Dinoflagellate Age of Middle Jurassic-Early Cretaceous Sediments in the Blake-Bahama Basin

Habib, Daniel; Drugg, Warren S.

doi:10.2973/dsdp.proc.76.126.1983

Cited by 40 publications

(59 citation statements)

References 18 publications

(22 reference statements)

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“…In contrast to the ubiquitous oxygenation of the Pacific sediments, the Atlantic pelagic carbonates have preserved Late Jurassic through Early Cretaceous organic microfossils, enabling development of a regional high-resolution dinoflagellate stratigraphy Habib and Drugg, 1983), and display frequent intervals of laminated sedimentation with elevated organic-carbon content during the Valanginian through Aptian (e.g., Lancelot et al, 1972;Robertson and Bliefnick, 1983;Ogg et al, 1987;Huang, 1991).…”

Section: Bottom Water Oxygenationmentioning

confidence: 99%

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: Bottom Water Oxygenationmentioning

confidence: 99%

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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“…The genus is emended to incorporate the paratabulation formula as revised by Habib (Habib & Drugg, 1983) for D. apicopaucicum and observed by the present author on D. jubatum and D. augustum sp. nov.…”

Section: Partially Emended Diagnosismentioning

confidence: 99%

“…Previous interpretations of archaeopyle type in Druggidium have indicated a two-paraplate precingular archaeopyle, a compound biplacoid operculum often remaining adherent to the cingular paraplate series (Habib, 1973;Habib & Drugg, 1983).…”

Section: Archaeopyle Charactermentioning

confidence: 99%

“…3, figs. 1-2 of Habib & Drugg, 1983). Division Pyrrophyta Pascher, 1914Class Dinophyceae Fritsch, 1929 Genus Druggidium Habib, 1973 emend.…”

Section: Druggidium Jubatummentioning

confidence: 99%

“…The paratabulation formula, as given by Habib (1973, p. 49) was 3'-4', Oa, 6 , 6c, 6 ' , l p , 1"". This has since been modified to pr, 4', 4a, 7', 7c, 6 ' , lp, l"", 2s (Habib in Habib & Drugg, 1983). This revision of the epicystal paraplating was based on observations of paratype material using the S.E.M.…”

Section: Introductionmentioning

confidence: 99%

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Archaeopyle variability in Early Cretaceous dinocysts of the partiform gonyaulacoid genus <i>Druggidium</i> Habib

Harding

1986

J. Micropalaeontol.

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ABSTRACT-Scanning electron microscope (S.E .M.) observation techniques have enabled paratabulation formulae to be elucidated (in both Kofoidian and Taylor-Evitt notation) for the partiform gonyaulacoid dinocyst genus Druggidium Habib. Archaeopyle variability within the species of this genus is highlighted, further emphasising the uncertainties concerning the taxonomic significance of archaeopyle type. The genus Druggidium is therefore emended, as is the species D. jubatum Duxbury. One new species, D. augustum, is described.

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A dinocyst assemblage from the middle member (lower Kimmeridgian—Tithonian) of the Jhuran formation, Kachchh, India

Kumar¹

1986

Review of Palaeobotany and Palynology

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Dinoflagellate Age of Middle Jurassic-Early Cretaceous Sediments in the Blake-Bahama Basin

Cited by 40 publications

References 18 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

Archaeopyle variability in Early Cretaceous dinocysts of the partiform gonyaulacoid genus <i>Druggidium</i> Habib

A dinocyst assemblage from the middle member (lower Kimmeridgian—Tithonian) of the Jhuran formation, Kachchh, India

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Dinoflagellate Age of Middle Jurassic-Early Cretaceous Sediments in the Blake-Bahama Basin

Cited by 40 publications

References 18 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

Archaeopyle variability in Early Cretaceous dinocysts of the partiform gonyaulacoid genus &lt;i&gt;Druggidium&lt;/i&gt; Habib

A dinocyst assemblage from the middle member (lower Kimmeridgian—Tithonian) of the Jhuran formation, Kachchh, India

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Archaeopyle variability in Early Cretaceous dinocysts of the partiform gonyaulacoid genus <i>Druggidium</i> Habib