The Range of Spinel Compositions in Terrestrial Mafic and Ultramafic Rocks

  title={The Range of Spinel Compositions in Terrestrial Mafic and Ultramafic Rocks},
  author={Steve Barnes and Peter L Roeder},
  journal={Journal of Petrology},
Compositional fields for spinels from a wide variety of mafic– a wide range of conditions from mafic and ultramafic ultramafic igneous rock types and tectonic environments have been magmas and, in the case of chromites, are often among determined from a global database of over 26 000 analyses. the first phases to crystallize. They also exhibit a wide These fields are defined using contoured data density plots based range of solid solution, the thermodynamics of which has on the spinel prism… 
Chemical Composition of Spinel‐group Minerals from the Paleozoic Asian Ophiolite Mélanges and Its Petrogenetic Significance
Historically, ophiolitic chromitites have satisfied more than half of the world’s ore production needs despite of their small scale compared to those layerd intrusions (Stowe, 1987). Spinels are
Spinel, olivine, and pyroxene chemistry of the Eoarchaean Manfred Complex (Yilgarn Craton, Western Australia), with implications for the tectonic setting of Archaean layered mafic intrusions and the stabilisation of continental nuclei
Abstract Anorthosite complexes are distinctive components of Archaean cratons and their petrogenesis has implications for ancient mantle evolution, early Earth geodynamics, and growth of continental
Chromium spinel in Late Quaternary volcanic rocks from Kamchatka: Implications for spatial compositional variability of subarc mantle and its oxidation state
The Kamchatka volcanic arc (Russia) is one of well-studied but complex tectonic margins on Earth, with an extensive geologic history stretching as far back as the Late Cretaceous. Unlike many other
Cr-spinel compositions, metadunite petrology, and the petrotectonic history of Blue Ridge ophiolites, Southern Appalachian Orogen, USA
Abstract Resolution of the petrotectonic history of Blue Ridge ophiolites of the Southern Appalachian Orogen has remained enigmatic because of metamorphism and tectonic fragmentation of ultramafic
Petrogenesis of ultramafic and mafic xenoliths from Mesozoic basanites in southern Sweden: constraints from mineral chemistry
Jurassic basanite necks occurring at the junction of two major fault zones in Scania contain ultramafic (peridotites, pyroxenites) and mafic xenoliths, which together indicate a diversity of upper
Geochemistry and tectonic setting of mafic rocks from the Othris Ophiolite, Greece
We present new geochemical analyses of minerals and whole rocks for a suite of mafic rocks from the crustal section of the Othris Ophiolite in central Greece. The mafic rocks form three chemically
On the relative timing of listwaenite formation and chromian spinel equilibration in serpentinites
Abstract Ultramafic rocks exposed at the Earth’s surface generally record multiple stages of evolution that may include melt extraction, serpentinization, carbonatization, and metamorphism. When
Mafic and ultramafic rocks, and platinum mineralisation potential, in the Longwood Range, Southland, New Zealand
Abstract Intrusive rocks in the Longwood Range represent a component of the Permian Brook Street Terrane. They include diffusely layered, cumulate-textured olivine gabbro, troctolite, and gabbro, and
Lithogeochemistry and spinel compositions in the ultramafic complexes of Western Ethiopia : criteria for the identification of Alaskan-type intrusions
This thesis covers two separate but complimentary themes. Firstly, work on the spinel composition of the ultramafic rocks of has provided evidence that they formed as Alaskan-type intrusions. This
Subduction of mantle wedge peridotites: Evidence from the Higashi‐akaishi ultramafic body in the Sanbagawa metamorphic belt
The Higashi-akaishi garnet-bearing ultramafic body in the Sanbagawa metamorphic belt, Southwest Japan, represents a rare example of oceanic-type ultrahigh-pressure metamorphism. The body of 2 km × 5


Chromite; from the fiery rain of chondrules to the Kilauea Iki lava lake
Chromite, spinel and magnetite compositions from a wide range of geological environments have been accumulated from published and unpublished sources in order to better characterize the spinel-group
Factors Controlling Chemistry of Magmatic Spinel: an Empirical Study of Associated Olivine, Cr-spinel and Melt Inclusions from Primitive Rocks
Compositions of ~2500 spinel-olivine pairs and 400 melt inclusion-spinel pairs have been analysed from 36 igneous suites from oceanic, arc and intraplate tectonic settings. Our data confirm that
Spinels and Mg Ilmenites from the Noril’sk 1 and Talnakh Intrusions and Other Mafic Rocks of the Siberian Flood Basalt Province
Spinels from the mineralized Noril’sk 1 and Talnakh intrusions show a broad and distinctive compositional spectrum, from normal chromite to Ti-enriched aluminous magnetite. In the Talnakh intrusion,
Microphenocrysts of chromian spinel in glass from an East Pacific Rise lava and three Icelandic subglacial lavas show a variety of complex skeletal, hopper, vermiform and chain textures. These grains
Chromite in Komatiites, 1. Magmatic Controls on Crystallization and Composition
Chromite is a widespread accessory mineral in komatiites, ranging Zhou & Kerrich, 1992). This is the first in a series of papers which addresses the occurrence of chromite in from skeletal through
Petrology and Geochemistry of Boninites from the North Termination of the Tonga Trench: Constraints on the Generation Conditions of Primary High-Ca Boninite Magmas
We report here a detailed mineralogical, geochemical, and experimental study of a high-Ca boninite suite from the northern termination of the Tonga trench. Most samples are strongly olivine
Chromite in Komatiites, II. Modification during Greenschist to Mid-Amphibolite Facies Metamorphism
Chromite compositions in komatiites are influenced by metamorphic chromite is highly susceptible to modification during processes, particularly above 500°C. Metamorphosed chromite is early hydrous
Chrome–spinels in gabbro–wehrlite intrusions of the Pechenga area, Kola Peninsula, Russia: emphasis on alteration features
Abstract Chrome–spinels are common accessory minerals of the Pechenga ultramafic rocks in NW Russia, varying in metamorphic grade from sub-greenschist to amphibolite facies. Magmatic chrome–spinels
Geochemical characteristics of aluminum depleted and undepleted komatiites and HREE-enriched low-Ti tholeiites, western Abitibi greenstone belt: A heterogeneous mantle plume-convergent margin environment
A compositionally diverse suite of komatiites, komatiitic basalts, and basalts coexist in the Tisdale volcanic assemblage of the late-Archean (∼2.7 Ga) Abitibi greenstone belt. The komatiites are
Chemistry of chromian spinel in volcanic rocks as a potential guide to magma chemistry.
Chromian spinel in volcanic rocks is a potential discriminant for magma chemistry. The TiO2 content of spinel, compared at similar Fe3+/(Cr + A1 + Fe 3+) ratios, can distinguish island arc basalts