Chronometry and formation pathways of gypsum using Electron Spin Resonance and Fourier Transform Infrared Spectroscopy

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dc.contributor.authorNagar, Y.C.
dc.contributor.authorSastry, M.D.
dc.contributor.authorBhushan, B
dc.contributor.authorKumar, A.
dc.contributor.authorMishra, K.P.
dc.contributor.authorShastri, A
dc.contributor.authorDeo, M.N.
dc.contributor.authorKocurek, G.
dc.contributor.authorMagee, John
dc.contributor.authorWadhawan, S.K.
dc.contributor.authorJuyal, N.
dc.contributor.authorPandian, M.S.
dc.contributor.authorShukla, A.D.
dc.contributor.authorSinghvi, A.K.
dc.date.accessioned2015-12-10T23:07:41Z
dc.date.issued2010
dc.date.updated2016-02-24T08:32:26Z
dc.description.abstractGypsum is an authigenic precipitate that forms under periods of accentuated aridity and occurs widely in arid zones. However its use in quantitative paleoclimatology has been limited due to the absence of a method to determine the timing of its formation. We present here the results of a feasibility study that demonstrates that the timing of the formation event of gypsum can be estimated using Electron Spin Resonance (ESR) analysis. We used well documented samples from White Sands in New Mexico, USA, the Thar Desert, India and lakes in the Simpson Desert and Mallee Region, Australia and found that ESR ages could be obtained using radiation sensitive SO4-, SO3- radicals and a photobleachable signal O3-. ESR signals were consistent with control ages based on contextual information. These suggest that the dating signals (SO4-, SO3-) are stable over time scales >100 ka. We propose that this stability of the SO4- signals over geological time scales arises due to hydrogen bonding between the water proton and the SO4- radical and that the suitability of these radiation-induced radicals comes from their being a part of the host matrix. Further, ESR along with Fourier Transform Infrared (FT-IR) Spectroscopy methods additionally inform on the geochemical pathways for gypsum formation and help elucidate complex formation processes even in samples that appeared unambiguous gypsum precipitates. Thus, the presence of Hannebachite (CaSO3.1/2H2O) and Mn2+ in Thar and Australian samples suggested a reducing environment such that low valence sulfur reacted with CaCO3 to form hannebachite and eventually gypsum. The presence of sulfur, partially as sulfite in Thar gypsum samples suggested that redox cycles were mediated by microbial activity. Absence of these features in White Sands samples suggested oxic conditions during gypsum precipitation.
dc.identifier.issn1871-1014
dc.identifier.urihttp://hdl.handle.net/1885/62981
dc.publisherElsevier
dc.sourceQuaternary Geochronology
dc.subjectKeywords: aridity; calcium carbonate; electron spin resonance dating; FTIR spectroscopy; gypsum; microbial activity; paleoclimate; Australia; New Mexico; Simpson Desert; Thar Desert; United States; White Sands
dc.titleChronometry and formation pathways of gypsum using Electron Spin Resonance and Fourier Transform Infrared Spectroscopy
dc.typeJournal article
local.bibliographicCitation.issue6
local.bibliographicCitation.lastpage704
local.bibliographicCitation.startpage691
local.contributor.affiliationNagar, Y.C., Physical Research Laboratory
local.contributor.affiliationSastry, M.D., Physical Research Laboratory
local.contributor.affiliationBhushan, B, Bhabha Atomic Research Centre
local.contributor.affiliationKumar, A., Radiation Biology & Health Sciences Division, Bhabha Atomic Research Center
local.contributor.affiliationMishra, K.P., Radiation Biology & Health Sciences Division, Bhabha Atomic Research Center
local.contributor.affiliationShastri, A, Bhabha Atomic Research Centre
local.contributor.affiliationDeo, M.N., Bhabha Atomic Research Centre
local.contributor.affiliationKocurek, G., Texas University
local.contributor.affiliationMagee, John, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationWadhawan, S.K., Geological Survey of India
local.contributor.affiliationJuyal, N., Physical Research Laboratory
local.contributor.affiliationPandian, M.S., Pondicherry University
local.contributor.affiliationShukla, A.D., Physical Research Laboratory
local.contributor.affiliationSinghvi, A.K., Physical Research Laboratory
local.contributor.authoremailu7700267@anu.edu.au
local.contributor.authoruidMagee, John, u7700267
local.description.embargo2037-12-31
local.description.notesImported from ARIES
local.identifier.absfor040605 - Palaeoclimatology
local.identifier.absseo970105 - Expanding Knowledge in the Environmental Sciences
local.identifier.ariespublicationf2965xPUB757
local.identifier.citationvolume5
local.identifier.doi10.1016/j.quageo.2010.05.001
local.identifier.scopusID2-s2.0-78149498026
local.identifier.uidSubmittedByf2965
local.type.statusPublished Version

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