Late Pleistocene and early Holocene sea-level history and glacial retreat interpreted from shell-bearing marine deposits of southeastern Alaska, USA
Late Pleistocene and early Holocene sea-level history and glacial retreat interpreted from shell-bearing marine deposits of southeastern Alaska, USA
复制标题
DOI：
10.1130/ges02359.1
复制
发表时间：
2021-12-01
期刊：
影响因子：
2.5
通讯作者：
Briner, Jason P.
中科院分区：
文献类型：
--
作者：
Baichtal, James F.;Lesnek, Alia J.;Briner, Jason P.
我们利用整个阿拉斯加东南部（美国）超过720个含壳海洋沉积物的数据集，开发更新的相对海平面曲线，跨越过去14,000年。该数据集包括站点位置，海拔，描述（如可用）和436个C-14年龄，其中45个是首次在这里发布。我们的海平面曲线表明，一个外围的前隆开发西部的退缩科迪勒拉冰盖（CIS）之间的约。17，000和10，800校准年BP，14，870 +/- 630至12，820 +/- 340校准年BP，独联体的边缘已经从阿拉斯加东南部的所有峡湾、海峡和通道撤退。在这个时候，孤立的或搁浅的冰盖存在于岛上，在许多山谷中有高山或冰川。海拔25米的古海岸线标志着研究区域南部海侵的最大高度，这是在11，000 +/- 390至10，500 +/- 420 cal. yr B. P.（Sardinops sagax）和沉积物中丰富的木炭，000 +/- 390和7630 +/- 90 cal. yr B. P.表明阿拉斯加东南部的海洋和空气温度在全新世早期相对温暖。这里提出的海平面和古环境重建可以为未来阿拉斯加东南部冰川，火山和考古历史的调查提供信息。
We leverage a data set of >720 shell-bearing marine deposits throughout southeastern Alaska (USA) to develop updated relative sea-level curves that span the past similar to 14,000 yr. This data set includes site location, elevation, description when available, and 436 C-14 ages, 45 of which are published here for the first time. Our sea-level curves suggest a peripheral forebulge developed west of the retreating Cordilleran Ice Sheet (CIS) margin between ca. 17,000 and 10,800 calibrated yr B.P. By 14,870 +/- 630 to 12,820 +/- 340 cal. yr BP., CIS margins had retreated from all of southeastern Alaska's fjords, channels, and passages. At this time, isolated or stranded ice caps existed on the islands, with alpine or tidewater glaciers in many valleys. Paleoshorelines up to 25 m above sea level mark the maximum elevation of transgression in the southern portion of the study region, which was achieved by 11,000 +/- 390 to 10,500 +/- 420 cal. yr B.P. The presence of Pacific sardine (Sardinops sagax) and the abundance of charcoal in sediments that date between 11,000 +/- 390 and 7630 +/- 90 cal. yr B.P. suggest that both ocean and air temperatures in southeastern Alaska were relatively warm in the early Holocene. The sea-level and paleoenvironmental reconstruction presented here can inform future investigations into the glacial, volcanic, and archaeological history of southeastern Alaska.