Chemical composition of rocks and minerals from the Weddell Sea

This work is devoted to results of the joint Russian-German geodynamic research carried out in the Weddell Sea and West Antarctica during cruise ANT-XXII/3 of R/V Polarstem in 2005. The study of rock samples collected from the sea floor showed that a heterogeneous structure of the Weddell Sea was formed by spatiotemporal combination of destruction of the continental crust, progressive thalassogenesis (oceanization-taphrogenesis), and rifting, as opposed to spreading origin. High post-consolidation mobility during the destruction stage led to areal dismembering and high permeability of the continental crust, as well as to tectonomagmatic activation. The main mechanism of re-working of the continental crust is recognized to be magmatic replacement by basic-ultrabasic mantle material with formation of the secondary oceanic crust and preservation of relics of the continental crust. The Earth's endogenous activity was driven by transmagmatic fluid flows, which ascended from the melted core and caused transformation of the Earth's crust and mantle.

本研究围绕2005年搭载极星号（R/V Polarstem）科考船执行ANT-XXII/3航次期间，于威德尔海（Weddell Sea）及西南极地区开展的俄德联合地球动力学研究成果展开。对海底采集的岩石样品分析显示，威德尔海的非均质构造并非源于扩张作用，而是大陆地壳破坏、渐进式洋化作用（thalassogenesis，即洋化-地堑作用）与裂谷作用的时空耦合结果。地壳破坏阶段的高固结后活动性，使得大陆地壳发生区域解体并具备高渗透性，同时引发构造-岩浆活化作用。学界普遍认为，大陆地壳再造的核心机制为：基性-超基性幔源物质开展岩浆交代作用，形成次生洋壳并留存大陆地壳的残余体。地球内生活动由源自熔融地核的穿岩浆流体（transmagmatic fluid）流动所驱动，此类流体上升并引发地壳与地幔的改造过程。