{"title":"FROM MAGMATIC TO METAMORPHIC DEFORMATIONS IN A JURASSIC OPHIOLITIC COMPLEX: THE BRACCO GABBROIC MASSIF, EASTERN LIGURIA (ITALY)","authors":"F. Menna","doi":"10.4454/OFIOLITI.V34I2.382","DOIUrl":null,"url":null,"abstract":"A new structural study with multiscale detailed analysis of the main elements of the fabric was performed on the Bracco ophiolitic massif (Eastern Liguria). The results are here presented with a reconstruction of the sequence of events which characterized the evolution of the gabbroic complex, starting form the first magmatic phases up to the late metamorphic ones, through a retrograde path which ended with the final exposure of the gabbro on the ocean floor. The field observations, supported by petrographic analyses, lead to outline for the Bracco Gabbroic Complex a deformative evolution which started in the early magmatic phases; the study of the metamorphic structures, following the intrusion and the syn-magmatic deformation of the gabbroic complex, allowed to identify three distinct metamorphic phases, whose petrographic features show that the associated deformations could actually represent a continuous evolution of the same tectonic phenomenon, which started under granulitic facies conditions, continued in amphibolitic facies and ended with deformations and recrystallizations in greenschist facies conditions.","PeriodicalId":54690,"journal":{"name":"Ofioliti","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2009-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"13","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ofioliti","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.4454/OFIOLITI.V34I2.382","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOLOGY","Score":null,"Total":0}
引用次数: 13
Abstract
A new structural study with multiscale detailed analysis of the main elements of the fabric was performed on the Bracco ophiolitic massif (Eastern Liguria). The results are here presented with a reconstruction of the sequence of events which characterized the evolution of the gabbroic complex, starting form the first magmatic phases up to the late metamorphic ones, through a retrograde path which ended with the final exposure of the gabbro on the ocean floor. The field observations, supported by petrographic analyses, lead to outline for the Bracco Gabbroic Complex a deformative evolution which started in the early magmatic phases; the study of the metamorphic structures, following the intrusion and the syn-magmatic deformation of the gabbroic complex, allowed to identify three distinct metamorphic phases, whose petrographic features show that the associated deformations could actually represent a continuous evolution of the same tectonic phenomenon, which started under granulitic facies conditions, continued in amphibolitic facies and ended with deformations and recrystallizations in greenschist facies conditions.
期刊介绍:
Since 1976, Ofioliti provides an international forum for original contributions and reviews in the field of the geodynamics, petrology, geochemistry, biostratigraphy, stratigraphy, tectonics and paleogeography applied to ophiolitic terrains and modern oceanic lithosphere, including their sedimentary cover. Studies of topics such as geodynamics of the mantle, the evolution of orogens including ophiolites and paleoceanography are also welcome