Gothic-Arch Calcite from Speleothems of the Bohemian Karst (Czech Republic): Its Occurrence, Microscopic Ultrastructure and Possible Mechanism of Growth

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F21%3A00545192" target="_blank" >RIV/61389005:_____/21:00545192 - isvavai.cz</a>

Alternative codes found

RIV/67985891:_____/21:00545192 RIV/00216208:11310/21:10431321

Result on the web

<a href="https://doi.org/10.3390/min11080866" target="_blank" >https://doi.org/10.3390/min11080866</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/min11080866" target="_blank" >10.3390/min11080866</a>

Result language

angličtina

Original language name

Gothic-Arch Calcite from Speleothems of the Bohemian Karst (Czech Republic): Its Occurrence, Microscopic Ultrastructure and Possible Mechanism of Growth

Original language description

Gothic arch calcite, a specific crystallographic variety of calcite known from some hot springs and tufa streams, has been newly recognized in the Koneprusy Caves. The gothic-arch calcite occurs on the exteriors of exotic coralloid speleothems where it coexists with scalenohedral (dogtooth) spar crystals. The crystals exhibit microscopic ultrastructural features including deeply eroded topography, etch pits, and spiky and ribbon calcite crystallites, pointing to its extensive natural etching. Many gothic-arch calcites originated as late-stage, secondary overgrowths on older, etched dogtooth calcite crystals. Its characteristic outward curvature resulted from the recrystallization of etching-liberated fine carbonate grains and newly formed needle-fiber calcite laths, which were accumulated and bound on the faces and at the bases of corroded crystals. These intimately coexisting destructive and constructive processes of carbonate crystal corrosion and growth were probably mediated by bacteria, fungi, or other microorganisms. Fluid inclusions embedded in calcite crystals point to a vadose setting and temperatures below similar to 50 degrees C. This, combined with the wider geological context, indicates that the gothic arch calcite crystals originated only during the late Pleistocene to Holocene epochs, when the cave, initially eroded by hypogene fluids in the deeper subsurface, was uplifted to the subaerial setting and exposed to the meteoric waters seeping from the topographic surface. The radiocarbon analysis shows that gothic-arch calcite crystals are generally older than similar to 55,000 years, but the surface layers of some crystals still reveal a weak C-14 activity, suggesting that microbiologically mediated alterations of the speleothems may have been occurring locally until now.

Czech name

—

Czech description

—

Type

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

CEP classification

—

OECD FORD branch

20703 - Mining and mineral processing

Project

<a href="/en/project/EF16_019%2F0000728" target="_blank" >EF16_019/0000728: Ultra-trace isotope research in social and environmental studies using accelerator mass spectrometry</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

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

Name of the periodical

Minerals

ISSN

2075-163X

e-ISSN

2075-163X

Volume of the periodical

11

Issue of the periodical within the volume

8

Country of publishing house

CH - SWITZERLAND

Number of pages

23

Pages from-to

866

UT code for WoS article

000689547400001

EID of the result in the Scopus database

2-s2.0-85112209371