Genetic significance of Co, Cr, Ni, Sc and V content of andesites

Taylor, Stuart Ross; Kaye, Maureen; White, A. J. R.; Duncan, A. R.; Ewart, A.

doi:10.1016/0016-7037(69)90144-6

Cited by 87 publications

(18 citation statements)

References 15 publications

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“…H = 10% hornblende fractionation assuming initial Ti =similar and less than one. This will be true of most fractionating assemblages under oxidizing conditions until the onset of magnetite or hornblende fractionation, which will strongly deplete both Ti and V [16,17,23,[24][25][26]. The effects of magnetite fractionation are shown in Fig.…”

Section: Partial Melting and Fractional Crystallizationmentioning

confidence: 99%

“…2C). There is minor overlap with MORB ratios (20)(21)(22)(23)(24)(25)(26)(27) when V is less than 350 ppm; however, suites of related samples with a range of Ti and V abundances will display the distinctive "chondritic" trend that clearly distinguishes arc tholeiites from MORB. The more evolved rocks of the arc tholeiite suite (SiO 2 > 58-60%) show the effects of titanomagnetite fractionation: sudden drastic reduction in Ti and V abundances and increasing Ti/V ratios.…”

Section: Island Arc Lavasmentioning

confidence: 99%

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Ti-V plots and the petrogenesis of modern and ophiolitic lavas

Shervais

1982

Earth and Planetary Science Letters

2,031

960

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Plots of Ti vs. V for many modern volcanic rock associations are diagnostic of tectonic setting and can be used to determine possible tectonic settings of ophiolites as well. The basis of this plot is the variation in the crystal/liquid partition coefficients for vanadium, which range with increasing oxygen fugacity from > 1 to << 1. Since the partition coefficients for Ti are almost always << 1, the depletion of V relative to Ti is a function of the fo2 of the magma and its source, the degree of partial melting, and subsequent fractional crystallization. Volcanic rocks from modern island arcs have Ti/V ratios of ~20, except for calc-alkaline volcanics which show the effects of magnetite fractionation. MORB and continental flood basalts have Ti/V ratios of about 20-50 and alkaline rocks have Ti/V generally >50. Back-arc basin basalts may have either arc-like or MORB-like Ti/V ratios, and sample suites from single back-arc basins may have Ti/V ratios ranging from 10 to 50. This range in Ti/V ratios in samples from a restricted geographical area may be diagnostic of the back-arc setting. The Ti/V plot is applied here to published data on ophiolites from a variety of postulated settings and in general supports the conclusions of previous investigators. Ophiolites from the western Mediterranean (Corsica, northern Apennines) and the "lower" Karmoy volcanics have Ti/V trends similar to MORB; the "upper" Karmo'y volcanics have alkaline Ti/V ratios. Lavas and tonalites in the Papuan ultramafic belt, the high-Mg andesites of Cape Vogel, and the upper pillow lavas at Troodos all have Ti/V ratios < 20, consistent with formation in an island arc setting. More specific evaluation of the tectonic setting of these and other ophiolites requires application of detailed geologic and petrologic data as well as geochemistry. The Ti/V discrimination diagram, however, is a potentially powerful adjunct to these techniques.

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Section: Partial Melting and Fractional Crystallizationmentioning

confidence: 99%

Section: Island Arc Lavasmentioning

confidence: 99%

Ti-V plots and the petrogenesis of modern and ophiolitic lavas

Shervais

1982

Earth and Planetary Science Letters

2,031

960

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“…Except for Ti, these jotunites are comparable to andesites and high-alumina basalts [61,62] : the Ni and Cr contents are low (<50 ppm and <30 ppm respectively), the Ni/Co ratio is lower than unity and the V/Ni ratio close to 10.…”

Section: Rogaland Datamentioning

confidence: 99%

Trace elements and anorthosite genesis

Duchesne

Demaiffe

1978

Earth and Planetary Science Letters

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Terrestrial massif anorthosites have gained new interest for the understanding of the deep zones of the crust and for the reconstitution of its history in Proterozoic time. The purpose of this paper is to show how trace elements can enlighten two controversial questions in the problem of anorthosites, namely the nature of the parental magma and the process which gives rise to related acidic rocks. Data obtained on rocks and minerals coming from the Rogaland anorthositic province, South Norway, are presented together with those available in the literature. The Sr and Ba in plagioclase and their relationship with Ca and K, K and Rb in rocks and plagioclases, rare earth elements (REE) in cumulate minerals and in various liquids, 87 Sr/ 86 Sr initial ratios on rocks and minerals as well as a few data on transition elements and on 18 O/ 16 O ratios are discussed in the different sections. Quantitative modelling of the behaviour of trace elements is realized mainly by graphical methods in the Bjerkrem-Sogndal layered lopolith and in the Hidra body, both andesine-type massifs. The major conclusions are as follows:(1) The parental magma of the andesine-type massifs has a jotunitic (hypersthene-monzodioritic) composition characterized by variable K/Rb ratios (from 480 to 1700), by the absence of an Eu anomaly, by variable REE contents (from 50 to 220 for La chondrite-normalized content) and by La/Yb ratios almost constant (from 6 to 12), as well as by high Ti and Fe contents, by transition elements indicating calc-alkaline affinities and by 87 Sr/ 86 Sr initial ratios similar to those of rocks derived from the upper mantle or the deep crust.(2) A jotunitic composition appears not to be compatible with the parental magma of the labradorite-type massif anorthosite. The relationship between andesine anorthosite and labradorite anorthosite cannot be described simply in terms of fractional crystallization.(3) Fractional crystallization can explain the succession of rocks from andesine anorthosite to leuconorite, to norite and finally to acidic rocks. In some cases however, namely the Bjerkrem-Sogndal lopolith in Rogaland, contamination by supracrustal material must be invoked and seems to have superimposed its effects on those of fractional crystallization.(4) Deformation, granulation and recrystallization do not appear to fractionate both the major and trace elements of the plagioclase, except Ti which is lowered.

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“…The abundances of some elements such as Cr, Ni, Sc, Co and Sr in the Hanasaki dolerites are similar to those in andesites, especially to those in high potash andesite, estimated by TAYLOR et al (1969). Fig.9 illustrates a similarity in the Cr and Ni contents of Hanasaki dolerites and andesites.…”

Section: And Discussionmentioning

confidence: 58%

“…Concerning the relation between Ni and Co in volcanic rocks, ISHIKAWA (1968) and ISHIKAWA and YAGI (1970) showed that almost all alkali basalts and basalts have a relation Ni>Co, whereas TAYLOR (1968) andTAYLOR et al (1969) showed the relation Ni<Co (Ni/Co=0.75) for andesites. The Hanasaki dolerites have a relation Ni<Co (Ni/Co=0.65).…”

Section: And Discussionmentioning

confidence: 99%