The Quantometer, A Direct Reading Instrument for Spectrochemical Analysis

Hasler, M. F.; Lindhurst, R. W.; Kemp, Jeff

doi:10.1364/josa.38.000789

Cited by 31 publications

(5 citation statements)

References 3 publications

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“…Their low abundances in magnetite of carbonatitic origin reflect the scarcity of Cr, Ni and Co in carbonatitic magmas. To our knowledge, the only systematic study of Cr, Ni and Co distribution in magnetite from various carbonatitic rocks is that by Bagdasarov (1989), where these elements were quantified in "bulk" (0.4 g) monomineralic samples by quantometric analysis (Hasler et al 1948). According to Bagdasarov (1989), the highest Cr, Ni and Co contents are found in magnetite from the so-called "linear-fracture-type" carbonatites ( Table 1).…”

Section: Trace-element Budget Of Magnetite In Carbonatitesmentioning

confidence: 99%

Early Magmatic and Reaction-Induced Trends in Magnetite From the Carbonatites of Kerimasi, Tanzania

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Chakhmouradian

Halden

et al. 2008

The Canadian Mineralogist

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We examined the mode of occurrence, pattern of zoning and composition of magnetite and associated spinel-group minerals in three types of calciocarbonatite from the Kerimasi volcano, in Tanzania. In all samples, magnetite is one of the earliest phases to have crystallized, and shows an appreciable compositional variation. The majority of compositions correspond to magnetite with low to moderate proportions of magnesioferrite and ulvöspinel components (10-28 and 2-28 mol.%, respectively) and <15 mol.% of spinel and jacobsite. One sample of pyroclastic carbonatite also contains crystals of Mn-rich magnesioferrite (15-17 mol.% MnFe 2 O 4 ). The two trace elements consistently present in appreciable amounts are V (400-2000 ppm) and Zn (700-3300 ppm); the abundances of other trace elements are much lower and very variable (≤15 ppm Cr, 170 ppm Ni, 220 ppm Co, 490 ppm Zr, 14 ppm Hf, 95 ppm Nb, 3 ppm Ta, and 80 ppm Ga). Magnetite is thus a minor host of Zr, Hf, Nb and Ta in carbonatites. The composition of magnetite crystallizing from carbonatitic magma evolves by becoming depleted in Mg and Ti, whereas its Al content inversely correlates with the V content and, thus, is sensitive to variations in f(O 2 ). The compatibility of V is interpreted to decrease, and that of Mn to increase, with increasing f(O 2 ). Covariation between the Mn and Zn contents suggests that the partitioning behavior of Zn is controlled by the coupled substitution Zn 2+ Mn 3+ Fe 2+ -1 Fe 3+ -1 . The Mg-Ti depletion trend is accompanied by a decrease in Zr and Ta contents at constant or decreasing levels of Nb and Hf, which has implications for the partitioning behavior of high-field-strength elements in carbonate melts. In addition to the magmatic evolutionary trend, the Kerimasi magnetite exhibits a previously unrecognized trend arising from a reaction of the magnetite with the carbonatitic magma. This trend involves enrichment of the peripheral parts of magnetite crystals in Mg, Al, Mn, Zr and Nb, and their mantling by Fe-rich spinel. This trend requires that a(Mg 2+ ) and a(Al 3+ ) in the magma increase with evolution, whereas a(SiO 2 ) remains low to impede the precipitation of Mg-Al silicates.

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Section: Trace-element Budget Of Magnetite In Carbonatitesmentioning

confidence: 99%

Early Magmatic and Reaction-Induced Trends in Magnetite From the Carbonatites of Kerimasi, Tanzania

Reguir

Chakhmouradian

Halden

et al. 2008

The Canadian Mineralogist

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show abstract

“…Recent developments on the Quantometer have been described by several authors (11,78,218,220,286). Features include improved thermal and mechanical stability and an automatic circuit to compensate for zero drifts always present in direct current amplifiers.…”

Section: Measurementmentioning

confidence: 99%

Automatic Operations in Analytical Chemistry

Patterson¹,

Mellon²

1951

Anal. Chem.

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“…The epitome in recent development in instrumentation has perhaps been reached in the Quantometer and other automatic recording emission spectrographs such as those developed by Saunderson (38), Nahstoll (31), and Hasler (21). This type of apparatus is the analytical instrument demanded by all-an instrument into which the sample is fed, and from or on which the results immediately appear.…”

Section: Controllingmentioning

confidence: 99%

Current Trends in Analytical Chemistry

Elving¹

1950

Anal. Chem.

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The Quantometer, A Direct Reading Instrument for Spectrochemical Analysis

Cited by 31 publications

References 3 publications

Early Magmatic and Reaction-Induced Trends in Magnetite From the Carbonatites of Kerimasi, Tanzania

Early Magmatic and Reaction-Induced Trends in Magnetite From the Carbonatites of Kerimasi, Tanzania

Automatic Operations in Analytical Chemistry

Current Trends in Analytical Chemistry

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