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Współczesne obszary występowania mołdawitów : wnioski z eksperymentu transportowania ich przez Nysę Łużycką

100%

Brachaniec T.

Przegląd Geologiczny

2022

tom Vol. 70, nr 1

61--65

Tektites in the sedimentary recordare subject to many geological processes such as fluvial reworking. To observe the glass behaviour during reworking, an experiment was conducted in the Lusatia Neisse river where moldavites are found. It consisted in observing the progressive abrasion of some 500 tektites over reworking distances of 100, 200, 300, and 400 km respectively. The results clearly show that moldavites could survive reworkingover a distance of several hundreds km. The decrease in weight was linear in relation to the distance travelled. Regardless of the initial shape, all tektites became rounded with a smooth surface after travelling 200 km. The experimental results suggest that European tektites were ejected from the Ries crater over distances reaching up to 600 km and were then reworked over short distances from the origin areas of the current substrewn fields.

Polskie mołdawity : obecny stan wiedzy i perspektywy nowych znalezisk

51%

Szopa K. , Brachaniec T. , Karwowski Ł.

tom Vol. 67, nr 8

662--667

The first Polish moldavites were discovered in 2012. This paper is a summary of the distribution and inventory of these Polish tektites. Up to the present, 28 moldavites have been described from seven different sandpits. These moldavites were deposited in the upper Miocene fluvial deposits of the Gozdnica Formation, as well as in the Pleistocene river terraces. Apart from a typical bottle green colour, moldavites also have other diagnostics features for this class of tektites, such as the presence of bubbles, inclusions oflechatelierite, as well as the same, homogeneous chemical composition. Fluvial redeposition was interpreted as the main process which determined moldavite distribution. Despite the most recent find of one moldavite specimen in Bielawy, all of these specimens indicate both Lusatian as well as sub-strewn Czech fields as their supply area.