An Alternative Scenario on the Origin of Ultra-High\u00a0<\/b>Pressure (UHP) and Super-Reduced (SuR) Minerals in\u00a0<\/b>Ophiolitic Chromitites: A Case Study from the\u00a0<\/b>Mercedita Deposit (Eastern Cuba)<\/b><\/p>\n
Abstract<\/u><\/p>\n
The origin of the assemblage of ultra-high pressure (UHP), super-reduced (SuR) and\u00a0several crustally derived phases in ophiolitic chromitites is still hotly debated. In this paper, we\u00a0report, for the first time, this assemblage of phases in ophiolitic chromitites of the Caribbean. We studied the Mercedita chromitite deposit in the eastern Cuban ophiolitic complexes. The mineral\u00a0phases were characterized using microRaman spectroscopy, energy-dispersive spectroscopy with a\u00a0scanning electron microscope (SEM-EDS), X-ray microdiffraction and electron microprobe analyses.\u00a0Mineral concentrates were prepared using hydroseparation techniques. We have identified oriented\u00a0clinopyroxene lamellae in chromite, oriented rutile lamellae in chromite, moissanite hosted in the\u00a0altered matrix of the chromitite, graphite-like amorphous carbon, corundum and SiO2 hosted in\u00a0healed fractures in chromite grains, and native Cu and Fe\u2013Mn alloy recovered in heavy-mineral\u00a0concentrates obtained by hydroseparation. This assemblage may correspond to UHP-SuR conditions,\u00a0implying recycling of chromitite in the mantle or formation of the chromite grains at deep mantle\u00a0depths, followed by emplacement at a shallow level in the mantle. However, the chromitite bodies\u00a0contain gabbro sills oriented parallel to the elongation of the chromitite lenses, and these show\u00a0no evidence of HP\/UHP metamorphism. Therefore, the identified \u201cexotic\u201d phases may not be\u00a0indicative of UHP. They formed independently as oriented clinopyroxene lamellae in chromite during\u00a0cooling (clinopyroxene and rutile), in super-reduced microenvironments during the serpentinization\u00a0processes, and by transference of subducted crustal material to the mantle wedge via cold plumes.<\/p>\n
Keywords:<\/strong> moissanite; inclusions; Mercedita; serpentinization; super-reducing conditions;\u00a0chromitites; ophiolites; Cuba<\/p>\n ----------------------------------------------------------------------------------------------------------<\/p>\n To Cite this article:<\/strong> Pujol-Sol\u00e0, N.; Proenza, J.A.; Garcia-Casco, A.; Gonz\u00e1lez-Jim\u00e9nez, J.M.; Andreazini, A.; Melgarejo, J.C.; Gervilla, F. An Alternative Scenario on the Origin of Ultra-High Pressure (UHP) and Super-Reduced (SuR) Minerals in Ophiolitic Chromitites: A Case Study from the Mercedita Deposit (Eastern Cuba).\u00a0Minerals<\/em>\u00a02018<\/b>,\u00a08<\/em>, 433.<\/p>\n DOI<\/strong>: 10.3390\/min8100433<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"An Alternative Scenario on the Origin of Ultra-High\u00a0Pressure (UHP) and Super-Reduced (SuR) Minerals in\u00a0Ophiolitic Chromitites: A Case Study from the\u00a0Mercedita Deposit (Eastern Cuba) Abstract The origin of the assemblage of ultra-high pressure (UHP), super-reduced (SuR) and\u00a0several crustally derived phases in ophiolitic chromitites is still hotly debated. In this paper, we\u00a0report, for the first time, this assemblage of phases in ophiolitic Continue Reading<\/a>","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[128,40,44],"tags":[],"class_list":["post-3639","post","type-post","status-publish","format-standard","hentry","category-128","category-cuba","category-publications","cat-128-id","cat-40-id","cat-44-id"],"_links":{"self":[{"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=\/wp\/v2\/posts\/3639","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3639"}],"version-history":[{"count":2,"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=\/wp\/v2\/posts\/3639\/revisions"}],"predecessor-version":[{"id":3641,"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=\/wp\/v2\/posts\/3639\/revisions\/3641"}],"wp:attachment":[{"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3639"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3639"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/caribbeanlithos.ub.edu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3639"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}