O niektórych przejawach diagenezy tzw. dolego wapienia węglowego Gór Bardzkich.
Abstract
Some aspects of the diagenesis of the so-called Lower Carboniferous Limestone of the Bardzkie Mts
Abstract
The so-called Lower Carboniferous Limestone of the Bardzkie Mts. has been ascertained as allochemical sparitic limestones (biosparrudite, biosparite. intrasparrudite, intrasparite, and pelsparite). These rocks contain abounding litho-clastic elements: scraps of the Sowie Mts. gneisses, polycrystalline quartz grains, feldspars, and flaky minerals. The lithoclastic components display numerous features of weathering (particularly feldspars and flaky minerals) and crushing: microcracking, disintegration of relatively big grains into a fine mosaic composed of sharp-edged fragments cemented with iron oxides and submicroscopic mineral mush. The calcareous rocks have been affected by moderate diagenesis. Among diagenetic processes, the most intensely imprinted were recrystallization, micritization, and early-diagenetic dolomitization. As a result of recrystallization the rocks have become sparenitic in appearance, although their primary matrix is assumed to consist of micritic mud. An enormous abundance of authigenic quartz in the matrix of one of intrasparrudite beds (in places up to 80 vol. % of the matrix) has been regarded as evidence of volcanic activity in the area adjacent to the Bardo Basin at the end of the early Visean.
The carbonate rocks in question have originated as a result of rapid redeposition of the slightly or unconsolidated materials previously accumulated in a shallow-water environment (ooids, protooncolitcs. rich and various shallow-water fauna).