Evolution patterns of glaucony maturity: A mineralogical and geochemical approach. (Articolo in rivista)

Type
Label
  • Evolution patterns of glaucony maturity: A mineralogical and geochemical approach. (Articolo in rivista) (literal)
Anno
  • 2007-01-01T00:00:00+01:00 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi
  • 10.1016/j.dsr2.2007.04.006 (literal)
Alternative label
  • Amorosi A.; Sammartino I.; Tateo F. (2007)
    Evolution patterns of glaucony maturity: A mineralogical and geochemical approach.
    in Deep-sea research. Part 2. Topical studies in oceanography
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Amorosi A.; Sammartino I.; Tateo F. (literal)
Pagina inizio
  • 1364 (literal)
Pagina fine
  • 1374 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 54 (literal)
Rivista
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • Dipartimento di Scienze della Terra e Geologico-Ambientali, University of Bologna, 40127 Bologna, Italy Dipartimento di Scienze della Terra e Geologico-Ambientali, University of Bologna, 40127 Bologna, Italy C.N.R. sezione di Padova, Istituto di Geoscienze e Georisorse, Via Giotto 1, Padova, Italy (literal)
Titolo
  • Evolution patterns of glaucony maturity: A mineralogical and geochemical approach. (literal)
Abstract
  • Integrated mineralogical and geochemical analyses were carried out on a wide variety of glauconitic grains from 25 western European localities, covering the whole range of glaucony maturity and ranging in age between the Cretaceous and the Piliocene. A comprehensive data set documents the major evolution patterns of glaucony and the relationships between glauconitic minerals and their substrate components. Increasing glaucony maturity involves potassium and rubidium enrichment. The progressive evolution from a K-poor glauconitic smectite to a K-rich glauconitic mica is accompanied by the overall decrease of distance between peaks (001) and (020). The width of basal reflection (001), however, is proposed here as a more powerful tool for the discrimination of glauconitic minerals at different stages of maturity. This parameter is especially efficient for the differentiation of evolved and highly-evolved glaucony. The range of initial substrate composition appears to control significantly major and trace element variations during glaucony maturation. Contrasting patterns are observed in glauconitic grains, as a function of the proportion of carbonate versus siliciclastic substrate components. Particularly, the distribution patterns of MgO and SiO2 in glaucony associated with carbonate host rocks suggest progressive uptake of these elements in the structure of glauconitic minerals, with increasing degree of maturation. By contrast, a decrease in SiO2 and AI(2)O(3) with increasing maturity may be observed when the substrate for glauconitization is represented by siliciclastic material. Fe shows a positive correlation with K2O in glaucony with low maturity, but an opposite trend in evolved glaucony. Therefore, Fe cannot be regarded as a reliable indicator of glaucony maturity. Maturation of glauconitic minerals results invariably in Ca- (and Sr-) depletion, irrespective of the original composition of the precursor material. As a consequence, the proportion of Ca and Sr may be considered as an inverse, relative criterion of glauconitic mineral evolution for a given source area. (literal)
Prodotto di
Autore CNR
Insieme di parole chiave

Incoming links:


Autore CNR di
Prodotto
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi
Insieme di parole chiave di
data.CNR.it