کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5781347 1636005 2017 38 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Large-scale mud diapirism as a record of late-stage Laramide tectonism within the Eocene Green River Formation, Wyoming
ترجمه فارسی عنوان
دامپروری دامنه ای بزرگ به عنوان یک رکورد تکتونیسم لارامید در اواخر مرحلۀ در سازند رودخانه سبز ائوسن، وایومینگ
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی
The Gruene and Verde mud diapirs, which range in size from 70 to 95 m in diameter, are exposed within the Wilkins Peak Member of the Eocene Green River Formation near Flaming Gorge Reservoir, southwest Wyoming. These diapirs are sourced from the lower unit of the Wilkins Peak Member (lower, middle, and upper units can be defined based on dominant lithology), and were emplaced into the upper unit of the Wilkins Peak Member, cross-cutting hundreds of meters of strata. The structures contain brecciated dolomicritic and lime mudstones with minor amounts of siliciclastic clays. Pervasive quartz veining is present throughout both diapirs. Though heavily disturbed, original bedding can be seen in both localities, either dipping radially outward towards the margins of the diapir as is dominant at the Gruene diapir or tilted but near horizontal as is the dominant expression at the smaller Verde diapir. The Gruene diapir can be seen in contact with several fluvial sandstone bodies within the upper Wilkins Peak strata in outcrop, and these fluvial sandstones transition from regional, near-horizontal dips to steeply dipping beds and bedsets within 50 m of the diapir. These sands show no signs of brittle deformation, and dip ranges from 20 to 50° radially away from the center of the diapir to the north, west, and east where sands are observed. These are interpreted here to have been deformed pre-lithification, at or near the surface, by the rising mud diapir, offering an important control on the timing of diapirism near the end of the early Eocene. Deformation structures such as clastic dikes, brecciation, and convoluted bedding have been documented by others at or near this stratigraphic interval in Utah, Wyoming, and Colorado, and these smaller structures have been interpreted as seismites. We suggest that these mud diapirs are a larger-scale expression of this same seismic activity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sedimentary Geology - Volume 358, 1 August 2017, Pages 139-147
نویسندگان
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