Geochemistry of Carbonaceous-Carbonate Metasomatites from a Deep Fault Zone

摘要

In the Kokchetav Block (northern Kazakhstan), geo-physicists have identified the Eastern Fault Zone, extending in the crust and below the Moho discontinuity for more than 100 km. Its fragments are traced in the Precambrian metamorphic rocks and the Paleozoic granitoids of the eastern Kokchetav Block. Although the fault zone is mostly overlapped by loose sediments, it was studied in the course of geological mapping in mine workings and quarries. The rock association of this zone indicates a long-lived nature. The zone is composed of high-pressure eclogites and amphibolite-facies metamorphic rocks (garnet-biotite, garnet-biotite-sillimanite, staurolite-garnet-biotite, and andalusite-garnet-biotite gneisses).