G. R. Himmelberg F.E. Goff G.K. Czamanske 1976 <div id="abstracts" class="Abstracts u-font-serif text-s"><div id="ab1" class="abstract author" lang="en"><div id="aep-abstract-sec-id7"><div id="abstracts" class="Abstracts u-font-serif text-s"><div id="ab1" class="abstract author" lang="en"><div id="aep-abstract-sec-id7"><p>Zoned spinel of unusual composition and morphology has been found in massive pyrrhotite-chalcopyrite-pent-landite ore from the La Perouse layered gabbro intrusion in the Fairweather Range, southeastern Alaska. The spinel grains show continuous zoning from cores with up to 53 wt.% Cr₂O₃&nbsp;to rims with less than 11 wt.% Cr₂O₃. Their composition is exceptional because they contain less than 0.32 wt.% MgO and less than 0.10 wt.% Al₂O₃&nbsp;and TiO₂. Also notable are the concentrations of MnO and V₂O₃, which reach 4.73 and 4.50 wt.%, respectively, in the cores. The spinel is thought to have crystallized at low oxygen fugacity and at temperatures above 900°C, directly from a sulfide melt that separated by immiscibility from the gabbroic parental magma.<br></p></div></div></div></div></div></div><ul id="issue-navigation" class="issue-navigation u-margin-s-bottom u-bg-grey1"></ul> application/pdf 10.1016/0012-821X(76)90163-1 en Elsevier Zoned Cr, Fe-spinel from the La Perouse layered gabbro, Fairweather Range, Alaska article