de.pangaea.dataset819840 und dataset PANGAEA

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https://www.pangaea.de/ information pointOfContact 2026-06-15T18:59:09Z https://doi.pangaea.de/10.1594/PANGAEA.819840 1981-01-01 publication https://doi.org/10.1594/PANGAEA.819840 Riech, Volkher author PANGAEA

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https://www.pangaea.de/ information publisher tableDigital Supplement to: Riech, Volkher (1981): Siliceous sediments from the Nauru Basin: Diagenetic alteration of biogenic opal and authigenesis of silica and silicates. In: Larson, RL; Schlanger, SO; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 61, 523-531, https://doi.org/10.2973/dsdp.proc.61.109.1981 This study deals with the mineralogical variability of siliceous and zeolitic sediments, porcellanites, and cherts at small intervals in the continuously cored sequence of Deep Sea Drilling Project Site 462. Skeletal opal is preserved down to a maximum burial depth of 390 meters (middle Eocene). Below this level, the tests are totally dissolved or replaced and filled by opal-CT, quartz, clinoptilolite, and calcite. Etching of opaline tests does not increase continously with deeper burial. Opal solution accompanied by a conspicuous formation of authigenic clinoptilolite has a local maximum in Core 16 (150 m). A causal relationship with the lower Miocene hiatus at this level is highly probable. Oligocene to Cenomanian sediments represent an intermediate stage of silica diagenesis: the opal-CT/quartz ratios of the silicified rocks are frequently greater than 1, and quartz filling pores or replacing foraminifer tests is more widespread than quartz which converted from an opal-CT precursor. As at other sites, there is a marked discontinuity of the transitions from biogenic opal via opal-CT to quartz with increasing depth of burial. Layers with unaltered opal-A alternate with porcellanite beds; the intensity of the opal-CT-to-quartz transformation changes very rapidly from horizon to horizon and obviously is not correlated with lithologic parameters. The silica for authigenic clinoptilolite was derived from biogenic opal and decaying volcanic components. completed Riech, Volkher principalInvestigator DSDP Deep Sea Drilling Project theme 1995-01-01 creation PANGAEA

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https://www.pangaea.de/ information pointOfContact copyright copyright CC-BY-3.0: Creative Commons Attribution 3.0 Unported textTable und geoscientificInformation 165.0305 165.0317 7.2375 7.2417 1978-05-28T00:00:00 1978-06-09T00:00:00 - = no data, + = least abundant, ++++ = most abundant, ? = unknowns. Event label thematicClassification Sample code/label thematicClassification DSDP/ODP/IODP sample designation Lithology/composition/facies thematicClassification X-ray diffraction (XRD); Of silicified rock Main Lithology thematicClassification X-ray diffraction (XRD); Calcareous Main Lithology thematicClassification X-ray diffraction (XRD); Siliceous Quartz thematicClassification X-ray diffraction (XRD); Early Diagenetic - thematicClassification X-ray diffraction (XRD); Opal-CT/quartz ratio - thematicClassification X-ray diffraction (XRD); Stage of opal-CT - quartz transformation: + = small amount of opal-CT starts to transform into quartz, ++++ = all opal-CT transformed into quartz text/tab-separated-values unknown https://doi.pangaea.de/10.1594/PANGAEA.819840?format=textfile download dataset The data set was checked for completeness, correctness, and consistency of metainformation. Validity of used methods was checked and - if applicable - precision and range of data. EVENT LABEL: 61-462 * LATITUDE: 7.237500 * LONGITUDE: 165.030500 * DATE/TIME: 1978-05-28T00:00:00 * ELEVATION: -5181.0 m * PENETRATION: 617 m * RECOVERY: 386 m * CAMPAIGN: Leg61 * BASIS: Glomar Challenger * METHOD/DEVICE: Drilling/drill rig 70 cores; 627.4 m cored; 0 m drilled; 61.5 % recovery 1978-05-28T00:00:00 EVENT LABEL: 61-462A * LATITUDE: 7.241700 * LONGITUDE: 165.031700 * DATE/TIME: 1978-06-09T00:00:00 * ELEVATION: -5177.0 m * PENETRATION: 1068.5 m * RECOVERY: 344 m * CAMPAIGN: Leg61 * BASIS: Glomar Challenger * METHOD/DEVICE: Drilling/drill rig 90 cores; 619.5 m cored; 14.5 m drilled; 55.5 % recovery 1978-06-09T00:00:00