Diagenesis of siliceous oozes—I. Chemical controls on the rate of opal-A to opal-CT transformation—an experimental study

Kastner, Miriam; Keene, J. B.; Gieskes, Joris M.

doi:10.1016/0016-7037(77)90099-0

Cited by 435 publications

(305 citation statements)

References 40 publications

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“…Variable dissolution of silica in the uppermost sediment prior to burial. The preservation of radiolarian tests is affected by the Eh and pH of the interstitial waters (e.g., Johnson, 1975;Kastner et al, 1977;Riech and von Rad, 1979;Kastner and Gieskes, 1983), and varies among different radiolarian taxa (Takahashi, 1987). Therefore, enhancement of silica preservation could result from several factors, including the presence of reducing organic material or an increase in the CO 2 content of bottom waters (e.g., De Wever, 1982).…”

Section: Alternations Of Radiolarite and Claystonementioning

confidence: 99%

“…Therefore, complete utilization of this silica by dissolution, migration, and precipitation would be inadequate to produce chert layers thicker than 1 cm. The high clay content will also slow the rate of silica reprecipitation as opal-CT (Kastner et al, 1977).…”

Section: Inhibition Of Silicificationmentioning

confidence: 99%

“…Clay inhibits silica recrystallization of biogenic opal-A to diagenetic opal-CT and can preserve radiolarians during early diagenesis, whereas carbonate drives the reaction faster to quartz (Kastner et al, 1977). Discontinuous or coalescing porcellanite/chert nodules form at semi-regular stratigraphic intervals; this semi-regular spacing in otherwise mostly homogeneous sediments may be the result of centers of silicification lowering the concentration of dissolved silica in the surrounding sediment, thereby inhibiting nucleation in proximity to earlier-formed bands or nodules.…”

Section: Deep-ocean Pacific Radiolaritesmentioning

confidence: 99%

“…The abundance of clay within these radiolarites has probably inhibited the process of silicification (Kastner et al, 1977). A large portion of this clay consists of Fe-smectites, and it is conceivable that with diagenesis at higher temperatures, the Fe-smectites may be transformed, releasing Fe and Silica.…”

Section: Deep-ocean Pacific Radiolaritesmentioning

confidence: 99%

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Jurassic through Early Cretaceous Sedimentation History of the Central Equatorial Pacific and of Sites 800 and 801

Ogg¹,

Stattegger²,

Behl³

1992

Proceedings of the Ocean Drilling Program

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Sedimentation in the central Pacific during the Jurassic and Early Cretaceous was dominated by abundant biogenic silica. A synthesis of the stratigraphy, lithology, petrology, and geochemistry of the radiolarites in Sites 801 and 800 documents the sedimentation processes and trends in the equatorial central Pacific from the Middle Jurassic through the Early Cretaceous. Paleolatitude and paleodepth reconstructions enable comparisons with previous DSDP sites and identification of the general patterns of sedimentation over a wide region of the Pacific.Clayey radiolarites dominated sedimentation on Pacific oceanic crust within tropical paleolatitudes from at least the latest Bathonian through Tithonian. Radiolarian productivity rose to a peak within 5° of the paleoequator, where accumulation rates of biogenic silica exceeded 1000 g/cm 2 /m.y. Wavy-bedded radiolarian cherts developed in the upper Tithonian at Site 801 coinciding with the proximity of this site to the paleoequator. Ribbon-bedding of some radiolarian cherts exposed on Pacific margins may have formed from silicification of radiolarite deposited near the equatorial high-productivity zone where radiolarian/clay ratios were high. Silicification processes in sediments extensively mixed by bioturbation or enriched in clay or carbonate generally resulted in discontinuous bands or nodules of porcellanite or chert, e.g., a "knobby" radiolarite. Ribbon-bedded cherts require primary alternations of radiolarian-rich and clay-rich layers as an initial structural template, coupled with abundant biogenic silica in both layers. During diagenesis, migration of silica from clay-rich layers leaves radiolarian "ghosts" or voids, and the precipitation in adjacent radiolarite layers results in silicification of the inter-radiolarian matrix and infilling of radiolarian tests. Alternations of claystone and clay-rich radiolarian grainstone were deposited during the Callovian at Site 801 and during the Berriasian-Valanginian at Site 800, but did not silicify to form bedded chert.Carbonate was not preserved on the Pacific oceanic floor or spreading ridges during the Jurassic, perhaps due to an elevated level of dissolved carbon dioxide. During the Berriasian through Hauterivian, the carbonate compensation depth (CCD) descended to approximately 3500 m, permitting the accumulation of siliceous limestones at near-ridge sites. Carbonate accumulation rates exceeded 1500 g/cm 2 /m.y. at sites above the CCD, yet there is no evidence of an equatorial carbonate bulge during the Early Cretaceous. In the Barremian and Aptian, the CCD rose, coincident with the onset of mid-plate volcanic activity.Abundance of Fe and Mn and the associated formation of authigenic Fe-smectite clays was a function of proximity to the spreading ridges, with secondary enrichments occurring during episodes of spreading-center reorganizations. Callovian radiolarite at Site 801 is anomalously depleted in Mn, which resulted either from inhibited precipitation of Mn-oxides by lower pH of interstitial waters in...

