Nowy punkt występowania tufitów dolnodewońskich w Górach Świętokrzyskich
Abstract
NEW SITE OF LOWER DEVONIAN TUFFITES IN THE ŚWIĘTOKRZYSKIE MTS.
Summary
The paper presents the characteristics of geological conditions and the preliminary petrographical description of the first Lower Devonian tuffite occurrence sites in the southern area of the Świętokrzyskie Mountains. The tuffites have been found to occur in area penetrated by an inclined bore hole Wszachów-2, at a depth of 19.3 - 19.8 m, where they rest at the lower part of the classic series of Emsian age (Fig. 2). The contact of the tuffites with the adjacent formations of Emsian age is concordant, but not too distinct (Figs. 2 and 3). Macroscopically, the tuffites can be divided into two varieties: contact tuffite, green in colour, and psammite tuffite, sea-green in colour, which dominates in the section (Fig. 1). Microscopic examinations have demonstrated that about 75% of tuffite consist of an altered clay mass, and the remaining 25% is built up of various clastic material: quartz, feldspars, kaolinite pseudomorphs, quartzite fragments, dark rock porphyraceous fragments, relicts of glass. Mineral composition of the cementing mass at clayey character has preliminarily been established as a mixture of seladonite and kaolinite (Fig. 4). The Lower Devonian tuffites, so far known to occur in the vicinity of Barcza, rest within palaeonotologically dated deposits of Upper Emsian age. As a result of the examinations the tuffites from bore hole Wszachów-2 may be regarded as an equivalent of the Upper Emsian tuffite from Barcza. Acceptingthis opinion, we may refer the faunistically barren clastic deposits of Lower Devonian age from the southern region of the Świętokrzyskie Mts. to the Upper Emsian.
Summary
The paper presents the characteristics of geological conditions and the preliminary petrographical description of the first Lower Devonian tuffite occurrence sites in the southern area of the Świętokrzyskie Mountains. The tuffites have been found to occur in area penetrated by an inclined bore hole Wszachów-2, at a depth of 19.3 - 19.8 m, where they rest at the lower part of the classic series of Emsian age (Fig. 2). The contact of the tuffites with the adjacent formations of Emsian age is concordant, but not too distinct (Figs. 2 and 3). Macroscopically, the tuffites can be divided into two varieties: contact tuffite, green in colour, and psammite tuffite, sea-green in colour, which dominates in the section (Fig. 1). Microscopic examinations have demonstrated that about 75% of tuffite consist of an altered clay mass, and the remaining 25% is built up of various clastic material: quartz, feldspars, kaolinite pseudomorphs, quartzite fragments, dark rock porphyraceous fragments, relicts of glass. Mineral composition of the cementing mass at clayey character has preliminarily been established as a mixture of seladonite and kaolinite (Fig. 4). The Lower Devonian tuffites, so far known to occur in the vicinity of Barcza, rest within palaeonotologically dated deposits of Upper Emsian age. As a result of the examinations the tuffites from bore hole Wszachów-2 may be regarded as an equivalent of the Upper Emsian tuffite from Barcza. Acceptingthis opinion, we may refer the faunistically barren clastic deposits of Lower Devonian age from the southern region of the Świętokrzyskie Mts. to the Upper Emsian.