Persistent long-term (c. 24 Ma) exhumation in the Eastern Alaska Range constrained by stacked thermochronology

To address Miocene–present episodic v. persistent exhumation, we utilize a simple graphical procedure that vertically stacks
spatially diverse K-feldspar 40Ar/39Ar multi-domain diffusion (MDD) models from the length of the approximately 100 km-long high-peak region of the Eastern Alaska
Range. We supply additional constraints with 40Ar/39Ar mica dating because the higher closure-temperature-window places limits on the initiation of rapid Eastern Alaska Range
exhumation. We also provide a broad 40Ar/39Ar K-feldspar minimum closure age data set to add more detail on spatial patterns in the regional exhumation history for the
Eastern Alaska Range. We find that rapid and persistent exhumation has occurred in the Eastern Alaska Range since about 24
Ma at a long-term rate of approximately 0.9 km/Ma, but that this rapid exhumation is spatially variable through time. Onset
of rapid Eastern Alaska Range exhumation is coincident with the initiation of rapid exhumation in SW Alaska, the Western Alaska
Range and the Chugach–Saint Elias Range at around 25 Ma, implying a region-wide deformational response to a change in tectonic
forcing. The initiation of highly coupled flat-slab subduction of the Yakutat microplate is probably responsible for this
prolonged period of rapid exhumation in southern Alaska.

为解决中新世至现今的间歇性或持续性抬升问题，本研究采用了一种简明的图形处理方法，将来自东部阿拉斯加山脉约100公里长的高峰区域的空间多样K长石40Ar/39Ar多域扩散（MDD）模型垂直叠加。鉴于较高的封闭温度窗口对东部阿拉斯加山脉快速抬升的起始时间施加了限制，我们引入了40Ar/39Ar云母测年数据作为额外的约束条件。此外，我们还提供了一组广泛的40Ar/39Ar K长石最小封闭年龄数据集，以增加对东部阿拉斯加山脉区域抬升历史中空间模式细节的了解。研究表明，自约24百万年前以来，东部阿拉斯加山脉经历了快速且持续的抬升，其长期抬升速率为约0.9公里/百万年，但这一快速抬升在空间上随时间而变化。东部阿拉斯加山脉快速抬升的起始时间与西南阿拉斯加、西部阿拉斯加山脉和丘加奇-圣伊利亚斯山脉大约在2500万年前的快速抬升同步，这暗示了该区域对构造力变化的广泛变形响应。雅库塔微板块高度耦合的平坦板块俯冲的起始可能是导致阿拉斯加南部长期快速抬升的持续期的原因。