Spatio-temporal trends in normal-fault segmentation recorded by low-temperature thermochronology: Livingstone fault scarp, Malawi Rift, East African Rift System
Spatio-temporal trends in normal-fault segmentation recorded by low-temperature thermochronology: Livingstone fault scarp, Malawi Rift, East African Rift System
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低温热年代学记录的正断层分割的时空趋势：利文斯通断层陡坎、马拉维裂谷、东非裂谷系统
DOI：
10.1016/j.epsl.2016.08.040
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发表时间：
2016
影响因子：
5.3
通讯作者：
Mortimer E
中科院分区：
文献类型：
--
作者：
Mortimer E
贯穿的正断层阵列从初始成核到生长以及随后的相互作用和机械联系的演化在许多伸展区都有很好的记录。随着时间的推移，这些过程导致可预测的空间和时间变化的位移量和速度积累沿着走向的个别断层段，这应该表现在模式的下盘折返。在这里，我们调查了沿走向和垂直分布的低温磷灰石（U-Th）/He（AHe）冷却年龄沿着边界断层系统，利文斯通断层，位于马拉维裂谷北方的卡隆加盆地。断层的演变和联系，从裂谷开始到现在的一天，以前已通过调查的上盘盆地填充约束。利文斯通断层下盘的新冷却年龄与相邻沉积中心的演化有关，并跨越两个古断层段之间的中继带。我们的数据得到了发表的磷灰石裂变径迹（AFT）数据的补充，并揭示了岩石冷却历史沿走向的显着变化：下盘的中心比现在链接的早期断层段的前尖端产生更年轻的冷却年龄。这表明，低温热年代学可以检测断层相互作用沿着走向。这些前段的边界被保留在挖出的下盘岩石是一个功能的相对较新的链接system.Our研究强调，在AHe（和潜在的AFT）年龄的变化与沿走向位移剖面可以发生在相对较短的水平距离（几公里）。这是非常重要的，在伸展系统的下盘的垂直冷却历史的评估：在一个给定的位置沿着断层走向的构造驱动的折返率的时间差异可能是更重要的控制比通常调用的气候波动的垂直折返率的变化。
The evolution of through-going normal-fault arrays from initial nucleation to growth and subsequent interaction and mechanical linkage is well documented in many extensional provinces. Over time, these processes lead to predictable spatial and temporal variations in the amount and rate of displacement accumulated along strike of individual fault segments, which should be manifested in the patterns of footwall exhumation.Here, we investigate the along-strike and vertical distribution of low-temperature apatite (U–Th)/He (AHe) cooling ages along the bounding fault system, the Livingstone fault, of the Karonga Basin of the northern Malawi Rift. The fault evolution and linkage from rift initiation to the present day has been previously constrained through investigations of the hanging wall basin fill. The new cooling ages from the footwall of the Livingstone fault can be related to the adjacent depocentre evolution and across a relay zone between two palaeo-fault segments. Our data are complimented by published apatite fission-track (AFT) data and reveal significant variation in rock cooling history along-strike: the centre of the footwall yields younger cooling ages than the former tips of earlier fault segments that are now linked. This suggests that low-temperature thermochronology can detect fault interactions along strike. That these former segment boundaries are preserved within exhumed footwall rocks is a function of the relatively recent linkage of the system.Our study highlights that changes in AHe (and potentially AFT) ages associated with the along-strike displacement profile can occur over relatively short horizontal distances (of a few kilometres). This is fundamentally important in the assessment of the vertical cooling history of footwalls in extensional systems: temporal differences in the rate of tectonically driven exhumation at a given location along fault strike may be of greater importance in controlling changes in rates of vertical exhumation than commonly invoked climatic fluctuations.
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DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
A. Miall
通讯作者：
A. Miall
影响因子：
18.3
作者：
E. Roberts;N. Stevens;P. O’Connor;P. Dirks;M. Gottfried;W. Clyde;R. Armstrong;A. Kemp;S. Hemming
通讯作者：
E. Roberts;N. Stevens;P. O’Connor;P. Dirks;M. Gottfried;W. Clyde;R. Armstrong;A. Kemp;S. Hemming
东非裂谷的火山活动告诉我们其演化和动态：重新评估
DOI：
--
发表时间：
2015
期刊：
影响因子：
--
作者：
L. Michon
通讯作者：
L. Michon
DOI：
--
发表时间：
1978
期刊：
Geological Society Special Publication
影响因子：
--
作者：
R. Shackleton
通讯作者：
R. Shackleton
肯尼亚北部裂谷的构造演化
影响因子：
2.7
作者：
C. Morley;W. A. Wescott;D. M. Stone;R. M. Harper;S. Wigger;F. Karanja
通讯作者：
F. Karanja