Phanerozoic Oolitic Ironstones--Geologic Record and Facies Model

Houten, Franklyn B. Van; Bhattacharyya, D. P.

doi:10.1146/annurev.ea.10.050182.002301

Cited by 124 publications

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“…The occurrence of berthierine and glauconite in sedimentstarved condensed sequences (Bhattacharyya, 1980;Gygi, 1981;Odin and Matter, 1981), their common association with detrital and carbonate rocks, and their coincidence with coast-parallel zones of kaolinite and smectite sedimentation, respectively, all point to a common genetic process acting on different detrital precursors to produce berthierine and glauconite (Bhattacharyya, 1980;Van Houten and Bhattacharyya, 1982).…”

Section: Resultsmentioning

confidence: 99%

“…The latter have been interpreted to possess a mechanical accretion fabric, in contrast to the radial crystallization fabric of the Salt Lake-type ooids (Sandberg, 1975). A dominant siliciclastic sedimentary association and facies sequences of the oolitic ironstones vitiate the calcareous oolite replacement hypothesis as the principal mode of formation of ferriferrous ooids (Bhattacharyya, 1980;Bradshaw et al, 1980;Van Houten and Bhattacharyya, 1982). Moreover, radial fabric, common in carbonate oolites (Sandberg, 1975;Davies and Martin, 1976), has not been reported in the oolitic ironstones; neither have unequivocal carbonate ooids partially replaced by berthierine, even in thick and extensive ironstone deposits as young in age as Pliocene in the Kerch peninsula of the Soviet Union (Sokolova, 1964).…”

Section: Introductionmentioning

confidence: 99%

“…A facies model and petrographic evidence derived from the studies of a number of Phanerozoic oolitic ironstones (Bhattacharyya, 1980;Van Houten and Bhattacharyya, 1982) suggest that early diagenetic transformation of detrital kaolinite, both in the matrix and the ooids of the ironstone precursor (i.e., oolitic, ferruginous sediment prior to diagenesis), is a probable mode of berthierine formation.…”

Section: Introductionmentioning

confidence: 99%

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Origin of Berthierine in Ironstones

Bhattacharyya

1983

Clays and clay miner.

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Abstract--To test the hypothesis that berthierine in oolitic ironstones formed by diagenetic transformation of detrital kaolinite, laboratory experiments simulating the early diagenetic conditions were conducted. Representative sets of the initial sediment were prepared in distilled water and artificial seawater suspensions by mixing 4-13 g/liter kaolinite with Fe(OH)a precipitated from 0.1-0.3 M FeClz solutions. ~NazS204 was added to the suspensions as a reducing agent, and inert Nz atmospheres were used to maintain the required Eh between + 100 and -400 mV. The pH of the suspensions was controlled between 8 and 5 with dilute HC1. Within 300 days, the iron content of the bulk kaolinite in the seawater suspensions progressively increased from 0.18 to 2.44% at pH = 7 and Eh between -250 and -350 mV. Energy dispersive X-ray analyses of individual clay platelets in the final products showed progressive, temporal increase in Fe, and concomitant decrease in AI and Si. X-ray powder diffractometry revealed small d (001)-d(002) shifts, marked intensity reversals of (001) and (002) reflections, and the development of additional characteristic berthierine reflections with time. These data suggest progressive transformation of kaolinite to berthierine. Microprobe analyses of natural berthierine in oolitic ironstones also showed parallel patterns, which substantiate such progressive transformation from the margin toward the core of the ooids. The transformation did not take place in distilled water. The addition of Mg 2 § to the distilled water suspensions, however, promoted the transformation.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Origin of Berthierine in Ironstones

Bhattacharyya

1983

Clays and clay miner.

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“…These samples were previously the target of a microprobe study (34). The University of Cincinnati samples were supplemented with samples from the Red Mountain Formation, given that this unit has been extensively studied and is considered a 'type' ironstone deposit (35). Precambrian ironstones were newly collected for this study.…”

Section: Methodsmentioning

confidence: 99%

Low Mid-Proterozoic atmospheric oxygen levels and the delayed rise of animals

Planavsky

Reinhard

Wang

et al. 2014

Science

622

469

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Low oxygen limited the rise of animals Oxygen levels in Earth's early atmosphere had an important influence on the evolution of complex life. Planavsky et al. analyzed the isotopic signature of chromium in sedimentary rocks from across the globe—a proxy for past oxygen levels. Oxygen levels in the mid-Proterozoic (1.6 billion to 900 million years ago) were very low: less than 0.1% of the modern atmosphere. These low levels were probably below the minimum oxygen requirements for the earliest animals, delaying their emergence and diversification. Science , this issue p. 635

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“…Iron ooids are a relatively rare component of sedimentary rocks; they usually occur as the main constituents of thin stratigraphic intervals (ooidal ironstones) with wide chronologic (Precambrian to Cenozoic) and geographic (America, Europe, Asia, Africa, Australia) distribution (Van Houten and Bhattacharyya 1982;Dahanayake and Krumbein 1986;Van Houten 1990). Classic examples are the Toarcian-Aalenian "Minette ooidal ironstones" (Bubenicek 1971) and the Bajocian "Oolithe ferrugineuse de Bayeux" (Fürsich 1971) in the Jurassic successions of the Paris Basin.…”

Section: Introductionmentioning

confidence: 99%