By examining the minor and trace element contents of chromites from three intrusions—the Bushveld Complex (South Africa), Stillwater (USA), Great Dyke (Zimbabwe)—and comparing these chromite compositions with those magmas which they could have formed (komatiites picrites) we conclude that ( i) variations in Ti, V, Sc, Ga across stratigraphy individual layers do not support model magma mixing le...

No genetic link between the two main types of chromitite, stratiform and podiform chromitites, has ever been discussed. These chromitite have very different geological contexts; one is a member layered intrusions, representing fossil magma chambers, in crust, forms pod-like bodies, conduits, upper mantle. Chromite grains contain peculiar polymineralic inclusions derived from Na-bearing hydrous ...

cobalt chromite (cocr2o4) with normal spinel structure, shows catalytic activity for oxidation of unburned methane in the natural gas vehilcles (ngv). in this study, cocr2o4 nanoparticles were synthesized through a conventional co-precipitation technique and investigated for the catalytic combustion of methane. cobalt nitrate hexahydrate, chromium nitrate nonahydrate and ammonia solution (25%) ...

We examined oxygen three-isotope ratios of 48 extraterrestrial chromite (EC) grains extracted from mid-Ordovician sediments from two different locations in Sweden, and one location in south-central China. The ages of the sediments ( 470 Ma) coincide with the breakup event of the L chondrite parent asteroid. Elemental compositions of the chromite grains are generally consistent with their origin...

Gravity data inversion is one of the important steps in the interpretation of practical gravity data. The inversion result can be obtained by minimization of the Tikhonov objective function. The determination of an optimal regularization parameter is highly important in the gravity data inversion. In this work, an attempt was made to use the active constrain balancing (ACB) method to select the...

electron-probe microanalyses and scanning electron microscopy of chrornitites from some ultramafic members of neyriz ophiolite indicate that sulifides of platinum- group minerals (pgms) occur as solid inclusions in chromite grains. laurite with the general formula of (ru ,os ,lr ) s , and erlichmanite are the main identified sulfide phases. the pgms occur as 4 to 20 microns euhedral to rectangu...