Artículo
New petrographic and geochemical insights on diagenesis and palaeoenvironmental stress in Late Cretaceous inoceramid shells from the James Ross Basin, Antarctica
Fecha de publicación:
12/2006
Editorial:
Cambridge University Press
Revista:
Antarctic Science
ISSN:
0954-1020
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
New petrographic and geochemical insights from inoceramid bivalve shells of lower Campanian (Marambio Group, James Ross Basin, Antarctica) show that they suffered significant palaeoenvironmental stress just before their disappearance in the southern high latitudes. Inoceramid data have mainly been derived from shell fragments of the large form Antarcticeramus rabotensis Crame & Luther, collected at stratigraphical levels marking the early disappearance of inoceramids in the James Ross Basin (10 m.y. before the Cretaceous/Tertiary boundary in Antarctica). Cathodoluminescence studies and minor and trace element intra-shell variations in A. rabotensis shells, along with their whole shell geochemistry (major, minor, and trace elements, including REE), have revealed evidence of only weak diagenesis but significant palaeoenvironmental stress. The most relevant evidence of such adverse palaeoenvironmental conditions in A. rabotensis shells is reflected by marked growth interruptions in the normal shell layering, including the occurrence of a previously undetected inner aragonitic nacreous layer formed of alternating aragonitic and calcitic sublayers. The weak diagenesis produced characteristic geochemical intra-shell variations which have subsequently been detected in the inoceramid shell microstructure, specially in the inner aragonitic nacreous layer.
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Colecciones
Articulos(CADIC)
Articulos de CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Articulos de CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Citación
Álvaro,Jimenez Berrocoso; Olivero, Eduardo Bernardo; Elorza, Javier; New petrographic and geochemical insights on diagenesis and palaeoenvironmental stress in Late Cretaceous inoceramid shells from the James Ross Basin, Antarctica; Cambridge University Press; Antarctic Science; 18; 3; 12-2006; 357-376
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