{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T05:48:22Z","timestamp":1747892902931},"reference-count":20,"publisher":"Geological Society of London","issue":"1","license":[{"start":{"date-parts":[[2007,1,1]],"date-time":"2007-01-01T00:00:00Z","timestamp":1167609600000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-002"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["SP"],"published-print":{"date-parts":[[2007,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:p>\n            The lower cap carbonate (Rasthof Formation) overlies Neoproterozoic glacial deposits (Chuos Formation) and is exposed in the Khowarib-Warmquelle area in Northern Namibia. The basal 14.2 m part of the Rasthof Formation (total about 220 m) consists of the carbonate rhythmite. The rhythmite part of the Rasthof Formation contains 1 m cycles of dark- and light-coloured rhythmites. Alizarin-red staining of thin sections and elemental mapping of polished samples indicate that the dark-coloured parts are rich in calcite, whereas the light-coloured parts are dolomite-rich. On a 1 cm scale, a reddish clay layer is intercalated in each calcite rich dark-coloured rhythmite part. These cycles of reddish clays as well as some associated major turbidites can be well correlated between columns up to about 20 km distance. Furthermore, at one locality (K4), rip-up clasts occur in a turbidite bed. Their lithology consists of dark- and light-coloured rhythmite and a reddish clay layer and can be judged to have been derived from underlying horizons. Because the clasts are elastically deformed, it is strongly suggested that the difference in lithology observed within the basal part of the Rasthof Formation existed when clasts were ripped-up shortly after sedimentation. This suggests that the cycle involving dolomite is synsedimentary, and not a diagenetic feature. Direct precipitation of dolomite does not occur in present day open marine seawater. Hurtgen\n            <jats:italic>et al.<\/jats:italic>\n            (2002) suggest that seawater was depleted in sulphate after Neoproterozoic glaciation. It is proposed here that some possible depositional models of cycles that consist of calcite-rich and dolomite-rich parts as well as reddish clay beds in rhythmites of the Rasthof cap carbonate.\n          <\/jats:p>","DOI":"10.1144\/sp286.7","type":"journal-article","created":{"date-parts":[[2007,12,13]],"date-time":"2007-12-13T16:54:24Z","timestamp":1197564864000},"page":"103-113","source":"Crossref","is-referenced-by-count":6,"title":["Calcite\u2013dolomite cycles in the Neoproterozoic Cap carbonates, Otavi Group, Namibia"],"prefix":"10.1144","volume":"286","author":[{"given":"B.","family":"Tojo","sequence":"first","affiliation":[{"name":"Faculty of Education, Gifu University, 1-1 Yanagito, Gifu City 501-1193, Japan (e-mail: )"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"N.","family":"Katsuta","sequence":"additional","affiliation":[{"name":"Graduate School of Environmental Studies, Nagoya University, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M.","family":"Takano","sequence":"additional","affiliation":[{"name":"Graduate School of Environmental Studies, Nagoya University, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S.","family":"Kawakami","sequence":"additional","affiliation":[{"name":"Faculty of Education, Gifu University, 1-1 Yanagito, Gifu City 501-1193, Japan (e-mail: )"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"T.","family":"Ohno","sequence":"additional","affiliation":[{"name":"The Kyoto University Museum, Kyoto University, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1881","published-online":{"date-parts":[[2007,10,26]]},"reference":[{"key":"e_1_3_2_2_1","first-page":"7","volume-title":"16th International Sedimentological Congress Abstract Volume","author":"Allen P. A.","year":"2002","unstructured":"Allen P. A., Bowring S. A., Leather J., Brasier M., Cozzi A., Grotzinger J. P., McCarron G., Amthor J.Chronology of Neoproterozoic glaciations: New insights from Oman200216th International Sedimentological Congress Abstract VolumeJohannesburgInternational Association of Sedimentologists78"},{"key":"e_1_3_2_3_1","first-page":"13219","article-title":"Geochronological constraints on terminal Neoproterozoic events and the rise of metazoans","volume":"5","author":"Bowring S.","year":"2003","unstructured":"Bowring S., Myrow P., Landing E., Ramezani J., Grotzinger J.Geochronological constraints on terminal Neoproterozoic events and the rise of metazoansGeophysical Research Abstracts2003513219","journal-title":"Geophysical Research Abstracts"},{"key":"e_1_3_2_4_1","volume-title":"Tracers in the Sea","author":"Broecker W. S.","year":"1982","unstructured":"Broecker W. S., Peng T.