caa a22 4500 606149937 CHVBK 20210128100536.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00531-015-1155-5 doi (NATIONALLICENCE)springer-10.1007/s00531-015-1155-5 Types of soft-sediment deformation structures in a lacustrine Ploužnice member (Stephanian, Gzhelian, Pennsylvanian, Bohemian Massif), their timing, and possible trigger mechanism [Elektronische Daten] [Marcela Stárková, Karel Martínek, Radek Mikuláš, Nicholas Rosenau] The succession of Stephanian C lacustrine and fluvial facies of the Ploužnice member (Semily Formation) paleolake in the Krkonoše Piedmont Basin (northern Czech Republic) preserved in borehole Sm-1 shows five types of soft-sediment deformation structures (SSDS): (1) sediment injections (clastic dikes), (2) load structures and ball-and-pillow structures, (3) water-escape structures (discontinuous laminations, deformed wavy bedding, recumbent folding, and dish or pillar structures), (4) deformations by growth of carbonate and silica minerals during diagenesis, and (5) bioturbation. Bioturbations disturbing mechanical SSDS suggest that soft-sediment deformations may occur syndepositionally or soon after deposition. The discussed mechanical SSDS are developed in a lacustrine environment, most being in lower shoreface and offshore facies. The mechanical SSDS found in the Ploužnice lake deposits occur in all lacustrine facies associations (290SSDS horizons in a 67-m-thick succession). The cumulative thickness in cm of mechanical SSDS horizons per meter of thickness (ratio cmSSDS/m) is the highest in lower shoreface facies where it reaches from 50 up to 59.7cmSSDS/m. Offshore facies association reaches 44cmSSDS/m. Upper shoreface facies associations have 25.9 and 26.0cmSSDS/m, while nearshore/mudflat facies associations preserve from 22.5 to 20.5cmSSDS/m, and in palustrine carbonate, 13.5cm mechanical SSDS/m was found. SSDS in fluvial facies are rare (2.9cmSSDS/m). The distribution of SSDS in the Sm-1 borehole shows clear relationships to sedimentary facies and processes such as density flows or fluctuation of water level. The relationships of particular structures indicate a relative timing of formation which is as follows: sediment deposition was followed by the formation of mechanical SSDS, then by bioturbation, and finally by deformations due to early diagenetic growth of carbonates and silica. The distribution of SSDS in vertical sections and their direct relationship to sedimentary facies point to endogenic rather than external trigger mechanisms such as seismic activity. The main endogenic trigger mechanisms responsible for the origin of SSDS included a Stephanian semi-humid seasonal climate, basin morphology with relatively steep gradients, and elevated source areas, which created a conducive environment for rapid and repeated deposition of sheetfloods and hyperconcentrated flows and turbidites causing syndepositional loading. European Union, 2015 Soft-sediment deformation structures nationallicence Bioturbation nationallicence Early diagenetic carbonate nationallicence Lacustrine facies nationallicence Bohemian Massif nationallicence Stephanian C nationallicence Krkonoše Piedmont Basin nationallicence Stárková Marcela Czech Geological Survey, Klárov 3, 118 21, Prague 1, Czech Republic aut Martínek Karel Czech Geological Survey, Klárov 3, 118 21, Prague 1, Czech Republic aut Mikuláš Radek Institute of Geology, Academy of Science of the Czech Republic, Rozvojová 269, 165 02, Prague 6, Czech Republic aut Rosenau Nicholas Roy M. Huffington Department of Earth Sciences, Southern Methodist University, 3225 Daniel Avenue, 75275-0395, Dallas, TX, USA aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/5(2015-07-01), 1277-1298 1437-3254 104:5<1277 2015 104 531 https://doi.org/10.1007/s00531-015-1155-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-015-1155-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Stárková Marcela Czech Geological Survey, Klárov 3, 118 21, Prague 1, Czech Republic aut NATIONALLICENCE 700 1- Martínek Karel Czech Geological Survey, Klárov 3, 118 21, Prague 1, Czech Republic aut NATIONALLICENCE 700 1- Mikuláš Radek Institute of Geology, Academy of Science of the Czech Republic, Rozvojová 269, 165 02, Prague 6, Czech Republic aut NATIONALLICENCE 700 1- Rosenau Nicholas Roy M. Huffington Department of Earth Sciences, Southern Methodist University, 3225 Daniel Avenue, 75275-0395, Dallas, TX, USA aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/5(2015-07-01), 1277-1298 1437-3254 104:5<1277 2015 104 531