Tectonics and Global Change: inferences from the Late Cenozoic subsidence and uplift patterns in the Atlantic/ Mediterranean region
Tectonics and Global Change: inferences from the Late Cenozoic subsidence and uplift patterns in the Atlantic/ Mediterranean region
复制标题
构造与全球变化：大西洋/地中海地区晚新生代沉降和隆起模式的推论
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
H. Kooi
中科院分区：
文献类型：
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作者：
S. Cloetingh;H. Kooi
摘要
对北大西洋/地中海地区许多裂谷盆地的定量沉降分析为普里奥第四纪沉降的快速阶段提供了证据。观测到的构造沉降加速发生在这些盆地沉降的总体静止阶段之后，并且偏离了拉伸模型的预测。后者表明中生代-第三纪盆地形成后沉降随时间的推移而衰减，而上里奥-第四纪则缓慢的构造沉降。对观察到的异常沉降模式的一个可能解释是北大西洋地区板内压缩水平的增加。上皮里奥-第四纪的板内应力变化与非洲/欧亚大陆碰撞过程的动态以及大西洋扩散方向的重组有关，可能反映了全球性质的板块重组。
普里奥-第四纪记录似乎反映了新构造活动水平增加的时期，与冰川（消）期相互作用。大陆边缘陆上部分的应力引起的地形，加上盆地近海更深部分的应力引起的沉降，可能促成了芬诺斯坎迪亚最近阶段的隆起，从而增强了冰川卸荷引起的隆起。冰厚度的估计是直接从观测到的隆起推断出来的，忽略了其他驱动机制，而地形在冰川动力学中起着至关重要的作用。因此，量化普里奥-第四纪期间快速构造隆起和沉降阶段与气候影响的相互作用非常重要。
SUMMARY
Quantitative subsidence analysis for a number of rifted basins in the northern Atlantic/Mediterranean region provides evidence for rapid phases of PlioQuaternary subsidence. The observed acceleration in tectonic subsidence occurs after a phase of general quiescence in subsidence in these basins and deviates from predictions of stretching models. The latter indicate a decay of subsidence with time after Mesozoic-Tertiary basin formatioh and a slow tectonic subsidence in Plio-Quaternary times. A possible explanation for the observed patterns of anomalous subsidence could be an increase in the level of intraplate compression in the northern Atlantic region. Intraplate stress changes in the Plio-Quaternary are related to the dynamics of African/ Eurasian collision processes and a reorganization of spreading directions in the AtlAntic, possibly reflecting a plate reorganization of global nature.
It seems that the Plio-Quaternary record reflects a period of increased levels of neotectonic activity, interplaying with periods of (de)glaciation. Stress-induced topography in the onshore parts of continental margins, coupled with the stress-induced subsidence in the offshore deeper parts of the basins, could have contributed to recent phases of uplift in Fennoscandia, augmenting the uplift induced by glacial unloading. Estimates of ice thicknesses are directly inferred from the observed uplift ignoring other driving mechanisms whereas topography plays a crucial role in the dynamics of glaciation. It is, therefore, important to quantdy the interplay of rapid tectonic uplift and subsidence phases with climatic effects during the Plio-Quaternary.