气候变化领域集成服务门户(CCPortal): Deposition and age of Chicxulub impact spherules on Gorgonilla Island, Colombia

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DOI	10.1130/B35287.1
	Deposition and age of Chicxulub impact spherules on Gorgonilla Island, Colombia
	Mateo P.; Keller G.; Adatte T.; Bitchong A.E.; Spangenberg J.E.; Vennemann T.; Hollis C.J.
发表日期	2020
ISSN	167606
起始页码	215
结束页码	232
卷号	132 期号:2021-01-02
英文摘要	The end-Cretaceous mass extinction (66 Ma) has long been associated with the Chicxulub impact on the Yucatan Peninsula. However, consensus on the age of this impact has remained controversial because of differing interpretations on the stratigraphic position of Chicxulub impact spherules relative to the mass extinction horizon. One side argues that the impact occurred precisely at the Cretaceous-Paleogene boundary, thus coinciding with the mass extinction; the other side argues that the impact predated the Cretaceous-Paleogene boundary, based on the discovery of primary impact spherules deposits in NE Mexico and Texas near the base of planktic foraminiferal zone CF1, dated at 170 k.y. before the Cretaceous-Paleogene boundary. A recent study of the most pristine Chicxulub impact spherules discovered on Gorgonilla Island, Colombia, suggested that they represent a primary impact deposit with an absolute age indistinguishable from the Cretaceous-Paleogene boundary. Here, we report on the Gorgonilla section with the main objective of evaluating the nature of deposition and age of the spherule-rich layer relative to the Cretaceous-Paleogene boundary. The Gorgonilla section consists of light gray-yellow calcareous siliceous mudstones (pelagic deposits) alternating with dark olive-brown litharenites (turbidites). A 3-cmthick dark olive-green spherule-rich layer overlies an erosional surface separating Maastrichtian and Danian sediments. This layer consists of a clast-supported, normally graded litharenite, with abundant Chicxulub impact glass spherules, lithics (mostly volcanic), and Maastrichtian as well as Danian microfossils, which transitions to a calcareous mudstone as particle size decreases. Mineralogical analysis shows that this layer is dominated by phyllosilicates, similar to the litharenites (turbidites) that characterize the section. Based on these results, the spherulerich layer is interpreted as a reworked early Danian deposit associated with turbiditic currents. A major hiatus (>250 k.y.) spanning the Cretaceous-Paleogene boundary and the earliest Danian is recorded at the base of the spherule-rich layer, based on planktic foraminiferal and radiolarian biostratigraphy and carbon stable isotopes. Erosion across the Cretaceous-Paleogene boundary has been recorded worldwide and is generally attributed to rapid climate changes, enhanced bottom-water circulation during global cooling, sea-level fluctuations, and/or intensified tectonic activity. Chicxulub impact spherules are commonly reworked and redeposited into younger sediments overlying a Cretaceous-Paleogene boundary hiatus of variable extent in the Caribbean, Central America, and North Atlantic, while primary deposits are rare and only known from NE Mexico and Texas. Because of their reworked nature, Gorgonilla spherules provide no stratigraphic evidence from which the timing of the impact can be inferred. © 2019 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184879
作者单位	Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Department of Geosciences, Princeton University, PrincetonNJ 08544, United States; Institute of Geology and Paleontology, University of Lausanne, Lausanne, Lausanne, 1015, Switzerland; Department of Earth Sciences, Faculty of Science, University of Yaounde 1, Yaounde, Cameroon; Department of Petroleum and Gas Exploration, Institute of Mines and Petroleum Industries, University of Maroua, Kaele, Cameroon; Institute of Earth Surface Dynamics (IDYST), University of Lausanne, Lausanne, 1015, Switzerland; GNS Science, Lower Hutt5040, New Zealand
推荐引用方式 GB/T 7714	Mateo P.,Keller G.,Adatte T.,et al. Deposition and age of Chicxulub impact spherules on Gorgonilla Island, Colombia[J],2020,132(2021-01-02).
APA	Mateo P..,Keller G..,Adatte T..,Bitchong A.E..,Spangenberg J.E..,...&Hollis C.J..(2020).Deposition and age of Chicxulub impact spherules on Gorgonilla Island, Colombia.Bulletin of the Geological Society of America,132(2021-01-02).
MLA	Mateo P.,et al."Deposition and age of Chicxulub impact spherules on Gorgonilla Island, Colombia".Bulletin of the Geological Society of America 132.2021-01-02(2020).