Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1130/B35043.1 |
Detrital zircon double-dating of forearc basin strata reveals magmatic, exhumational, and thermal history of sediment source areas | |
Enkelmann, Eva1; Lohff, Sonia K. Sanchez2; Finzel, Emily S.3 | |
2019-07-01 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN
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ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2019 |
卷号 | 131页码:1364-1384 |
文章类型 | Article |
语种 | 英语 |
国家 | Canada; USA |
英文摘要 | Subduction along the southern margin of Alaska, USA, has been ongoing since at least the Jurassic. However, the character of the subducting slab has changed through time and has included subduction of normal oceanic crust, a spreading ridge, and an oceanic plateau. The latter two resulted in a change of subduction mode by inducing a shallow subduction angle. Geologic processes and landscape evolution of the overriding plate were affected by these variations in subduction mode and are recorded in the forearc basin strata. We investigate the Cenozoic to modern sediment of the forearc Cook Inlet basin in south-central Alaska. Here we use a double-dating approach that combines fission track dating and U-Pb dating on individual detrital zircon grains. In total we analyzed more than 1700 zircons from Eocene to Pliocene strata and modern river sand that has eroded from the surrounding regions of the Cook Inlet basin. The double-dating approach combined with the existing knowledge of the regional geology allows us to discriminate between magmatic cooled grains of extrusive and shallow intrusive rocks, exhumational cooled grains, and thermal reset grains. We find that the erosion of both shallow and deep intrusive arc rocks dominate the detrital age signal, while syn-depositional extrusive grains are lacking. The erosion of rocks that have been thermally altered during the subduction of a spreading ridge dominates the fission track (FT) age signal. This pattern is particularly prominent in the accretionary prism where ages in the most inboard (older) portion have not been thermally reset, but thermal resetting is prevalent in the outboard (younger) portion located proximal to the Paleocene-Eocene near-trench intrusions. Thermal alteration is also evident in the region of the arc that was affected by the passage of the asthenospheric slab window. The erosional signal of the more inboard arc and backarc region (Alaska Range) is characterized by exhumational FT ages of deep-seated rocks, which currently provide material into the forearc basin. This age signal results from flat-slab subduction of the Yakutat microplate, which transfers stress far inboard and produces significant mountain building and deformation. This exhumational age signal, however, is not recorded in the late Cenozoic strata, suggesting that the modern landscape developed since <3 Ma. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000471802800016 |
WOS关键词 | CHUGACH METAMORPHIC COMPLEX ; PRINCE-WILLIAM-SOUND ; EASTERN ALASKA RANGE ; STRIKE-SLIP ; FOCUSED EXHUMATION ; TECTONIC EVOLUTION ; ALEXANDER TERRANE ; CONVERGENT MARGIN ; RIDGE SUBDUCTION ; SOUTHEAST ALASKA |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/184606 |
专题 | 地球科学 |
作者单位 | 1.Univ Calgary, Dept Geosci, 2500 Univ Dr NW, Calgary, AB T2N 1N4, Canada; 2.Univ Cincinnati, Dept Geol, 500 Geol Phys Bldg, Cincinnati, OH 45221 USA; 3.Univ Iowa, Dept Earth & Environm Sci, 115 Trowbridge Hall, Iowa City, IA 52242 USA |
推荐引用方式 GB/T 7714 | Enkelmann, Eva,Lohff, Sonia K. Sanchez,Finzel, Emily S.. Detrital zircon double-dating of forearc basin strata reveals magmatic, exhumational, and thermal history of sediment source areas[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2019,131:1364-1384. |
APA | Enkelmann, Eva,Lohff, Sonia K. Sanchez,&Finzel, Emily S..(2019).Detrital zircon double-dating of forearc basin strata reveals magmatic, exhumational, and thermal history of sediment source areas.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,131,1364-1384. |
MLA | Enkelmann, Eva,et al."Detrital zircon double-dating of forearc basin strata reveals magmatic, exhumational, and thermal history of sediment source areas".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 131(2019):1364-1384. |
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