Conditions of subaerial weathering of basalts in the Neoarchean and Paleoproterozoic

dc.creatorAlfimova, NA
dc.creatorNovoselov, AA
dc.creatorMatrenichev, V
dc.creatorFilho, CRDS
dc.date2014
dc.dateFEB
dc.date2014-07-30T14:00:35Z
dc.date2015-11-26T16:33:31Z
dc.date2014-07-30T14:00:35Z
dc.date2015-11-26T16:33:31Z
dc.date.accessioned2018-03-28T23:15:25Z
dc.date.available2018-03-28T23:15:25Z
dc.identifierPrecambrian Research. Elsevier Science Bv, v. 241, n. 1, n. 16, 2014.
dc.identifier0301-9268
dc.identifier1872-7433
dc.identifierWOS:000331427500001
dc.identifier10.1016/j.precamres.2013.09.013
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/56469
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/56469
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1270883
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionPrecambrian weathering profiles (or regoliths) were formed on the Earth's surface in contact with meteoritic water. This signifies that their mineral and bulk composition should reflect the environmental conditions at the time of weathering. The aim of this study is to reconstruct the main mineralogical and chemical trends involved in the formation of Precambrian weathering regoliths by means of geochemical modeling verified through laboratory experimentation. We have demonstrated that, in a wide range of modeling conditions, weathering profiles of basalts consist mostly of clay minerals (smectites and illite). Carbonate minerals may also be deposited within the profile at the initial stage of weathering, which are later dissolved during a further process. The time, necessary for complete dissolution of primary minerals and crystallization of authigenic minerals is between 100 and 140 Kyr. Modeling results indicate that Neoarchean and Paleoproterozoic (2.8-2.0 Ga) weathering profiles were formed under an atmosphere with pCO(2) not much higher than 25 PAL and climatic conditions close to those found in modern times. Weathering under CO2-rich (pCO(2) = 1 and 10 bar) and CH4-rich atmospheres as well as high temperature (50 degrees C and 75 degrees C) conditions do not produce compounds corresponding to the analyzed samples. (C) 2013 Elsevier B.V. All rights reserved.
dc.description241
dc.description1
dc.description16
dc.descriptionRFFI (Russian Foundation for Fundamental Investigations) [12-04-00102]
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionIGCP-SIDA project [599]
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionRFFI (Russian Foundation for Fundamental Investigations) [12-04-00102]
dc.descriptionFAPESP [2011/12682-3]
dc.descriptionIGCP-SIDA project [599]
dc.languageen
dc.publisherElsevier Science Bv
dc.publisherAmsterdam
dc.publisherHolanda
dc.relationPrecambrian Research
dc.relationPrecambrian Res.
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectChemical weathering
dc.subjectPrecambrian
dc.subjectAtmosphere
dc.subjectClimate
dc.subjectGeochemical modeling
dc.subjectSturgeon Falls Paleosol
dc.subjectAtmospheric Co2 Levels
dc.subjectSouth-africa
dc.subjectPrecambrian Paleosols
dc.subjectOxidation-kinetics
dc.subjectBillion Years
dc.subjectOxygen
dc.subjectDissolution
dc.subjectEvolution
dc.subjectClimate
dc.titleConditions of subaerial weathering of basalts in the Neoarchean and Paleoproterozoic
dc.typeArtículos de revistas


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