文章基本信息

标题：Structural analysis of a subduction-related contact in southern Sesia-Lanzo Zone (Austroalpine Domain, Italian Western Alps)
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作者：Michela Cantù ; Luca Spaggiari ; Michele Zucali 等
期刊名称：Journal of Maps
印刷版ISSN：1744-5647
出版年度：2016
卷号：12
期号：sup1
页码：22-35
DOI：10.1080/17445647.2016.1155925
出版社：Journal of Maps
摘要：A new foliation trajectory map at 1:10000 scale, represented here with an interpretative structural map, is derived from an original field analysis at 1:5000 scale in the southern Sesia-Lanzo Zone (SLZ). It shows the relative chronology of overprinting foliations, characterised by the mineral assemblages that mark superposed fabrics in each rock type. This map and the associated cross-sections, which synthesise the 3D structural outline of the tectonic contact between the Eclogitic Micaschists Complex (EMC), the Rocca Canavese Thrust Sheets and the Lanzo Ultramafic Complex, allow the correlation of the structural and metamorphic imprints that developed in these crustal and mantle complexes during Alpine subduction. Furthermore, the map and cross-sections allow the immediate perception of the metamorphic environments in which the structural imprints developed in each complex successively under eclogite, blueschist and greenschist facies conditions. The represented structural and metamorphic evolution of the southern end of the SLZ (internal Western Alps) has been inferred based on multiscale structural analysis. The dominant fabrics at the regional scale are two superposed mylonitic foliations that developed under blueschist and greenschist facies conditions, respectively. Metamorphic assemblages underlying the successive fabrics in the different metamorphic complexes allow us to identify contrasting metamorphic evolutions indicating that the tectonic contacts between the EMC, the Rocca Canavese Thrust Sheets and the Lanzo Ultramafic Complex developed under blueschist facies conditions and were successively reactivated during the greenschist facies retrogression.
关键词：Foliation trajectory maps; multi-scale structural analysis; blueschist/eclogite facies rocks; Eclogitic Micaschists Complex; Rocca Canavese Thrust Sheets; Lanzo Massif