Intrusions of coherent volcanic rocks as reason, why eroded diatremes may form positive topography: an example of Bídnice diatreme, Czech Republic

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985891%3A_____%2F24%3A00603888" target="_blank" >RIV/67985891:_____/24:00603888 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11310/24:10489434 RIV/00025798:_____/24:10169383

Result on the web

<a href="https://doi.org/10.3190/jgeosci.396" target="_blank" >https://doi.org/10.3190/jgeosci.396</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3190/jgeosci.396" target="_blank" >10.3190/jgeosci.396</a>

Result language

angličtina

Original language name

Intrusions of coherent volcanic rocks as reason, why eroded diatremes may form positive topography: an example of Bídnice diatreme, Czech Republic

Original language description

The Bídnice hill near Litoměřice, Czech Republic, has been recognized as a volcanic structure during a survey for a new railway connection between Prague and Dresden, where after several campaigns of combined geophysical survey, it has been concluded, that Bídnice is actually a deeply eroded peanut-shaped maar-diatreme volcano forming a positive morphology. The reason for the higher resistance of the disintegrated rock in the diatreme fill against the erosion when compared to surrounding country rocks was the main question of our presented research. While other positive-morphology diatremes in the region are mostly associated with high-viscosity differentiated alkaline rocks (namely phonolites), the Bídnice diatreme comprises intrusions of basic rock (SiO2 ca 38 wt. %), classified as olivine nephelinite. From the geophysical survey of the internal structure, comprising magnetometry and electrical resistivity tomography, a spoon-like subsurface intrusions of the olivine nephelinite were found. A smaller outcrop of the intrusive system penetrating the diatreme provided a K–Ar age of 27.06 ± 0.57 Ma (Oligocene). The results of the geophysical survey were then used to create a 3D geological model to better understand and interpret the geological setting. A system of coherent sills, even with a rather low thickness in the case of low-viscosity (ultra)mafic rocks, may be responsible for the reinforcement of the diatreme leading in slower erosion, and therefore resulting in the significant positive topography of eroded maar-diatreme volcano. In addition, sub-horizontal intrusions provide more homogeneous reinforcement of the diatreme against erosion compared to subvertical dykes, those would be exposed by the selective erosion in the form of small ridges. © 2024, Czech Geological Survey. All rights reserved.

Czech name

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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

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OECD FORD branch

10505 - Geology

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Journal of Geosciences

ISSN

1802-6222

e-ISSN

1803-1943

Volume of the periodical

69

Issue of the periodical within the volume

3

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

15

Pages from-to

183-197

UT code for WoS article

001382486700005

EID of the result in the Scopus database

2-s2.0-85213355414