In this article, the most recent moldavite discoveries in Poland and their host sediments are characterised and discussed. They were discovered at Lasów, located about 8 km north of Zgorzelec (Poland) and Görlitz (Germany), about 700 m from the Polish-German border, close to the Lusatian Neisse (Nysa) River. The tektites were collected from Vistulian (Wiechselian) glacial age sand and gravel of a closed quarry pit, associated with the river terraces. In the Lasów area, the moldavite-bearing sediments are Pleistocene in age and represent Lusatian Neisse terrace deposits. They were redeposited from the upper part of the drainage basin of the Lusatian Neisse, probably washed out from the Miocene sediments that filled the Zittau Depression, the Berzdorf–Radomierzyce Depression, the Višňová Depression and the tectonically uplifted Izera Mts. and Działoszyn Depression. The erosion of Miocene deposit occured on a large scale in the uplifted foothills of the Upper Miocene Izera, Lusatia and Kaczawa complexes. The sediment cover was removed from the Działoszyn Depression. The drainage basin of the Lusatian Neisse is the area where moldavites were formed by the Nördlinger Ries impact. The source area of moldavite is the same for the Miocene deposits around Gozdnica, as well as for the Pleistocene sediments at Lasów.
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The Minjiang River terrace along the Longmen Shan fault zone near Wenchuan, at the eastern margin of the Tibetan Plateau, China, provides archives for tectonic activity and quaternary climate change. However, previous studies were not able to provide ages older than 100 ka due to the limitations of dating material or/and methods applied to date the fluvial sediments. In this study, we used the ESR signal of the Ti-Li center in quartz to obtain the ages of four higher terraces (T3-T6). According to the results, the terraces T3 to T6 were formed at 64±19 ka, 101±15 ka, 153±33 ka, and 423±115 ka, respectively. Combined with previous studies, these results indicate that the formations of all terraces correspond to glacial/interglacial transition periods, such as, T1-T5 being correlated to MIS2/1, MIS4/3, MIS5d/5c, and MIS6/5e respectively, while T6 probably to MIS12/11. According to these data, it is found that the average incision rate was significantly higher over the last 150 ka than that previous 100 ka (250 to 150 ka). As both tectonics and climate have affected the formation of these terraces, in addition to the overall uplifting of Tibetan Plateau, the regional uplift due to isostasy would be an additional tectonic factor in the formation of river terraces in the eastern margin of Ti-betan plateau.
Złoża kruszywa naturalnego w dolinie Soły położone są w obrębie czwartorzędowej terasy rędzinnej i eksploatowane systemem basenowym spod wody. Na miejscu terenów rolniczych, cechujących się z reguły wysoką bonitacją gleb, powstają duże wyrobiska zawodnione, które zmieniają naturalny krajobraz doliny tej rzeki i wykluczają uprawy rolne. Pod pozorem troski o zagospodarowanie pogórnicze użytkownicy złóż deklarują ogólnikowo budowę zbiorników wodnych, których funkcja nie jest wystarczająco sprecyzowana. Daje to szerokie pole do dowolnych interpretacji i skutkuje pozostawieniem mało użytecznych akwenów wśród zdegradowanego terenu. Przeprowadzono analizę warunków przyrodniczych: geologicznych, hydrogeologicznych, glebowych i stanu przyrody żywej, na podstawie której urealniono możliwości wykorzystania terenów po eksploatacji kruszywa naturalnego i przedstawiono propozycje nadania im nowej funkcji stosownie do warunków przeobrażonego środowiska
EN
Deposits of the natural aggregates along the Soła valley were formed within Quaternary rendzina terrace. They are exploited from under the groundwater level. As a result, many hectares of valuable agricultural land are converted into post-mining pits, which change the natural environment of the Soła valley and preclude future crops. Being forced to declare post-mining redevelopment mode, users of the natural aggregate deposits declared construction of water reservoirs, which they call fishing ponds. However, in reality the ponds are used for recreation fishing but not for productive fish farming, which appears impossible, which cannot be drained in deep basins. A panorama of possible ways of reclamation of post-mining pits based on natural environment and social conditions is discussed, forming main body of the paper
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