Middle Miocene (∼14 Ma) and Late Miocene (∼6 Ma) Paleogeographic Boundary Conditions
Middle Miocene (∼14 Ma) and Late Miocene (∼6 Ma) Paleogeographic Boundary Conditions
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DOI：
10.1029/2021pa004298
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发表时间：
2021-11-01
影响因子：
3.5
通讯作者：
Deng, Chenglong
中科院分区：
文献类型：
--
作者：
He, Zhilin;Zhang, Zhongshi;Deng, Chenglong
在中新世，主要的全球冷却发生在两个时间段：中新世中期（类似于14-13 Ma）和中新世晚期（类似于7-6 Ma）。南极冰盖在大约14-13 Ma大幅度扩张，北方半球的冰川作用在大约7-6 Ma开始。虽然这两次全球变冷事件的成因尚不清楚，但古气候模拟为研究其机制提供了重要途径。然而，古气候建模依赖于古地理边界条件，许多不确定性仍然存在关于中新世的陆海分布，地形和水深;特别是，以前发表的中新世中期和晚期的古地理重建显示出一些差异。在这里，我们提出了两套新的全球地形和测深边界条件中中新世（类似于14马）和晚中新世（类似于6马）。我们的新重建使用已发表的板块运动学模型，海洋岩石圈古年龄和海洋沉积物厚度，并结合全球化石记录，地层，岩相，古环境和古海拔数据。利用这些数据，我们进一步约束了欧亚大陆和北极周边几个重要的陆间海和边缘海的条件，北方半球热带和中高纬主要航道的深度，以及全球古地形，特别是青藏高原和安第斯山脉的古地形。
During the Miocene, major global cooling occurred during two intervals: the middle Miocene (similar to 14-13 Ma) and the late Miocene (similar to 7-6 Ma). The Antarctic Ice Sheet expanded substantially at similar to 14-13 Ma, and glaciation in the Northern Hemisphere was initiated at similar to 7-6 Ma. Although the causes of these two global cooling events remain unclear, paleoclimate modeling provides an important approach for investigating the mechanisms. However, paleoclimate modeling relies on paleogeographic boundary conditions, and many uncertainties remain regarding the land-sea distribution, topography, and bathymetry of the Miocene; specifically, previous published paleogeographic reconstructions for the middle and late Miocene show several discrepancies with each other. Here, we present two new sets of global topographic and bathymetric boundary conditions for the middle Miocene (similar to 14 Ma) and late Miocene (similar to 6 Ma). Our new reconstructions use a published plate kinematics model, oceanic lithospheric paleo-ages, and oceanic sediment thicknesses and incorporate global fossil records, stratigraphy, lithofacies, paleoenvironment, and paleoelevation data. With these data, we further constrain the conditions of several important intercontinental and marginal seas surrounding Eurasia and the Arctic, the depth of major seaways in tropical latitudes and middle-high latitudes of the Northern Hemisphere, and global paleotopography, especially that of the Tibetan Plateau and the Andes.