Two impact craters at Emmerting, Germany: field documentation and geophysics

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F24%3A00605434" target="_blank" >RIV/61389005:_____/24:00605434 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68145535:_____/24:00605434 RIV/00216208:11310/24:10493592 RIV/68407700:21340/24:00378856

Výsledek na webu

<a href="https://science.lpnu.ua/jgd/all-volumes-and-issues/2372024/two-impact-craters-emmerting-germany-field-documentation-and" target="_blank" >https://science.lpnu.ua/jgd/all-volumes-and-issues/2372024/two-impact-craters-emmerting-germany-field-documentation-and</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.23939/jgd2024.02.027" target="_blank" >10.23939/jgd2024.02.027</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Two impact craters at Emmerting, Germany: field documentation and geophysics

Popis výsledku v původním jazyce

New research of two craters at Emmerting (No. 4 and No. 5), Germany, is presented. This paper should be the first part of two papers concerning presumed impact craters at Emmerting. The second paper will be about mineralogical/petrological, temperature and stress analyses. The enstatite-dominated meteoritic material, found in the crater No. 4 [Procházka et al., 2022. Procházka, 2023], is the subject of a separate detailed research. High-temperature effects and extreme deformation are significant in both craters. This deformation is explained with the effects of pressure wave(s) and later decompression in a target dominated by large but unconsolidated pebbles. Mutual collisions and secondary projectiles were documented. While most pebbles in the Crater No. 4 were thermally affected, the fine-grained fraction of the filling is poor in such material. It follows that small particles were volatilized and/or blown away during crater formation, or transported away later (e.g., by groundwater). Gamma-ray spectrometry has indicated that the walls of Crater No. 4 are significantly enriched in major natural radionuclides of Th, K and partly U, while the crater interior is depleted in these elements which are concentrated mainly in fine-grained fractions. This suggests a selective removal and volatilization of fine-grained material during the crater formation. The georadar measurements at both craters show that crater rims (walls) were partly pushed from below and partly heaped up from above with material that came from the crater interior. Georadar detected a compact body below the crater floor which is supported by results of resistivity measurements. A set of geophysical, geochemical, microscopic and mineralogical measurements proved that the craters at Emmerting are of impact origin. Extreme high temperature (HT) conditions inside the crater and small diameter of both craters indicate possible existence of very small meteoroids that are able to penetrate Earth´s atmosphere with high impact velocity (more than 30 km/s). This fact should challenge current models of bolide penetration through atmosphere.

Název v anglickém jazyce

Two impact craters at Emmerting, Germany: field documentation and geophysics

Popis výsledku anglicky

New research of two craters at Emmerting (No. 4 and No. 5), Germany, is presented. This paper should be the first part of two papers concerning presumed impact craters at Emmerting. The second paper will be about mineralogical/petrological, temperature and stress analyses. The enstatite-dominated meteoritic material, found in the crater No. 4 [Procházka et al., 2022. Procházka, 2023], is the subject of a separate detailed research. High-temperature effects and extreme deformation are significant in both craters. This deformation is explained with the effects of pressure wave(s) and later decompression in a target dominated by large but unconsolidated pebbles. Mutual collisions and secondary projectiles were documented. While most pebbles in the Crater No. 4 were thermally affected, the fine-grained fraction of the filling is poor in such material. It follows that small particles were volatilized and/or blown away during crater formation, or transported away later (e.g., by groundwater). Gamma-ray spectrometry has indicated that the walls of Crater No. 4 are significantly enriched in major natural radionuclides of Th, K and partly U, while the crater interior is depleted in these elements which are concentrated mainly in fine-grained fractions. This suggests a selective removal and volatilization of fine-grained material during the crater formation. The georadar measurements at both craters show that crater rims (walls) were partly pushed from below and partly heaped up from above with material that came from the crater interior. Georadar detected a compact body below the crater floor which is supported by results of resistivity measurements. A set of geophysical, geochemical, microscopic and mineralogical measurements proved that the craters at Emmerting are of impact origin. Extreme high temperature (HT) conditions inside the crater and small diameter of both craters indicate possible existence of very small meteoroids that are able to penetrate Earth´s atmosphere with high impact velocity (more than 30 km/s). This fact should challenge current models of bolide penetration through atmosphere.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10406 - Analytical chemistry

Projekt

<a href="/cs/project/GA23-06075S" target="_blank" >GA23-06075S: Environmentální změny způsobené extraterestrickými impakty a vulkanismem: Doklady v jezerních sedimentech</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Geodynamics

ISSN

1992-142X

e-ISSN

2519-2663

Svazek periodika

2

Číslo periodika v rámci svazku

37

Stát vydavatele periodika

UA - Ukrajina

Počet stran výsledku

18

Strana od-do

27-44

Kód UT WoS článku

001424782300003

EID výsledku v databázi Scopus

2-s2.0-85217463869