Composition of rocks and minerals from the Bol'shoy Lyakhovsky Island (New Siberian Islands) ...

• Main Authors: Kuzmichev, A B, Sklyarov, E V, Barash, I G
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2005
• Subjects: Archive of Ocean Data ARCOD; New Siberian Islands
• Online Access: https://dx.doi.org/10.1594/pangaea.782548; https://doi.pangaea.de/10.1594/PANGAEA.782548

In the southeast of the Bolshoi Lyakhovsky Island there are outcrops of tectonic outliers composed of low-K medium-Ti tholeiitic basic rocks represented by low altered pillow basalts, as well as by their metamorphosed analogs: amphibolites and blueschists. The rocks are depleted in light rare-earth elements and were melted out of a depleted mantle source enriched in Th, Nb, and Zr also contributed to the rock formation. The magma sources were not affected by subduction-related fluids or melts. The rocks were part of the Jurassic South Anyui ocean basin crust. The blueschists are the crust of the same basin submerged beneath the more southern Anyui-Svyatoi Nos arc to depth of 30-40 km. Pressure and temperature of metamorphism suggest a setting of "warm" subduction. Mineral assemblages of the blueschists record time of a collision of the Anyui-Svyatoi Nos island arc and the New Siberian continental block expressed as a counter-clockwise PT trend. The pressure jump during the collision corresponds to heaping of ... : Supplement to: Kuzmichev, A B; Sklyarov, E V; Barash, I G (2005): Pillow basalts and blueschists on Bolshoi Lyakhovsky Island (New Siberian Islands) - fragments of the South Anyui ocean lithosphere. Geologiya i Geofizika (Geology and Geophysics), 46(12), 1367-1381 ...