Abstract

The original results of a study of the composition of terrigenous rocks of the Early Silurian Kordonka Formation of the Paleozoic–Early Mesozoic Laoeling–Grodekovo Terrane (southern Primorye) are considered. The aim of the study was to interpret the paleogeodynamic setting of the rocks of the formation and to determine the type and the composition of the parental rocks of the source areas on the basis of genetic interpretation of the composition of studied rocks. It was found that, according to mineralogical–geochemical parameters, the rocks of the formation are typical graywackes and petrogeneic (first cycle) rocks, which formed mostly due to mechanical erosion of rocks of the source areas. The rocks exhibit a low degree of maturity and a high rate of burial of clastic material and weak lithodynamic reworking of the parental rocks. The results of a comprehensive study of the rock composition have been interpreted using comparison with that of ancient rocks and present-day sediments accumulated in certain geodynamic settings. Our data indicate that the rocks of the Kordonka Formation accumulated in an oceanic island-arc sedimentary basin. The clastic material was sourced from the arc, which was composed of mafic and intermediate volcanic rocks and igneous and sedimentary rocks of its basement.

中文翻译：

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滨海边疆区劳林-格罗德科沃地带的志留系下层陆源岩：组成和形成背景

摘要

考虑了对古生代-早中生代劳林-格罗德科沃地形（南部滨海边疆区）的志留纪早期Kordonka组陆相岩石组成的研究的原始结果。该研究的目的是在对被研究岩石组成进行遗传解释的基础上，解释地层岩石的古地球动力学背景，并确定源区母岩的类型和组成。根据矿物-地球化学参数，发现该地层的岩石是典型的灰泥岩和成岩（第一周期）岩石，这主要是由于源区岩石的机械侵蚀而形成的。这些岩石表现出较低的成熟度和高的碎屑物质埋藏率，并且对母体岩石的岩石动力学改造较弱。通过与古代岩石和在某些地球动力学环境中积累的当今沉积物的比较，解释了对岩石成分的全面研究结果。我们的数据表明，Kordonka组的岩石聚集在一个海洋岛弧沉积盆地中。碎屑物质来源于弧形，弧形由镁铁质和中层火山岩以及其基底的火成岩和沉积岩组成。