Kvarca smilšu uzkrāšanās apstākļi Baltijas Devona baseinā
2017
Stinkulis, G., University of Latvia, Riga (Latvia). Faculty of Geography and Earth Sciences
Quartz sand of the Middle Devonian Sietiņi Formation occurs in the north-eastern part of Latvia. Sand is fine- to coarse-grained; it contains gravel and pebble-size quartz grains and clay clasts. Subaqueous dunes and bars are dominant among the bedforms identified in the geological sections. Wide-scale sedimentological studies and palaeogeographic reconstructions by previous authors allow suggesting that the accumulation of the deposits took place in shallow epeiric basin (Куршс, 1992). Recent detailed studies (Pontén, Plink- Björklund, 2007) allow suggesting that the deposits have formed in delta plain environment. The content of quartz and other minerals resistant to weathering increases in these sandy deposits from west to east evidencing development of the chemical weathering crust in north-eastern parts of the source area.
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