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EN
The paper presents results of bathymetric measurements performed on three crater lakes located in the “Meteoryt Morasko” reserve in west Poland. The maximum depth of the largest of the analysed lakes (1695 m2) was determined to amount to 2.6 m. The parameters of the lake (surface area, depth, etc.) are largely determined by a ditch dug through the crater in the north-western part of the lake, affecting the maximum water volume accumulated in the lake.
EN
There are specified criteria used to verify if some geological structure was developed during hypervelocity impact. Some of them are related to the passage of a shock wave through rocks, so are considered as definitive. Porządzie, Jaszczulty & Ochudno are structures discovered in 2014 (based on LiDAR data). They have many features suggesting possible impact origin. In shape of Porządzie there can be even recognized possible traces of shock waves, similar to those present during hypersonic flow (similar to observed e.g. in an airburst shape of extraordinary bright meteors). Unfortunately, this kind of observations (morphometry) on Earth is still considered as not enough to confirm the crater. The aim of recent study was to search for additional traces, which may help to prove that mentioned structures were created during common oblique impact event. Initially there were chosen 3 locations for outcrops, but finally samples were collected from 6 smaller pits. In Porzadzie structure there were discovered cemented rocks with various shape and size (concretions or lithic, parautochtonous breccias) and 2 rocks with possibly shocked quartz, having basal sets of thin and straight lamellae. On once surface there were recognized hierarchal branched (including spoon-like) structures resembling shatter cones. In uprange, at depth of about 50–70 cm, soil was rich in small charcoal pieces (like in other relatively small craters: e.g. Campo del Cielo, Whitecourt, Kaali, Ilumetsa, Morasko). All these observations, taken together with previous results, are about to confirm impact origin of Porzadzie crater.
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EN
Lonar crater in India, centered at 19.97°N and 76.50°E is relatively young (few tens of thousands years) and, thus, well preserved meteorite impact structure. This 1.88-km-diameter simple structure has been formed into the 66 Ma old Deccan traps. As the target of Lonar is magnetically homogeneous, it is a perfect site to study the effect of relatively small impact event into the magnetic properties of rocks, and the magnetic field. In October 2017, has been performed ground magnetic mapping of Lonar with help of two proton precession magnetometers. The mapping was done in a squared area of about 36 km2 (6´6 km) including the crater depression, rims, and surrounding terrain. Magnetic map (not corrected for latitude) reveals a circular negative anomaly more than 1000 nT in amplitude, which corresponds to the crater depression. The negative anomaly is surrounded by semicircular feature of up to 500 nT positive anomalies that correlate with present rim of the crater. The total diameter of the Lonar magnetic anomalies is about 2.25 km, which is just 20% more compared to the crater rim-to-rim diameter.
EN
In the 1960s demonstrated that the Ries-Steinheim craters, located in the south of Germany and tektites types moldavites are the same age. Ries crater strewnfield covers eastern Germany, the Czech Republic and northern Austria. A few old scientific studies have not given a clear answer about model creation and the actual size of moldavite strewnfield. For this reason 11 years ago created a model that was to clarify these issues.
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