Marine palynological record for tropical climate variations since the late last glacial maximum in the northern South China Sea
Marine palynological record for tropical climate variations since the late last glacial maximum in the northern South China Sea
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南海北部末次盛冰期晚期以来热带气候变化的海洋孢粉学记录
DOI：
10.1016/j.dsr2.2015.06.011
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发表时间：
2015-12-01
影响因子：
3
通讯作者：
Weng, Chengyu
中科院分区：
文献类型：
--
作者：
Dai, Lu;Weng, Chengyu
对南海北方MD 05 -2906柱状沉积物上部（191-1439 cm）进行了孢粉学研究。年代学表明，它涵盖了类似于19万年前（cal ka BP）以来的记录，并揭示了自末次盛冰期（LGM）以来的详细环境变化历史。在末次盛冰期晚期，由于海平面下降（约100 m），从海岸到研究地点的距离缩短，花粉浓度非常高。在15 cal ka BP之前，花粉组合以非木本植物为主，尤其是蒿属花粉。丰富的亚热带和热带花粉类群仍然是重要组成部分，南亚热带气候占主导地位的晚期LGM。同时存在的丰富蒿属花粉可能不是来自近岸，而主要来自东海北方裸露陆架。在近似15 cal ka BP之后，随着海平面的上升和距花粉源区距离的增大，花粉浓度开始逐渐下降。然而，在冰消期晚期和全新世早期，许多花粉类群的高浓度再次出现，这不能归因于海平面的变化。沉积在岩芯中的松花粉，根据许多现代花粉调查，被认为主要是水携带的，也开始急剧增加。因此，较高的花粉浓度，更多的松和香蒲（水生植物）花粉表明，显着增强的陆地径流和降水在末次冰消期/全新世过渡（类似于11.3-9.4 cal ka BP）。我们推测，一个强大的夏季风发生在这个时候。在末次盛冰期晚期/冰消期的过渡期，花粉组合反映了逐渐变暖的气候，来自高纬度的气候波动没有得到很好的识别。太阳辐射对南海北方的东亚季风和水文循环具有重要的控制作用。(C)2015爱思唯尔有限公司版权所有。
The upper part (191-1439 cm) of the marine sediment core MD05-2906 from the northern South China Sea (SCS) was palynologically investigated. The chronology suggested that it covered the record since similar to 19 calendar kiloyears before present (cal ka BP) and revealed a detailed environmental change history since the late last glacial maximum (LGM). During the late LGM, due to the lowered sea level (similar to 100 m lower) and the shortened distance from the shore to the study site, the pollen concentration was very high. The pollen assemblages were dominated by non-arboreal taxa, especially Artemisia pollen, before similar to 15 cal ka BP. Abundant subtropical and tropical pollen taxa were still important components and a south subtropical climate prevailed during the late LGM. The coexistent rich Artemisia pollen possibly was not derived from near shores, but was derived mainly from the northern exposed continental shelf in the East China Sea (ECS). After similar to 15 cal ka BP, with the rise in the sea level and enhanced distance from the pollen source areas to the core site, pollen concentrations started to decline gradually. However, during the late deglaciation and early Holocene, the higher concentrations of many pollen taxa reoccurred, which cannot be attributed to the sea level changes. Pinus pollen deposited in the core, which is considered to be mostly water-carried based on many modern pollen surveys, also started to dramatically increase at the same time. Therefore, the higher pollen concentration, with more Pinus and Typha (an aquatic plant) pollen indicated a notably enhanced terrestrial runoff and precipitation during the last deglaciation/Holocene transition (similar to 11.3-9.4 cal ka BP). We inferred that a strong summer monsoon occurred at this time. During the late LGM/deglaciation transition period, the pollen assemblage reflected a gradually warming climate, and the climate fluctuations derived from the high-latitudes were not well-identified. This study suggests that solar insolation played a crucial role in controlling the East Asian monsoon and hydrological cycle in the northern SCS. (C) 2015 Elsevier Ltd. All rights reserved.