Correlation of the supracrustal complexes of the Small and Large Keivy, North-East of the Baltic Shield

The issue of correlation between the Small and Large Keivy sections is considered using a technique that includes searching for trends in partially ordered sets of random variables and assessing the degree of similarity/difference between rock compositions. The lower part of the section (Chervurt formations) of the Keivy structure was formed as a result of rewashing and redeposition of the substance of the structure itself. The formation of the Large Keivy section continued in the same regime with the formation of the Vykhchurt subsuites. With the activation of the tectonic regime, the Pestsovtundra suite, which completes the Large Keivy section, was formed due to the substance of the underlying Chervurt complexes and framing rocks (primarily the rocks of the Murmansk block). The formation of the Small Keivy section at the same stage occurred in a different way. With the activation of the tectonic regime, less than that which accompanied the formation of the Pestsovtundra complexes of the Large Keivy, the deposition of the Snezhnoborsky complexes began. The Upper Chervurt formations participated to a significant extent in their formation, but the products of the destruction of the framing rocks (primarily the Murmansk domain) were a noticeable addition. At this point, the formation of the Keivy sections was completed. The described difference in the processes that accompanied the accumulation of sediments in the Large and Small Keivy sections is explained by the differences in the position of these areas within the paleobasin of the Keivy time.