Glauconites from the Late Palaeocene — Early Eocene Naredi Formation, western Kutch and their genetic implications

Abstract

Glauconitic minerals are considered as one of the valuable input parameters in sequence stratigraphic analysis of a basin. In the present study glauconitic minerals are reported from subtidal green shale facies in the lower part of the Late Paleocene-Early Eocene Naredi Formation of western Kutch. On the basis of the foraminiferal assemblage the glauconite bearing beds are interpreted to have formed in a mid shelf depositional settings of an unstable marine conditions. XRD studies confirm the glauconite mineralogy of the green pellets and provide an estimation of glauconite maturity. Textural attributes of the glauconites confirm their derivation by different degrees of alteration of precursor feldspar grains. Because of the authigenic origin and autochthonous nature, these glauconites hold promise for understanding sequence stratigraphy of the Palaeogene succession of the western Kutch.

Substrate control on formation and maturation of glauconites in the Middle Eocene Harudi Formation, western Kutch, India

“…The underlying Naredi Formation is overall shallowing and is topped by a lateritized palaeosol with abundant rootlets (Fig. 3A) (Biswas, 1992;Chattoraj et al, 2009).…”

“…Glauconite pellets are known to occur in marine sedimentary rocks ranging in age from Palaeoproterozoic to recent (Odin and Matter, 1981;Dasgupta et al, 1990;Amorosi, 1994;Chafetz and Reid, 2000;Lee et al, 2002;El Albani et al, 2005;Meunier and El Albani, 2007 and references therein; Amorosi et al, 2007;Bandopadhyay, 2007;Banerjee et al, 2008;Chattoraj et al, 2009). Glauconite is generally considered as common authigenic product of marine environment and is indicative of low sedimentation rate (Amorosi, 1995(Amorosi, , 1997Ghibaudo et al, 1996;Kitamura, 1998;Amorosi and Centineo, 2000;Harris and Whiting, 2000;Giresse and Wiewióra, 2001;Hesselbo and Huggett, 2001;Banerjee et al, 2008;Chattoraj et al, 2009).…”

“…Glauconite is generally considered as common authigenic product of marine environment and is indicative of low sedimentation rate (Amorosi, 1995(Amorosi, , 1997Ghibaudo et al, 1996;Kitamura, 1998;Amorosi and Centineo, 2000;Harris and Whiting, 2000;Giresse and Wiewióra, 2001;Hesselbo and Huggett, 2001;Banerjee et al, 2008;Chattoraj et al, 2009). Most of these studies highlight sedimentation rate as the most crucial factor involved in formation and maturation of glauconite.…”

“…Recently Chattoraj et al (2009) reported glauconite pellets in the green shale facies of Early Eocene Naredi Formation and discussed their stratigraphic implications. The present paper describes glauconite from the Middle Eocene Harudi Formation with reference to its facies-specific and stratigraphic interval-specific occurrence, and documents their petrographic characteristics, modes of occurrence, mineralogy and geochemistry.…”

The origin and maturation of lagoonal glauconites: a case study from the Oligocene Maniyara Fort Formation, western Kutch, India

“…With this goal in mind, this paper attempts to understand the origin, maturation and evolution of the glauconite formed within foraminiferal tests and faecal pellets of the Oligocene Maniyara Fort Formation in western Kutch, India in a holistic perspective. Though the biostratigraphy of the Palaeogene succession in Kutch is well documented, sedimentological studies are rare (Singh, ; Saraswati and Banerji, ; Chattoraj et al ., ). The depositional environment of the Maniyara Fort Formation is interpreted here using combined sedimentological and micropalaeontological data, and the mineralogical and chemical characteristics of the glauconites present in the Formation are interpreted in the backdrop of the depositional setting of the Maniyara Fort Formation.…”