Abstract

A fundamental tectonic boundary between the Precambrian East European Craton (EEC) and the younger Phanerozoic mountain belts of Europe runs through Poland. Whereas the transition zone between both tectonical units was intensely investigated by means of electromagnetic methods in the past, the image of electric conductivity of the EEC itself has not been detailed so far. In the present study the lithospheric structure beneath the northeast of Poland is investigated by means of three parallel magnetotelluric profiles. As a result the Polish part of the craton does not appear as homogeneously highresistive as repeatedly reported. Beneath a shallow (from 2 to 4 km) sedimentary layer a less resistive structure (several hundred Ωm) under all three profiles in mid-crustal to upper mantle depth becomes apparent in the high-resistive background. It spatially coincides with a magmatic body of the Upper Proterozoic age called Śniardwy lake gabbro intrusion.

中文翻译：

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大地电磁调查的结果是东欧克拉通波兰部分下方的深层岩石圈结构

摘要

前寒武纪东欧克拉通（EEC）和欧洲较年轻的生代山带之间的基本构造边界贯穿波兰。过去，通过电磁方法对两个构造单元之间的过渡带进行了深入研究，但到目前为止，EEC本身的电导率图像尚未详述。在本研究中，通过三个平行的大地电磁剖面研究了波兰东北部以下的岩石圈结构。结果，克拉通的波兰部分看上去不像重复报道的那么均匀。在高电阻背景下，在中地壳至上地幔深度的所有三个剖面下的浅层沉积层（2至4 km）下，电阻率较低的结构（几百个Ωm）变得明显。