Chemistry, small-scale inhomogeneity, and formation of moldavites as condensates from sands vaporized by the Ries impact

Engelhardt, Wolf von; Berthold, Christoph; Wenzel, Thomas J.; Dehner, Thomas

doi:10.1016/j.gca.2005.07.004

Cited by 44 publications

(71 citation statements)

References 22 publications

(25 reference statements)

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“…We found substantial enrichment or depletion of some elements compared to UCC (Fig. 12), discussed elsewhere (e.g., von Engelhardt et al 1987Engelhardt et al , 2005Žák et al 2016). Žák et al (2016) suggested that the chemical differences between potential source sediments and moldavites reflect a complex multistage origin of CET.…”

Section: Size Morphology and Chemical Compositionsupporting

confidence: 70%

“…Source materials of CET were identified as mineralogically and chemically variable sediments of the Upper Freshwater Molasse (Obere Süßwasser Molasse) (von Engelhardt et al 1987(von Engelhardt et al , 2005Skála et al 2009 and references therein). Recently, a possible role of organic matter has been discussed by Řanda et al (2008) and Žák et al (2012).…”

Section: Introductionmentioning

confidence: 99%

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New constraints on the Polish moldavite finds: a separate sub-strewn field of the central European tektite field or re-deposited materials?

Skála¹,

Jonášová²,

Žák³

et al. 2016

J. Geosci.

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Rusko and Mielęcin represent the most remote localities from the Ries impact structure with the distance of about 475 km. The previously published data were limited to electron-microprobe analyses of four specimens. Here we provide additional compositional data for a single moldavite from the North Stanisław sandpit near Rusko. Combined data of electron microprobe (EPMA; major elements) and laser-ablation inductively-coupled--plasma mass spectrometry (LA-ICP-MS; minor and trace elements) provide new insights into chemical variability of CET. Electron-microprobe analyses supplemented with back-scattered electron images showed marked chemical heterogeneity of the Polish moldavite on the micrometre scale, confirmed also by LA-ICP-MS. The major-element composition of the volumetrically dominating glass of the specimen is indistinguishable from the majority of c. 5000 available EPMA analyses of moldavites from other regions and, consequently, it does not provide any unambiguous link to any of these sub-strewn fields. Rare schlieren in the sample with unique Ca-Mg-rich composition have counterparts among several South Bohemian moldavites. In general, Polish moldavites are small (less than 0.5 g) irregular fragments or splinters of angular shape with multistage sculpturing. Their morphological character and paleogeography of Central Europe in the last 15 Myr suggest that they were redeposited at time of the Gozdnica Fm. sedimentation from yet unknown sub--strewn field north of the Sudetic Mountains. : moldavites, tektites, Lower Silesia, Poland, Ries impact structure, geochemistry Received: 4 December, 2015; accepted: 3 May, 2016; handling editor: E. Jelínek The online version of this article (doi: 10.3190/jgeosci.214) contains supplementary electronic material. KeywordsCentral European tektites (CET) are called moldavites. They were formed from the uppermost sedimentary rocks layer during the Ries-Steinheim impact event in Miocene. The recent occurrences of CET in several small areas (sub-strewn fields) reflect the paleogeography at the time of impact as well as further geological history of the area.

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Section: Size Morphology and Chemical Compositionsupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

New constraints on the Polish moldavite finds: a separate sub-strewn field of the central European tektite field or re-deposited materials?

Skála¹,

Jonášová²,

Žák³

et al. 2016

J. Geosci.

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“…As it was documented by numerous papers (e.g. Engelhardt et al 2005) despite the close similarity of the chemical composition in terms of the major element contents (Si, Al., Fe, Mg, Ca) of moldavites from different substrewnfields, there are some significant differences in trace element contents, which bind to different source rocks (see discussion at Randa et al 2008). Substrewnfields are partial areas, that represent a combination of the original distribution in the strewnfield and the subsequent removal and redistribution of moldavites by fluvial erosion and transport.…”

Section: Referencesmentioning

confidence: 67%

The first polish tektites: preliminary sem investigation

Brachaniec

Szopa

Karwowski

2013

Contemporary Trends in Geoscience

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Abstract.In Lower Silesia, the first Polish moldavites were discovered. To recognize the primary chemical composition and check the morphology of investigated material SE and BSE images were used. The samples show presence of vesicles, which are one of the most typical features of tektite glass. Referring to the preliminary EDS results and comparing them with literature data, it can be assumed that in all cases the base material for all known moldavites was the same.

