kyr以下的砂。少

项目成果

Susumu Tanabe, Thi Kim Oanh Ta, Van Lap Nguyen, Masaaki Tateishi, Iwao Kobayashi, and Yoshiki Saito: "Delta evolution model inferred from the Holocene Mekong Delta, Southern Vietnam"Society of Economic Paleontologists and Mineralogists, Spec. Pub.. in pre

Susumu Tanabe、Thi Kim Oanh Ta、Van Lap Nguyen、Masaaki Tateishi、Iwao Kobayashi 和 Yoshiki Saito：“从越南南部全新世湄公河三角洲推断的三角洲演化模型”经济古生物学家和矿物学家学会，规范。

Nguyen Van Lap: "Late Holocene depositional environments and coastal evolution of the Mekong River Delta, Southern Vietnam"Journal of Asian Earth Sciences. 18. 427-439 (2000)

Nguyen Van Lap：“越南南部湄公河三角洲晚全新世沉积环境和海岸演化”亚洲地球科学杂志。

Ta Thi Kim Oanh, Nguyen Van Lap, Tateishi Masaaki, Kobayashi Iwao, Saito Yoshiki, and Nakamura Toshio: "Sediment facies and Late Holocene progradation of the Mekong River Delta in Bentre Province, southern Vietnam : an example of evolution from a tide-dom

Ta Thi Kim Oanh、Nguyen Van Lap、Tateishi Masaaki、Kobayashi Iwao、Saito Yoshiki 和 Nakamura Toshio：“越南南部本特雷省湄公河三角洲的沉积相和晚全新世进积：潮汐域演化的一个例子

Ta Thi Kim Oanh: "Sediment facies and Late Holocene progradation of the Mekong River Delta in Bentre Province, southern Vietnam: an example of evolution from a tide-dominated to a tide-and wave-dominated delta"Sedimentary Geology. 152. 313-325 (2002)

Ta Thi Kim Oanh：“越南南部本特雷省湄公河三角洲的沉积相和全新世晚期进积：从潮汐主导型三角洲到潮汐和波浪主导型三角洲演化的一个例子”沉积地质学。

Ta Thi Kim Oanh: "Holocene delta evolution and sediment discharge of the Mekong River, southern Vietnam"Quaternay Science Review. 21. 1807-1819 (2002)

Ta Thi Kim Oanh：“越南南部湄公河全新世三角洲演化和泥沙排放”第四纪科学评论。