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Section: Alternations Of Radiolarite and Claystonementioning

confidence: 99%

Section: Inhibition Of Silicificationmentioning

confidence: 99%

Section: Deep-ocean Pacific Radiolaritesmentioning

confidence: 99%

Section: Deep-ocean Pacific Radiolaritesmentioning

confidence: 99%

See 2 more Smart Citations

Jurassic through Early Cretaceous Sedimentation History of the Central Equatorial Pacific and of Sites 800 and 801

Ogg¹,

Stattegger²,

Behl³

1992

Proceedings of the Ocean Drilling Program

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“…Diagenesis then silicified limestones and chertified radiolarian oozes, creating of a full range of various lithologies between chalks and cherts. The evolution of siliceous biogenic oozes and formation of cherts, and the role of various amounts of clays and carbonate, as well as the role of time in the mineralogical composition of cherts, have been discussed by Lancelot (1973), Wise and Weaver (1974), Kastner et al (1977), and Pisciotto (1981) and references therein.…”

Section: Albian-cenomanian Biogenic Sedimentationmentioning

confidence: 99%

Site 800

1990

Proceedings of the Ocean Drilling Program

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Silicon pools in human impacted soils of temperate zones

Vandevenne

Barão

Ronchi

et al. 2015

Global Biogeochemical Cycles

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Besides well-known effects of climate and parent material on silicate weathering the role of land use change as a driver in the global silicon cycle is not well known. Changes in vegetation cover have altered reservoirs of silicon and carbon in plants and soils. This has potential consequences for plant-Si availability, agricultural yields, and coastal eutrophication, as Si is a beneficial element for many crop plants and an essential nutrient for diatom growth. We here examined the role of sustained and intensive land use and human disturbance on silicon (Si) pool distribution in soils with similar climatological and bulk mineralogical characteristics. We show that land use impacts both biogenic and nonbiogenic Si pools. While biogenic Si strongly decreases along the land use change gradient (from forest to croplands), pedogenic silica fractions (e.g. pedogenic clays) increase in topsoils with a long duration of cultivation and soil disturbance. Our results suggest that nonbiogenic Si pools might compensate for the loss of reactive biogenic silicon in temperate zones.

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Diagenesis of siliceous oozes—I. Chemical controls on the rate of opal-A to opal-CT transformation—an experimental study

Cited by 435 publications

References 40 publications

Jurassic through Early Cretaceous Sedimentation History of the Central Equatorial Pacific and of Sites 800 and 801

Jurassic through Early Cretaceous Sedimentation History of the Central Equatorial Pacific and of Sites 800 and 801

Site 800

Silicon pools in human impacted soils of temperate zones

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