14C and U - series dating of speleothems in the Bohemian Paradise (Czech Republic): retreat rates of sandstone cave walls and implications for cave origin

Title:

14C and U - series dating of speleothems in the Bohemian Paradise (Czech Republic): retreat rates of sandstone cave walls and implications for cave origin

Creator:

Jiří Bruthans, Jana Schweigstillová, Petr Jenč, Churáčková, Zdeňka, and Petr Bezdička

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:f2454f9a-58f9-4300-9d34-af1e280ed7b6
uuid:f2454f9a-58f9-4300-9d34-af1e280ed7b6
issn:1214-9705

Subject:

Geologie. Meteorologie. Klimatologie, pískovce, jeskyně, stáří, pseudokras, eroze (geologie), holocén, sandstones, caves, old age, pseudokarst, erosion, holocene, speleothems, 7, and 551

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

Speleothems in 6 sandstone caves in the Bohemian Paradise (Český ráj) were dated by means of 14C and U-series methods. Stable isotopes of C and O, FAAS, IR, XRD, XRF and SEM were used to characterize the carbonate material and its source. Stable isotopes (C and O) composition of speleothems in two caves corresponds to values characteristic for cave speleothems in Central Europe. In other caves they indicate evaporation and fast carbon dioxide escape during carbonate precipitation. The speleothems from the Krtola Cave were deposited between 8 and 13 kyr BP. Speleothems were deposited 5-8 kyr BP in the Sintrová, Mrtvé Údolí and U Studánky caves. Calcite coatings on smooth sandstone surfaces in studied caves demonstrate that cave walls did not retreat even a few mm in the last 5-8 kyr since speleothem deposition and are thus not evolving under recent climatic conditions. Most of the cave ceilings and walls are at present time indurated by hardened surfaces, which protect the sandstone from erosion. Sandstone caves probably intensively evolved either during or at the end of the Last Glacial period. There are two different erosion mechanisms which might have formed/reshaped the caves at that time: A) In the case of permafrost conditions: Repeated freeze/melt cycles affecting sandstone pore space followed by the transport of fallen sand grains by minor temporary trickles. We expect that heat was transmitted by air circulating between the cave and the surface; B) Seepage erosion of sandstone during the melting of permafrost, prior forming of case hardening., Jiří Bruthans, Jana Schweigstillová, Petr Jenč, Zdeňka Churáčková and Petr Bezdička., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Acta geodynamica et geomaterialia : | 2012 Volume:9 | Number:1 (165)

Harvested from:

CDK

Metadata only:

false