Impact and habitability scenarios for early Mars revisited based on a 4.45-Ga shocked zircon in regolith breccia

被引：9

作者：

Cox, Morgan A. ^{[1
]}

Cavosie, Aaron J. ^{[1
]}

Orr, Kenneth J. ^{[1
]}

Daly, Luke ^{[2
]}

Martin, Laure ^{[3
]}

Lagain, Anthony ^{[1
]}

Benedix, Gretchen K. ^{[1
,4
]}

Bland, Phil A. ^{[1
]}

机构：

[1] Curtin Univ, Space Sci & Technol Ctr SSTC, Sch Earth & Planetary Sci, Perth, WA 6102, Australia

[2] Univ Glasgow, Sch Geog & Earth Sci, Glasgow G12 8QQ, Lanark, Scotland

[3] Univ Western Australia, Ctr Microscopy Characterisat & Anal CMCA, 6 Verdun St, Perth, WA 6009, Australia

[4] Western Australian Museum, Dept Earth & Planetary Sci, Perth, WA, Australia

来源：

SCIENCE ADVANCES | 2022年 / 8卷 / 05期

关键词：

DETRITAL ZIRCONS; EVOLUTION; CRUST; METEORITE; PB; MICROSTRUCTURES; CHRONOLOGY; COMPONENTS; PRESSURE; HISTORY;

D O I：

10.1126/sciadv.abl7497

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

After formation of a primordial crust, early impacts influenced when habitable conditions may have occurred on Mars. Martian meteorite Northwest Africa (NWA) 7034 is a regolith breccia that contains remnants of the earliest Martian crust. The paucity of shock deformation in NWA 7034 was previously cited as recording a decline in giant impacts by 4.48 billion years and evidence for habitable Mars by 4.2 billion years ago. We present new evidence of high-pressure shock effects in a 4.45-billion year-old zircon from the matrix of NWA 7034. The zircon contains {112} shock twins formed in the central uplift of a complex impact structure after 4.45 billion years and records impact pressures of 20 to 30 gigapascals. The zircon represents the highest shock level reported in NWA 7034 and paired rocks and provides direct physical evidence of large impacts, some potentially life-affecting, that persisted on Mars after 4.48 billion years.

引用

页数：6