Evaluation of climatic and tectonic imprints in fluvial successions of an early Permian depositional system (Asselian Vrchlabí Fm., Krkonoše Piedmont Basin, Czech Republic)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F22%3A00000010" target="_blank" >RIV/00025798:_____/22:00000010 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.geoscienceworld.org/sepm/jsedres/article/92/3/275/612946/Evaluation-of-Climatic-and-Tectonic-Imprints-In" target="_blank" >https://pubs.geoscienceworld.org/sepm/jsedres/article/92/3/275/612946/Evaluation-of-Climatic-and-Tectonic-Imprints-In</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.2110/jsr.2020.137" target="_blank" >10.2110/jsr.2020.137</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Evaluation of climatic and tectonic imprints in fluvial successions of an early Permian depositional system (Asselian Vrchlabí Fm., Krkonoše Piedmont Basin, Czech Republic)

Popis výsledku v původním jazyce

The Krkonoše Piedmont Basin (KPB), an early post-Variscan basin (c. 310–280 Ma)located in the northern Czech Republic, contains up to 300 m thick non-marine lower Permian deposits in its southern-central part. The early Permian KPB exhibits striking similarities to other early Variscan, near equatorial basins in terms of tectonostratigraphic evolution. This work focuses on sedimentological analysis of the Vrchlabí Fm. (Asselian) in the SW part of the KPB. In the southern-central KPB, the formation consists of fluvio-deltaic deposits, which laterally pass into lacustrine deposits derived from lake Rudník in the northern part of the KPB. Fluvial deposits comprise sandstone and conglomeratic bodies interpreted as single- and multi-storey channel fills as well as various macroforms (e.g., bars) deposited by a braided fluvial system. Vertically, fluvial successions are divided into five different units that exhibit variable ratios between preserved channel fill and floodplain deposits (reflecting differing accommodation/supply ratio) and contrasting channel-fill geometries. In order to explain the observed changes in the fluvial style and to determine the controlling factors, the interaction of the fluvial system with the lacustrine basin was investigated by interpreting base-level changes of the fluvial system, as well as tracing horizons of lake expansion (allegedly a result of humid periods). In the central part of the KPB, the transition from fluvial to lacustrine deposits is represented by alternating grey sandstone and dark grey siltstone/mudstone beds, deposited either as mouth bars or bottomsets of lacustrine microdeltas. Detailed correlation of existing borehole data and newly acquired outcrop gamma-ray logs led to better understanding of lateral and vertical relationships between the fluvial, the ‘transitional’ and the lake facies at the basin-scale. Altough initial tectonic subsidence played a substainal role during the intialdeposition of the formatio, the observed pattern cannot be explained merely by tectonics. The external geometries and internal architecture of fluvial channel bodies, variable degree of floodplain preservation together with inferred decelerated fault subsidence indicate that changes in fluvial style through time were significantly controlled by climate variations. This study illustrates the usefulness of an interdisciplinary approach to reconstruct a basin’s early Permian stratigraphic history in a region with sparse outcrops and very limited fossil record.

Název v anglickém jazyce

Evaluation of climatic and tectonic imprints in fluvial successions of an early Permian depositional system (Asselian Vrchlabí Fm., Krkonoše Piedmont Basin, Czech Republic)

Popis výsledku anglicky

The Krkonoše Piedmont Basin (KPB), an early post-Variscan basin (c. 310–280 Ma)located in the northern Czech Republic, contains up to 300 m thick non-marine lower Permian deposits in its southern-central part. The early Permian KPB exhibits striking similarities to other early Variscan, near equatorial basins in terms of tectonostratigraphic evolution. This work focuses on sedimentological analysis of the Vrchlabí Fm. (Asselian) in the SW part of the KPB. In the southern-central KPB, the formation consists of fluvio-deltaic deposits, which laterally pass into lacustrine deposits derived from lake Rudník in the northern part of the KPB. Fluvial deposits comprise sandstone and conglomeratic bodies interpreted as single- and multi-storey channel fills as well as various macroforms (e.g., bars) deposited by a braided fluvial system. Vertically, fluvial successions are divided into five different units that exhibit variable ratios between preserved channel fill and floodplain deposits (reflecting differing accommodation/supply ratio) and contrasting channel-fill geometries. In order to explain the observed changes in the fluvial style and to determine the controlling factors, the interaction of the fluvial system with the lacustrine basin was investigated by interpreting base-level changes of the fluvial system, as well as tracing horizons of lake expansion (allegedly a result of humid periods). In the central part of the KPB, the transition from fluvial to lacustrine deposits is represented by alternating grey sandstone and dark grey siltstone/mudstone beds, deposited either as mouth bars or bottomsets of lacustrine microdeltas. Detailed correlation of existing borehole data and newly acquired outcrop gamma-ray logs led to better understanding of lateral and vertical relationships between the fluvial, the ‘transitional’ and the lake facies at the basin-scale. Altough initial tectonic subsidence played a substainal role during the intialdeposition of the formatio, the observed pattern cannot be explained merely by tectonics. The external geometries and internal architecture of fluvial channel bodies, variable degree of floodplain preservation together with inferred decelerated fault subsidence indicate that changes in fluvial style through time were significantly controlled by climate variations. This study illustrates the usefulness of an interdisciplinary approach to reconstruct a basin’s early Permian stratigraphic history in a region with sparse outcrops and very limited fossil record.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Journal of Sedimentary Research

ISSN

1527-1404

e-ISSN

—

Svazek periodika

92

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

28

Strana od-do

275-303

Kód UT WoS článku

000787774000004

EID výsledku v databázi Scopus

2-s2.0-85131098381