气候变化领域集成服务门户(CCPortal): Hydrothermal alteration associated with the Chicxulub impact crater upper peak-ring breccias

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DOI	10.1016/j.epsl.2020.116425
	Hydrothermal alteration associated with the Chicxulub impact crater upper peak-ring breccias
	Simpson S.L.; Osinski G.R.; Longstaffe F.J.; Schmieder M.; Kring D.A.
发表日期	2020
ISSN	0012821X
卷号	547
英文摘要	The 66 Ma, ∼180 km Chicxulub impact structure in the northern Yucatán peninsula and southern Gulf of Mexico is the best-preserved large impact crater on Earth with a well-developed peak ring. The most recent drilling campaign took place offshore during the joint International Ocean Discovery Program – International Continental Scientific Drilling Program (IODP–ICDP) Expedition 364 at site M0077A (21.45°N, 89.95°W) and recovered ∼830 m of continuous core. Initial examination revealed that the peak-ring comprises four main lithological units (from the base upwards): crystalline basement granitoid rocks (Unit 4); a thin layer of impact melt rocks (Units 3A and B); melt-bearing breccias (Units 2A–C); and post-impact sedimentary rocks (Unit 1). Preliminary analysis of the drill core indicated that hydrothermal alteration has affected all lithologies and is especially pervasive in the melt-bearing breccias of Unit 2 (721.6 to 617.33 meters below sea floor, mbsf). Here we present the first detailed investigation of hydrothermal alteration within the melt-bearing breccias. Alteration phases are predominantly Fe-Mg clay minerals, zeolites, alkali feldspars, calcite and minor sulfides, sulfates, opal and Fe-Ti oxides. Alteration is especially intense proximal to lithologic contacts, particularly at the base of subunit 2B where there is an abrupt increase in host rock porosity ∼30 m above the impact melt rocks. The pervasiveness of clay minerals and zeolites is attributed to the high amounts of devitrified silicate glass throughout Unit 2. The phases preserved here are consistent with the findings of previous hydrothermal studies in other areas of the Chicxulub structure, and suggest an evolving water-rock system that was alkaline-saline, comparable to seawater-volcanic glass alteration. © 2020 Elsevier B.V.
关键词	astrobiology Chicxulub impact impact cratering impact generated hydrothermal systems
英文关键词	Binary alloys; Calcite; Clay minerals; Core drilling; Feldspar; Glass; Infill drilling; Iron alloys; Iron oxides; Lithology; Magnesium alloys; Offshore oil well production; Saline water; Sedimentary rocks; Silicates; Structural geology; Sulfur compounds; Titanium alloys; Titanium oxides; Zeolites; Alkali feldspar; Alteration phasis; Chicxulub impact; Continental scientific drillings; Crystalline basement; Granitoid rocks; Hydrothermal alterations; Preliminary analysis; Clay alteration; breccia; crater; granitoid; hydrothermal alteration; lithology; volcanic glass; water-rock interaction; zeolite; Bay of Campeche; Chicxulub Crater; Mexico [North America]; Yucatan
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202890
作者单位	Department of Earth Sciences, Institute for Earth and Space Exploration, The University of Western OntarioON N6A 3K7, Canada; Lunar and Planetary Institute, Universities Space Research Association, Houston, TX 77058, United States
推荐引用方式 GB/T 7714	Simpson S.L.,Osinski G.R.,Longstaffe F.J.,et al. Hydrothermal alteration associated with the Chicxulub impact crater upper peak-ring breccias[J],2020,547.
APA	Simpson S.L.,Osinski G.R.,Longstaffe F.J.,Schmieder M.,&Kring D.A..(2020).Hydrothermal alteration associated with the Chicxulub impact crater upper peak-ring breccias.Earth and Planetary Science Letters,547.
MLA	Simpson S.L.,et al."Hydrothermal alteration associated with the Chicxulub impact crater upper peak-ring breccias".Earth and Planetary Science Letters 547(2020).