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Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice

The distribution of life in the continental subsurface is likely controlled by a range of physical and chemical factors. The fundamental requirements are for space to live, carbon for biomass and energy for metabolic activity. These are inter-related, such that adequate permeability is required to m...

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Autores principales: Parnell, John, McMahon, Sean
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society Publishing 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4685966/
https://www.ncbi.nlm.nih.gov/pubmed/26667907
http://dx.doi.org/10.1098/rsta.2014.0293
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author Parnell, John
McMahon, Sean
author_facet Parnell, John
McMahon, Sean
author_sort Parnell, John
collection PubMed
description The distribution of life in the continental subsurface is likely controlled by a range of physical and chemical factors. The fundamental requirements are for space to live, carbon for biomass and energy for metabolic activity. These are inter-related, such that adequate permeability is required to maintain a supply of nutrients, and facies interfaces invite colonization by juxtaposing porous habitats with nutrient-rich mudrocks. Viable communities extend to several kilometres depth, diminishing downwards with decreasing porosity. Carbon is contributed by recycling of organic matter originally fixed by photosynthesis, and chemoautotrophy using crustal carbon dioxide and methane. In the shallow crust, the recycled component predominates, as processed kerogen or hydrocarbons, but abiotic carbon sources may be significant in deeper, metamorphosed crust. Hydrogen to fuel chemosynthesis is available from radiolysis, mechanical deformation and mineral alteration. Activity in the subcontinental deep biosphere can be traced through the geological record back to the Precambrian. Before the colonization of the Earth's surface by land plants, a geologically recent event, subsurface life probably dominated the planet's biomass. In regions of thick ice sheets the base of the ice sheet, where liquid water is stable and a sediment layer is created by glacial erosion, can be regarded as a deep biosphere habitat. This environment may be rich in dissolved organic carbon and nutrients accumulated from dissolving ice, and from weathering of the bedrock and the sediment layer.
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spelling pubmed-46859662016-01-28 Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice Parnell, John McMahon, Sean Philos Trans A Math Phys Eng Sci Articles The distribution of life in the continental subsurface is likely controlled by a range of physical and chemical factors. The fundamental requirements are for space to live, carbon for biomass and energy for metabolic activity. These are inter-related, such that adequate permeability is required to maintain a supply of nutrients, and facies interfaces invite colonization by juxtaposing porous habitats with nutrient-rich mudrocks. Viable communities extend to several kilometres depth, diminishing downwards with decreasing porosity. Carbon is contributed by recycling of organic matter originally fixed by photosynthesis, and chemoautotrophy using crustal carbon dioxide and methane. In the shallow crust, the recycled component predominates, as processed kerogen or hydrocarbons, but abiotic carbon sources may be significant in deeper, metamorphosed crust. Hydrogen to fuel chemosynthesis is available from radiolysis, mechanical deformation and mineral alteration. Activity in the subcontinental deep biosphere can be traced through the geological record back to the Precambrian. Before the colonization of the Earth's surface by land plants, a geologically recent event, subsurface life probably dominated the planet's biomass. In regions of thick ice sheets the base of the ice sheet, where liquid water is stable and a sediment layer is created by glacial erosion, can be regarded as a deep biosphere habitat. This environment may be rich in dissolved organic carbon and nutrients accumulated from dissolving ice, and from weathering of the bedrock and the sediment layer. The Royal Society Publishing 2016-01-28 /pmc/articles/PMC4685966/ /pubmed/26667907 http://dx.doi.org/10.1098/rsta.2014.0293 Text en © 2015 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Articles
Parnell, John
McMahon, Sean
Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice
title Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice
title_full Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice
title_fullStr Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice
title_full_unstemmed Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice
title_short Physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice
title_sort physical and chemical controls on habitats for life in the deep subsurface beneath continents and ice
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4685966/
https://www.ncbi.nlm.nih.gov/pubmed/26667907
http://dx.doi.org/10.1098/rsta.2014.0293
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