Surowce illaste ceramiki budowlanej woj. łódzkim .

Abstract

CLAY MINERAL RAW MATERIALS FOR BUILDING CERAMICS IN THE ŁÓDŹ VOIVODSHIP Summary Genetically, the occurrence of clay .raw materials used :for production at building ceramics is related, in the Łódź voivodship, to their geological age. Predominant are here Quaternary deposits among which boulder clays are the main mineral raw material used in most of the ceramic factories of :the area considered. Only small percentage of this group is represented by Quaternary silts and clays. Both documented and registered reserves of the Quaternary deposits amount to 75,6%, of the total reserves of the voivodship discussed. The group of the Tertiary deposits is represented by Pliocene clays of inland origin. The evidenced reserves of these deposits make a small percentage only and amount to 7,9'% of the total reserves of the Łódź voivodship. The second group. as concerns the quantity of reserves (16,5%) is made by the deposits of the older geological formations. The occurrence of these formations is related to the southern part of the area in study (region of Wieluń). For building ceramics are used here also Middle Jurassic clays of Dagger age.