Mineralogical, geochemical and isotopic characteristics of Quaternary calcretes in the Adana region, southern Turkey: Implications on their origin

A microscopic approach to the pedogenic formation of palygorskite associated with Quaternary calcretes of the Adana area, southern Turkey

“…Palygorskite frequently occurs within calcrete nodules, tubes, and fracture-infills and adjacent host-rock mudstone in the calcrete profile/section. The abundance of β-fabric (biogenic) constituents in the calcrete hardpan (Kaplan et al, 2013) such as rhizoliths, calcite needles, and calcified filaments suggests that palygorskite development likely took place within a biogenically active zone of a soil profile. In addition, the presence of circumgranular and desiccation cracks, alveolar textures, vadose pisolites, and vadose silts in the hardpan suggests the formation of palygorskite in the vadose environment (Hassouba and Shaw, 1980;Eren et al, 2004Eren et al, , 2008Kaplan et al, 2013).…”

“…In addition, the presence of circumgranular and desiccation cracks, alveolar textures, vadose pisolites, and vadose silts in the hardpan suggests the formation of palygorskite in the vadose environment (Hassouba and Shaw, 1980;Eren et al, 2004Eren et al, , 2008Kaplan et al, 2013). The vadose environment is also supported by the presence of the clay coatings as determined by Kapur et al (1987) and Kaplan et al (2013) present within the calcrete nodules and tubes, and the development of palygorskite as sheetlike fibre bundles (Figure 7b) and fibre bridges as meniscus cement between the calcite crystals (Figures 7d, 7e, and 8d). The pedogenic origin of palygorskite is inferred from Strong et al, 1992;Jimenez de Cisneros et al, 1993;Alonso-Zarza and Arenas, 2004;Eren et al, 2004Eren et al, , 2008Shaaban, 2004;Gong et al, 2005;Kaplan et al, 2013), whereas the δ 13 C values reflect a high input of soil-derived CO 2 and are also consistent with a pedogenic origin for the calcrete and associated palygorskite (Cerling, 1984(Cerling, , 1992Boutton, 1991;Wright and Tucker, 1991;Alonso-Zarza, 1999;Eren et al, 2004Eren et al, , 2008Bajnoczi et al, 2006;Kaplan et al, 2013).…”

“…Its occurrence is also reported from calcretes as a minor component (Wright and Tucker, 1991;Verrecchia and Le Coustumer, 1996;Eren et al, 2008;Kaplan et al, 2013). Palygorskite studies are frequent in the literature (e.g., Singer and Norrish, 1974;Elprince et al, 1979;Verrecchia and Le Coustumer, 1996;Krekeler et al, 2005;Kadir and Eren, 2008;Garcia-Romero and Suárez, 2010;Galán and Pozo, 2011;Yalçın and Bozkaya, 2011;Yeniyol, 2012), and some stress the widespread pedogenic occurrence of palygorskite in contemporary arid and semiarid climatic zones of the globe (e.g., Singer and Norrish, 1974;Elprince et al, 1979;Hassouba and Shaw, 1980;Botha and Hughes, 1992;Hillier and Pharande, 2008).…”

“…Nonetheless, despite the limited area covered, i.e. confined to the boundaries of Turkey, the studies conducted by Yılmaz (1999), Kapur et al (1987Kapur et al ( , 1990Kapur et al ( , 1993Kapur et al ( , 2000, Kadir and Eren (2008), Kadir et al (2010), Eren et al (2004Eren et al ( , 2008, Kaplan et al (2013), Küçükuysal et al (2014). and Kadir et al (2014) of pedogenic palygorskite and calcretes have contributed to the understanding of the major components and genesis as well as the mineralogical and micromorphological aspects of palygorskite associated with calcretes.…”

Micromorphology and formation of pedogenic ooids in calcic soils and petrocalcic horizons

“…Occurrence and genesis of pedogenic ooids and pisoids Durand et al (2010) summarized the micromorphology, interpretations, and terminology of concretionary pedofeatures in calcic soils; a detailed review therefore exceeds the scope of this paper. Further, ooids and pisoids have long been recognized and described in calcic and/or petrocalcic soils or paleosols in India (Khadkikar et al, 2000), the United States (Reeves, 1976;Bachman and Machette, 1977;Hay and Wiggins, 1980;Reheis, 1988;House et al, 2010;and others), Saudi Arabia (Reeves, 1976), Spain (Esteban, 1976;Reeves, 1976;Calvet and Julià, 1983;Alonso-Zarza and Silva, 2002), South Africa (Francis et al, 2012a), Turkey (Kaplan et al, 2013), and other locations around the world. It is also worth noting that some of the described pisoids in these studies could simply be cross-sectional views of clast pendants.…”