-H.Tracers in the Sea1982New YorkColumbia UniversityPalisades"},{"doi-asserted-by":"publisher","key":"e_1_3_2_5_1","DOI":"10.1016\/0012-821X(79)90061-X"},{"doi-asserted-by":"publisher","key":"e_1_3_2_6_1","DOI":"10.2475\/ajs.300.5.347"},{"doi-asserted-by":"publisher","key":"e_1_3_2_7_1","DOI":"10.1029\/2001GC000244"},{"key":"e_1_3_2_8_1","volume-title":"Earth's Pre-Pleistocene Glacial Record","author":"Hambrey M. J.","year":"1981","unstructured":"Hambrey M. J., Harland W. B.Earth's Pre-Pleistocene Glacial Record1981CambridgeCambridge University Press"},{"key":"e_1_3_2_9_1","first-page":"77","article-title":"A preliminary note on a revised subdivision and regional correlation of the Otavi Group based on glaciogenic diamictites and associated cap dolostones","volume":"11","author":"Hoffmann K.-H.","year":"1996","unstructured":"Hoffmann K.-H., Prave A. R.A preliminary note on a revised subdivision and regional correlation of the Otavi Group based on glaciogenic diamictites and associated cap dolostonesGeological Survey of Namibia Communications1996117782","journal-title":"Geological Survey of Namibia Communications"},{"doi-asserted-by":"publisher","key":"e_1_3_2_10_1","DOI":"10.1130\/G20519.1"},{"key":"e_1_3_2_11_1","first-page":"47","article-title":"Precise U\u2013Pb zircon ages for early Damaran magmatism in the Summas Mountains and Welwitschia Inlier, northern Damara belt, Namibia","volume":"11","author":"Hoffman P. F.","year":"1996","unstructured":"Hoffman P. F., Hawkins D. P., Isachsen C. E., Bowring S. A.Precise U\u2013Pb zircon ages for early Damaran magmatism in the Summas Mountains and Welwitschia Inlier, northern Damara belt, NamibiaGeological Survey of Namibia Communications1996114752","journal-title":"Geological Survey of Namibia Communications"},{"doi-asserted-by":"publisher","key":"e_1_3_2_12_1","DOI":"10.1126\/science.281.5381.1342"},{"doi-asserted-by":"publisher","key":"e_1_3_2_13_1","DOI":"10.1046\/j.1365-3121.2002.00408.x"},{"doi-asserted-by":"publisher","key":"e_1_3_2_14_1","DOI":"10.1016\/S0012-821X(02)00804-X"},{"key":"e_1_3_2_15_1","article-title":"A method to detect rhythm of lamination in Precambrian sedimentary rocks: evidences for environmental variation during a glacial to interglacial period in Neoproterozoic","author":"Katsuta N.","year":"2005","unstructured":"Katsuta N., Tojo B., Kawakami S., Takano M., Ohno T., Kumazawa M.A method to detect rhythm of lamination in Precambrian sedimentary rocks: evidences for environmental variation during a glacial to interglacial period in NeoproterozoicIGCP493 Prato Meeting Extended Abstract2005","journal-title":"IGCP493 Prato Meeting Extended Abstract"},{"doi-asserted-by":"publisher","key":"e_1_3_2_16_1","DOI":"10.1073\/pnas.94.13.6600"},{"doi-asserted-by":"publisher","key":"e_1_3_2_17_1","DOI":"10.1130\/0091-7613(1998)026<1059:TOFNG>2.3.CO;2"},{"key":"e_1_3_2_18_1","first-page":"51","volume-title":"The Proterozoic Biosphere.","author":"Kirschvink J. K.","year":"1992","unstructured":"Kirschvink J. K., Schopf J. W., Klein C.Late Proterozoic low-latitude global glaciation: the snowball earthThe Proterozoic Biosphere.1992CambridgeCambridge University Press5152"},{"doi-asserted-by":"publisher","key":"e_1_3_2_19_1","DOI":"10.1002\/9781444314175.ch8"},{"doi-asserted-by":"publisher","key":"e_1_3_2_20_1","DOI":"10.1016\/S0301-9268(03)00079-2"},{"doi-asserted-by":"publisher","key":"e_1_3_2_21_1","DOI":"10.5408\/0022-1368-20.3.107"}],"container-title":["Geological Society, London, Special Publications"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.lyellcollection.org\/doi\/pdf\/10.1144\/SP286.7","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,7,24]],"date-time":"2024-07-24T02:19:39Z","timestamp":1721787579000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.lyellcollection.org\/doi\/10.1144\/SP286.7"},"secondary":[{"URL":"https:\/\/pubs.geoscienceworld.org\/books\/book\/1658\/chapter\/107470669\/calcitedolomite-cycles-in-the-neoproterozoic-cap","label":"geoscienceworld"},{"URL":"https:\/\/pubs.geoscienceworld.org\/UrlRedirectHandler.ashx?routename=books&chapterdoi=10.1144\/SP286.7&request=chapter","label":"geoscienceworld"}]},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,1]]},"references-count":20,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2007,12,13]]},"published-print":{"date-parts":[[2007,1]]}},"alternative-id":["10.1144\/SP286.7"],"URL":"https:\/\/doi.org\/10.1144\/sp286.7","relation":{},"ISSN":["0305-8719","2041-4927"],"issn-type":[{"type":"print","value":"0305-8719"},{"type":"electronic","value":"2041-4927"}],"subject":[],"published":{"date-parts":[[2007,1]]}}}