naa a22 4500 510756387 CHVBK 20180411083124.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s12594-013-0143-2 doi (NATIONALLICENCE)springer-10.1007/s12594-013-0143-2 New U-Pb ages of zircons in the Owk Shale (Kurnool Group) with reflections on proterozoic porcellanites in India [Elektronische Daten] [M. Bickford, D. Saha, J. Schieber, G. Kamenov, A. Russell, A. Basu] Felsic tuff beds with some presumed sedimentary components were reported from the Owk Shale (Kurnool Group; bearing Neoproterozoic fossils) in the upper part of the sedimentary succession in the Cuddapah basin in India by Saha and Tripathy (2012a). Our optical and SEM petrographic study of three thin sections, however, indicates that the parent samples are sandy mudstones with variable amounts of a felsic volcaniclastic component. New highquality U-Pb (SHRIMP and LA-MC-ICPMS) ages of 133 detrital zircon grains from a sample show that one grain is ca. 1880 Ma, one grain is ca. 3300 Ma, and the ages of the remaining 131 grains fall between 2690 Ma and 2429 Ma, the population averaging 2522 ± 36 Ma. The data indicate that the zircons are detrital grains derived from the ca. 2.5 Ga granitic/gneissic/greenstone basement of the Dharwar cratons that also host minor older Archean enclaves. The single 1880 Ma grain could have come from a ca. 1.9 Ga LIP. In the absence of any younger magmatic zircon, the absolute age of the Owk Shale remains elusive. Geological Society of India, 2013 U-Pb Geochronology nationallicence SHRIMP nationallicence LA-MC-ICPMS nationallicence Detrital Zircon nationallicence Cuddapah nationallicence Proterozoic. Purana. Andhra Pradesh nationallicence Bickford M. Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, 13244-1070, Syracuse, New York, USA aut Saha D. Geological Studies Unit, Indian Statistical Institute, 203 B.T Road, 700108, Kolkata, India aut Schieber J. Department of Geological Sciences, Indiana University, 1001 East 10th Street, 47405, Bloomington, IN, USA aut Kamenov G. Department of Geological Sciences, University of Florida, 241 Williamson Hall, 32611, Gainesville, FL, USA aut Russell A. Schlumberger, 5599 San Felipe, 77056, Houston, TX, USA aut Basu A. Department of Geological Sciences, Indiana University, 1001 East 10th Street, 47405, Bloomington, IN, USA aut Journal of the Geological Society of India Springer India 82/3(2013-09-01), 207-216 0016-7622 82:3<207 2013 82 12594 https://doi.org/10.1007/s12594-013-0143-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12594-013-0143-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bickford M. Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, 13244-1070, Syracuse, New York, USA aut NATIONALLICENCE 700 1- Saha D. Geological Studies Unit, Indian Statistical Institute, 203 B.T Road, 700108, Kolkata, India aut NATIONALLICENCE 700 1- Schieber J. Department of Geological Sciences, Indiana University, 1001 East 10th Street, 47405, Bloomington, IN, USA aut NATIONALLICENCE 700 1- Kamenov G. Department of Geological Sciences, University of Florida, 241 Williamson Hall, 32611, Gainesville, FL, USA aut NATIONALLICENCE 700 1- Russell A. Schlumberger, 5599 San Felipe, 77056, Houston, TX, USA aut NATIONALLICENCE 700 1- Basu A. Department of Geological Sciences, Indiana University, 1001 East 10th Street, 47405, Bloomington, IN, USA aut NATIONALLICENCE 773 0- Journal of the Geological Society of India Springer India 82/3(2013-09-01), 207-216 0016-7622 82:3<207 2013 82 12594 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer