Major elements and REE in tektites and three probable shock-metamorphic rock series of the Baltic shield.

Abstract

REE contents of four tektites from separate strewn-fields have been determined and the REE and major elements in ten shock-metamorphic rocks from lakes Lappajarvi, Saaksjarvi (Finland), and Janisjarvi (Soviet Karelia). Neither the impact of meteorite or comet nor secondary weathering seems to change the REE content or distribution pattern in rocks. Therefore, where the texture and major element composition in country rock has changed through impact and after it, REE can be used as indicators of the original rock or sediment type. The surfaces of the Moon and each planet, including the earth, probably have unique REE distribution patterns as a result of the prevailing endogenic and exogenic processes. The distribution patterns of REE in tektites, are quite similar to those found in sediments, sedimentary rocks and shock-melted rocks. Accordingly, the origin of tektites from silica-rich clayey sediments or silicic rocks through impact is strongly indicated.