High-resolution temporal and stratigraphic record of Siletzia’s accretion and triple junction migration from nonmarine sedimentary basins in central and western Washington
High-resolution temporal and stratigraphic record of Siletzia’s accretion and triple junction migration from nonmarine sedimentary basins in central and western Washington
复制标题
华盛顿州中部和西部非海相沉积盆地的 Siletzia 增生和三交点迁移的高分辨率时间和地层记录
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
E. Donaghy
中科院分区：
文献类型：
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作者：
M. Eddy;S. Bowring;P. Umhoefer;R. Miller;N. McLean;E. Donaghy
早始新世在西部华盛顿和南部不列颠哥伦比亚省的近海沟岩浆活动的存在，导致了推测，这一地区经历了脊沟互动在这段时间。然而，这一过程的影响，因为他们被保存在地质记录的其他部分知之甚少。本文介绍了华盛顿中部和西部古近纪非海相沉积和火山岩序列中高精度的锆石U-Pb年代学，这些序列保存了约100年至200年的构造事件记录。60和45 Ma。资料显示，在≤59.9 ~ 51.3 Ma之间，Swauk组、Chuckanut组和Manastash组形成了沿着北美边缘的一个非海相沉积盆地。该盆地经历了重大的破坏，最终在盆地变形，隆起，并在51.3和49.9马之间的Siletzia的加积部分侵蚀。紧接着加积，右旋走滑断层开始，或加速，在达林顿魔鬼山，Dallat，Leavenworth，鹰溪，和直溪弗雷泽断层带之间的50和46马。在此期间，Chumstick组沉积在一个走滑盆地，与近海沟岩浆作用同时代。断层继续在Dallat，Eagle Creek和Leavenworth断层上，直到区域沉积盆地重新建立≤45.9 Ma，并可能在Straight Creek-Fraser断层上持续到35-30 Ma。这种盆地破裂、火山活动和走滑断层作用的记录与海脊-海沟相互作用相一致，并支持始新世早期沿沿着北美边缘在该纬度存在大洋扩张脊。
The presence of early Eocene near-trench magmatism in western Washington and southern British Columbia has led to speculation that this area experienced ridge-trench interaction during that time. However, the effects of this process as they are preserved in other parts of the geologic record are poorly known. We present high-precision U-Pb zircon geochronology from Paleogene nonmarine sedimentary and volcanic sequences in central and western Washington that preserve a record of tectonic events between ca. 60 and 45 Ma. The data reveal that the Swauk, Chuckanut, and Manastash Formations formed a nonmarine sedimentary basin along the North American margin between ≤59.9 and 51.3 Ma. This basin experienced significant disruption that culminated in basinwide deformation, uplift, and partial erosion during accretion of the Siletzia terrane between 51.3 and 49.9 Ma. Immediately following accretion, dextral strike-slip faulting began, or accelerated, on the Darrington–Devil’s Mountain, Entiat, Leavenworth, Eagle Creek, and Straight Creek–Fraser fault zones between 50 and 46 Ma. During this time, the Chumstick Formation was deposited in a strike-slip basin coeval with near-trench magmatism. Faulting continued on the Entiat, Eagle Creek, and Leavenworth faults until a regional sedimentary basin was reestablished ≤45.9 Ma, and may have continued on the Straight Creek–Fraser fault until 35–30 Ma. This record of basin disruption, volcanism, and strike-slip faulting is consistent with ridge-trench interaction and supports the presence of an oceanic spreading ridge at this latitude along the North American margin during the early Eocene.
影响因子：
5
作者：
Condon, D. J.;Schoene, B.;Parrish, R. R.
通讯作者：
Parrish, R. R.