Electrical resistivity imaging of anastomosing river subsurface stratigraphy and possible controls of fluvial style change in a graben-like basin, Czech Republic

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F18%3A73590912" target="_blank" >RIV/61989592:15310/18:73590912 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0169555X1830206X" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0169555X1830206X</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.geomorph.2018.05.012" target="_blank" >10.1016/j.geomorph.2018.05.012</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Electrical resistivity imaging of anastomosing river subsurface stratigraphy and possible controls of fluvial style change in a graben-like basin, Czech Republic

Popis výsledku v původním jazyce

Subject to frequent channel avulsions due to the increased frequency of floods, rise of base level, and/or sediment overloading, anastomosing rivers are sensitive to external (climatic or tectonic) forcing in sedimentary basins. The Morava River, Czech Republic, shows a well-developed Holocene anastomosis, confined to the pull-apart type Upper Morava Basin (UMB). We studied the stratigraphy and aggradation rates of the UMB using electrical resistivity tomography (ERT), dipole electromagnetic profiling (DEMP), core data, and radiocarbon ages, with the aim of identifying factors triggering the anastomosis at the Pleistocene/Holocene transition. The ERT and DEMP proved to be excellent tools to visualize the shape and thickness of floodplain depositional units (abandoned meanders, scroll bars, etc.). The major geophysical surfaces identified are the base of the late Weichselian braided stream deposits (OSL age = 34.53 +/- 3.42 ka), interpreted as a palaeo-stream gradient of the Morava River, and their transition to Holocene floodplain deposits. In the late Weichselian, the river aggraded at an average rate of 0.2 mm/yr. The Holocene (oldest C-14 age = 7.066 +/- 0.072 ka) short-term aggradation rates reached up to 13.7 mm/yr, but the average long-term rates (similar to 0.07 to similar to 0.4 mm/yr) are comparable to the late Weichselian. The stratigraphy and sediment ages indicate that the onset of anastomosis was not likely associated with accelerated basin subsidence. Possible controls of the anastomosis include upstream control by numerous tributaries, large wood debris in the floodplain forests, and changes in land use. The tectonic and geomorphic context of the UMB pull-apart basin probably favoured the development of the anastomosis.

Název v anglickém jazyce

Electrical resistivity imaging of anastomosing river subsurface stratigraphy and possible controls of fluvial style change in a graben-like basin, Czech Republic

Popis výsledku anglicky

Subject to frequent channel avulsions due to the increased frequency of floods, rise of base level, and/or sediment overloading, anastomosing rivers are sensitive to external (climatic or tectonic) forcing in sedimentary basins. The Morava River, Czech Republic, shows a well-developed Holocene anastomosis, confined to the pull-apart type Upper Morava Basin (UMB). We studied the stratigraphy and aggradation rates of the UMB using electrical resistivity tomography (ERT), dipole electromagnetic profiling (DEMP), core data, and radiocarbon ages, with the aim of identifying factors triggering the anastomosis at the Pleistocene/Holocene transition. The ERT and DEMP proved to be excellent tools to visualize the shape and thickness of floodplain depositional units (abandoned meanders, scroll bars, etc.). The major geophysical surfaces identified are the base of the late Weichselian braided stream deposits (OSL age = 34.53 +/- 3.42 ka), interpreted as a palaeo-stream gradient of the Morava River, and their transition to Holocene floodplain deposits. In the late Weichselian, the river aggraded at an average rate of 0.2 mm/yr. The Holocene (oldest C-14 age = 7.066 +/- 0.072 ka) short-term aggradation rates reached up to 13.7 mm/yr, but the average long-term rates (similar to 0.07 to similar to 0.4 mm/yr) are comparable to the late Weichselian. The stratigraphy and sediment ages indicate that the onset of anastomosis was not likely associated with accelerated basin subsidence. Possible controls of the anastomosis include upstream control by numerous tributaries, large wood debris in the floodplain forests, and changes in land use. The tectonic and geomorphic context of the UMB pull-apart basin probably favoured the development of the anastomosis.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA17-06229S" target="_blank" >GA17-06229S: Vývoj sedimentace v přehradních nádržích jako antropogenních bariérách v říčních systémech: od materiálové bilance po osud polutantů</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

GEOMORPHOLOGY

ISSN

0169-555X

e-ISSN

—

Svazek periodika

317

Číslo periodika v rámci svazku

SEP

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

18

Strana od-do

139-156

Kód UT WoS článku

000440120600011

EID výsledku v databázi Scopus

2-s2.0-85048473948