Impact craters as biospheric microenvironments, Lawn Hill Structure, northern AustraliaReportar como inadecuado




Impact craters as biospheric microenvironments, Lawn Hill Structure, northern Australia - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Reference: John Lindsay and Martin Brasier, (2006). Impact craters as biospheric microenvironments, Lawn Hill Structure, northern Australia. Astrobiology, 6 (2), 348-363.Citable link to this page:

 

Impact craters as biospheric microenvironments, Lawn Hill Structure, northern Australia

Abstract: Impact craters on Mars act as traps for eolian sediment and in the past may have provided suitable microenvironments that could have supported and preserved a stressed biosphere. If this is so, terrestrial impact structures such as the 18-km-diameter Lawn Hill Structure, in northern Australia, may prove useful as martian analogs. We sampled outcrop and drill core from the carbonate fill of the Lawn Hill Structure and recorded its gamma-log signature. Facies data along with whole rock geochemistry and stable isotope signatures show that the crater fill is an outlier of the Georgina Basin and was formed by impact at, or shortly before, approximately 509-506 million years ago. Subsequently, it was rapidly engulfed by the Middle Cambrian marine transgression, which filled it with shallow marine carbonates and evaporites. The crater formed a protected but restricted microenvironment in which sediments four times the thickness of the nearby basinal succession accumulated. Similar strutures, common on the martian surface, may well have acted as biospheric refuges as the planet's water resources declined. Low-pH aqueous environments on Earth similar to those on Mars, while extreme, support diverse ecologies. The architecture of the eolian crater fill would have been defined by long-term ground water cycles resulting from intermittent precipitation in an extremely arid climate. Nutrient recycling, critical to a closed lacustrine sub-ice biosphere, could be provided by eolian transport onto the frozen water surface.

Publication status:PublishedPeer Review status:Peer reviewedVersion:Publisher's versionNotes:This is a copy of an article was published in Astrobiology © 2006 Mary Ann Liebert, Inc.; Astrobiology is available online at: http://www.liebertonline.com.

Bibliographic Details

Publisher: Mary Ann Liebert, Inc.

Publisher Website: http://www.liebertonline.com/

Host: Astrobiologysee more from them

Publication Website: http://www.liebertpub.com/products/product.aspx?pid=99

Issue Date: 2006-May

Copyright Date: 2006

pages:348-363Identifiers

Doi: https://doi.org/10.1089/ast.2006.6.348

Issn: 1531-1074

Eissn: 1557-8070

Urn: uuid:c9796531-6943-4302-9733-8e8616adf78a Item Description

Type: Article: post-print;

Language: en

Version: Publisher's versionKeywords: Martian analog impact craters Cambrian Lawn Hill Structure northern AustraliaSubjects: Earth sciences Tiny URL: ora:5497

Relationships





Autor: John Lindsay - institutionLunar and Planetary Institute, Houston, Texas - - - Martin Brasier - institutionUniversity of Oxford fa

Fuente: https://ora.ox.ac.uk/objects/uuid:c9796531-6943-4302-9733-8e8616adf78a



DESCARGAR PDF




Documentos relacionados