Two Holocene impact craters at Emmerting, Germany: deformation, fracturing, and their relationships to the melting and decarbonization

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F25%3A10500462" target="_blank" >RIV/00216208:11310/25:10500462 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=VlkF6-V0-i" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=VlkF6-V0-i</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.23939/jgd2025.01.005" target="_blank" >10.23939/jgd2025.01.005</a>

Result language

angličtina

Original language name

Two Holocene impact craters at Emmerting, Germany: deformation, fracturing, and their relationships to the melting and decarbonization

Original language description

In two craters near Emmerting, three major processes which variably affected the original pebbles are documented in the following order: 1. Deposition of hot material which solidified to glass (usually thin and transparent) or reacted with carbonate to form expanded &quot;pumice&quot; on the surface of pebbles. 2. Ductile deformation of variable intensity (with limited fragile deformation but intense fracturing of mineral grains), using older as well as newly formed discontinuities; in some cases this deformation had to be associated with extreme strain, excluding interpretation of the crater formation by any plausible human activity. The largely ductile character of deformation points to a high temperature, but it was not necessarily accompanied by melting. 3. Solidification of melts generated within pebbles or derived from secondary projectiles. These disequilibrium melts were hot enough to have very low viscosity (in some cases, they may have also been injected by high pressure/strain, or sucked in), which enabled them to fill even thin fractures in individual mineral grains; gas expansion also formed extrusions resembling miniature volcanic features on the surface of some pebbles. In one zircon grain baddeleyite was observed, probably formed by shock metamorphism. However, no additional evidence was found to suggest pressures exceeding the threshold typically required for shock-induced melting (approx. 8 Gpa or more). Nevertheless, the energy transformed during repeated mutual collisions may have heated the interior of pebbles sufficiently. Origin of the depression at Grabenstatt-Kaltenbach is unclear, the disequilibrium melting and decarbonization may also be explained by anthropogenic processes.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10505 - Geology

Project

<a href="/en/project/GA23-06075S" target="_blank" >GA23-06075S: Environmental changes caused by extraterrestrial impacts and volcanism: Evidence from lake sediments</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2025

Confidentiality

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

Name of the periodical

Geodinamìka

ISSN

1992-142X

e-ISSN

2519-2663

Volume of the periodical

38

Issue of the periodical within the volume

1

Country of publishing house

UA - UKRAINE

Number of pages

20

Pages from-to

5-24

UT code for WoS article

001534161700001

EID of the result in the Scopus database

2-s2.0-105011172585