U.S. Geological Survey standards—II. First compilation of data for the new U.S.G.S. rocks

Flanagan, F.J.

doi:10.1016/0016-7037(69)90094-5

Cited by 442 publications

(56 citation statements)

References 138 publications

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“…The average deviation is about • 5% at each level of fluoride content. The values in Table 1 for this method are in excellent agreement with values reported by Ingrain (1970), and in good agreement with the consensus values reported Flanagan (1969).…”

Section: Apparatussupporting

confidence: 89%

Flouride Content of Clay Minerals and Argillaceous Earth Materials

Thomas

Glass

White

et al. 1977

Clays and clay miner.

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A reliable method, utilizing a fluoride ion-selective electrode, is described for the determination of fluoride in clays and shales. Interference by aluminum and iron is minimal. The reproducibility of the method is about ___5~0 at different levels of fluoride concentration.Data are presented for various clay minerals and for the <2-/~m fractions of marine and nonmarine clays and shales. Fluoride values range from 44 ppm (0.0044%) for nontronite from Colfax, WA, to 51,800 ppm (5.18%) for hectorite from Hector, CA. In general, clays formed under hydrothermal conditions are relatively high in fluoride content, provided the hydrothermal waters are high in fluoride content. Besides hectorite, dickite from Ouray, CO, was found to contain more than 50 times as much fluoride (6700 ppm) as highly crystalline geode kaolinite (125 ppm). The clay stratum immediately overlying a fluorite mineralized zone in southern Illinois was found to have a higher fluoride content than the same stratum in a nonmineralized zone approximately 1 mile away. Nonmarine shales in contact with Australian coals were found to be lower in fluoride content than were marine shales in contact with Illinois coals.It is believed that, in certain instances, peak shifts on DTA curves of similar clay minerals are the result of significant differences in their fluoride content.

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Section: Apparatussupporting

confidence: 89%

Flouride Content of Clay Minerals and Argillaceous Earth Materials

Thomas

Glass

White

et al. 1977

Clays and clay miner.

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“…U content was analyzed by fission-track method (Nishimura, 1970). The results seem to be reasonable comparing with the data compiled by Flanagan (1969).…”

Section: Samplessupporting

confidence: 69%

Rare-earth and trace elements of basaltic rocks of Ikuno Group, Japan.

Nishimura

Ikeda

Morishita³

1976

J. Japan. Assoc. Min. Petr. Econ. Geol.

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Seven rare-earth elements (La, Ce, Sm, Eu, Tb, Yb and Lu) , Ba, Co, Cr, Hf, Sc and Th have been determined by nondestractive neutron activation analysis and U by fission track method on the basaltic rocks of meso-volcanic complex in Ikuno group, Hyogo Prefecture, Japan. The trace element abundances are discussed in terms of the petrological problems, especially, the origin of magma. The volcanic complex of Ikuno group consists of rhyolite, andesite, alteration of black shale and tuff, and dellenite. The basaltic rocks are found in the Ikuno group as sheet and dykes which intruded into Ikuno group. The basaltic sheet is alkalic rock and these dykes are high alumina basalt series.

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“…Trace and rare earth elements were analyzed by instrumental neutron activation (INA) by Activation Laboratories Ltd., Toronto, Canada. Interlaboratory standard rocks G-2 and MRG-1 were run as unknowns,and the results were compared to accepted values (Flanagan, 1969;Perrault et al, 1984, as listed in Govindaraju, 1989. Also, the concentrations of REE were measured on whole rocks and illites from the…”

Section: Samples and Methodsmentioning

confidence: 99%

Origin of the Mg-Smectite at the Cretaceous/Tertiary (K/T) Boundary at Stevns Klint, Denmark

Elliott

1993

Clays and clay miner.

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Abstract--The clay mineralogy and major element geochemistry of four distinct layers within the Cretaceous/Tertiary (K/T) boundary marl (i.e., II, IIIa, IIIb, and IV) at Stevns Klint, Denmark, including "impact layer" (layer IIIa), were examined, and there was not a marked change in the clay mineralogy throughout this K/T boundary marl. A magnesium smectite (i.e., Mg-smectite) was the predominant clay mineral at the K/T boundary not only at Stevns Klint and at Nye Klov; it was also found to be the predominant clay mineral in the K/T boundary at Karlstrup Quan-y. In addition, Mg-smectite was found in a smectitic marl 32 meters below the K/T boundary at the Limhamn Quarry (near Malm6, Sweden), and it did not have anomalous concentrations of iridium or other siderophile trace elements. Given its occurrence in a Maastrichtian marl, it is therefore argued that the Mg-smectite is not derived from meteorite impact.The rare earth element (REE) signatures of the Mg-smectites ranged from being comparable to the North American Shale Standard (NASC) to being one-half an order of magnitude depleted relative to NASC. One Mg-smectite collected from layer IIIb, immediately above the "impact/red layer," was depleted in REE by one order of magnitude relative to NASC, and these levels of REE are comparable to those of smectite and illite/smectite (I/S) formed authigenically in bentonites and K-bentonites, respectively. Thus, the REE data suggest this Mg-smectite in all likelihood was formed authigenically from a glassy precursor. The presence of the low levels of REE of the Mg-smectite in the layer IIIb has no particular significance other than to suggest that this Mg-smectite separate was the least contaminated with illite or apatite having higher REE levels. With better separation, the other Mg-smectites would be expected to have comparably low levels of REE. Given the presence of the Mg-smectite throughout the K/T boundary and in Maastrichtian and Danian marls, the Mg-smectite is thought to be of volcanic origin. However, is not certain whether the Mg-smectite formed from volcanic glass deposited at the K/T boundary or whether it was formed from volcanic glass as young as late Cretaceous.

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U.S. Geological Survey standards—II. First compilation of data for the new U.S.G.S. rocks

Cited by 442 publications

References 138 publications

Flouride Content of Clay Minerals and Argillaceous Earth Materials

Flouride Content of Clay Minerals and Argillaceous Earth Materials

Rare-earth and trace elements of basaltic rocks of Ikuno Group, Japan.

Origin of the Mg-Smectite at the Cretaceous/Tertiary (K/T) Boundary at Stevns Klint, Denmark

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