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“…In summary, it is possible that Polish and Lusatian moldavites, despite the fact that they come from the same strewn field, could have formed from lithologically different parts of the Upper Freshwater Molasse. According to Engelhardt et al (2005) and Řanda et al (2008), the similarity of the major element contents in tektite glasses indicates very similar, but nit necessarily identical source deposits. The Upper Freshwater Molasse, the source of moldavites, contain many lenses of carbonates and clays, which may account for the observed changes in moldavite compositions.…”

Section: Chemical Compositionmentioning

confidence: 98%

“…In the 1960s, it was confirmed that moldavites are distributed over three specific areas: the Czech Republic (Bohemia, Moravia and near Cheb), Lusatia (SE Germany) and northern Austria (Trnka and Houzar 2002, and references therein). Until now, these tektites have been the subject of numerous geochemical, sedimentological and physical investigations (e.g., Knobloch et al 1981Knobloch et al , 1983Engelhardt et al 1987Engelhardt et al , 2005Koeberl et al 1988;Lange 1995;Meisel et al 1997;Stöffler et al 2002;Skála and Čada 2003;Řanda et al 2008;Buchner and Schmieder 2009;Žák et al 2012;Glass and Simonson 2013). Moldavites source impact structure is the Nördlinger Ries crater in southern Germany.…”

Section: Introductionmentioning

confidence: 99%

New moldavites from SW Poland

Brachaniec¹,

Szopa²,

Karwowski³

2016

Acta Geologica Polonica

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Large impact craters are relatively rare in geological record on the Earth. All over the world only 164 crater structures are above 1 km in diameter and only 40 with with more than 20 km in diameter (Earth Impact Database). The most notable features of such big impacts are significant pressure and temperature caused by extraterrestrial body fall. In some cases, impact may lead to glass production, which is named tektite. The distribution and chemical features of impact glasses are the most diagnostic features of the cosmic body impacts. Tektites are distal ejecta type deposits, next to three other impact melt products (Osinski 2003): (1) crystalline melt bodies in the impact structure, (2) glassy clasts in melt-bearing breccias or suevite, and (3) injection dykes in the crater. These different types of glasses form during the shock melting phase of target. Impact melt glasses resemble a terrestrial volcanic glass in appearance. There are three properties, which can be used to distinguish between the impact and terrestrial types of glasses: (1) the impact glass has a chemical composition of one lithology or mixture of different rock types that are present in the source basement (Dence 1971), (2) it is characterized by the presence of lechatelierite (Stöf-fler 1984), and (3) it has inclusions of shocked minerals (Engelhardt 1972). Characteristic shapes of tektites result from three stages of processes (Baker 1963): (1) the cooling of molten terrestrial material, (2) the flight of tektites through the atmosphere (however this stage did not occur in most of the tektites) and (3) emplacement on Earth's surface, when geochemical processes, like redeposition or weathering, finally influence the morphology of tektites.Up Będzińska Str. 60, krzysztof.szopa@us.edu.pl, lukasz.karwowski@us.edu.pl. ABSTRACT:Brachaniec, T., Szopa, K. and Karwowski, Ł. 2016. New moldavites from SW Poland. Acta Geologica Polonica, 66 (1), 99-105.Warszawa.Four newly discovered moldavites from the East and West Gozdnica pits, SW Poland, are characterized. All specimens, including other four, reported earlier, are from Upper Miocene fluvial sediments of the Gozdnica Formation. Their weight varies between 0.529 and 1.196 g. The moldavites are bottle green in colour and have bubbles and inclusions of lechatelierite. Low degree of corrosion suggests short river transport, apparently eastward from Lusatia.

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Chemistry, small-scale inhomogeneity, and formation of moldavites as condensates from sands vaporized by the Ries impact

Cited by 44 publications

References 22 publications

New constraints on the Polish moldavite finds: a separate sub-strewn field of the central European tektite field or re-deposited materials?

New constraints on the Polish moldavite finds: a separate sub-strewn field of the central European tektite field or re-deposited materials?

The first polish tektites: preliminary sem investigation

New moldavites from SW Poland

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