Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1130/B31925.1 |
The Decorah structure, northeastern Iowa: Geology and evidence for formation by meteorite impact | |
French, Bevan M.1; McKay, Robert M.2; Liu, Huaibao P.2; Briggs, Derek E. G.3,4; Witzke, Brian J.5 | |
2018-11-01 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN
![]() |
ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2018 |
卷号 | 130页码:2062-2086 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | The Decorah structure, recently discovered in northeastern Iowa, now appears as an almost entirely subsurface, deeply eroded circular basin 5.6 km in diameter and similar to 200 m deep, that truncates a near-horizontal series of Upper Cambrian to Lower Ordovician platform sediments. Initial analysis of geological and well-drilling data indicated characteristics suggestive of meteorite impact: a circular outline, a shallow basin shape, discordance with the surrounding geology, and a filling of anomalous sediments: (1) the organic-rich Winneshiek Shale, which hosts a distinctive fossil Lagerstatte, (2) an underlying breccia composed of fragments from the surrounding lithologies, and (3) a poorly known series of sediments that includes shale and possible breccia. Quartz grains in drill samples of the breccia unit contain abundant distinctive shock-deformation features in similar to 1% of the individual quartz grains, chiefly planar fractures (cleavage) and planar deformation features (PDFs). These features provide convincing evidence that the Decorah structure originated by meteorite impact, and current models of meteorite crater formation indicate that it formed as a complex impact crater originally similar to 6 km in diameter. The subsurface characteristics of the lower portion of the structure are not well known; in particular, there is no evidence for the existence of a central uplift, a feature generally observed in impact structures of comparable size. The current estimated age of the Decorah structure (460-483 Ma) suggests that it may be associated with a group of Middle Ordovician impact craters (a terrestrial "impact spike") triggered by collisions in the asteroid belt at ca. 470 Ma. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000449028300019 |
WOS关键词 | ORDOVICIAN WINNESHIEK LAGERSTATTE ; PLANAR DEFORMATION FEATURES ; TERRESTRIAL IMPACT ; SHOCK METAMORPHISM ; LOCKNE CRATER ; EXTRATERRESTRIAL CHROMITE ; KONSERVAT-LAGERSTATTE ; QUARTZ ; BREAKUP ; ORIGIN |
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/24846 |
专题 | 地球科学 |
作者单位 | 1.Smithsonian Inst, Dept Paleobiol, Washington, DC 20013 USA; 2.Univ Iowa, Iowa Geol Survey, IIHR Hydrosci & Engn, 340 Trowbridge Hall, Iowa City, IA 52242 USA; 3.Yale Univ, Dept Geol & Geophys, New Haven, CT 06520 USA; 4.Yale Univ, Yale Peabody Museum Nat Hist, New Haven, CT 06520 USA; 5.Univ Iowa, Dept Earth & Environm Sci, 121 Trowbridge Hall, Iowa City, IA 52242 USA |
推荐引用方式 GB/T 7714 | French, Bevan M.,McKay, Robert M.,Liu, Huaibao P.,et al. The Decorah structure, northeastern Iowa: Geology and evidence for formation by meteorite impact[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2018,130:2062-2086. |
APA | French, Bevan M.,McKay, Robert M.,Liu, Huaibao P.,Briggs, Derek E. G.,&Witzke, Brian J..(2018).The Decorah structure, northeastern Iowa: Geology and evidence for formation by meteorite impact.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,130,2062-2086. |
MLA | French, Bevan M.,et al."The Decorah structure, northeastern Iowa: Geology and evidence for formation by meteorite impact".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 130(2018):2062-2086. |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论