VÝZKUM POZDNĚ KVARTÉRNÍ AKTIVITY ZLOMU KOSÍŘE V HORNOMORAVSKÉM ÚVALU ANEB PROČ JE DOBRÉ STUDOVAT SVAHOVINY A SEISMOGRAMY
| Title in English | Late Quaternary slip at the Kosíř Fault of the Upper Morava Basin - an example of joint research using trenching and microseismic monitoring |
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| Authors | |
| Year of publication | 2015 |
| Type | Article in Periodical |
| Magazine / Source | Geologické výzkumy na Moravě a ve Slezsku |
| MU Faculty or unit | |
| Citation | |
| Field | Seismology, vulcanology, and Earth structure |
| Keywords | Upper Morava Basin; Kosíř Fault; active faulting; paleoseismology; Quaternary |
| Description | Preliminary results of a research into the late Quaternary slip of a major fault in the seismically active Upper Morava Basin are given. Three trenches, up to 6 m deep, were excavated at the foot of the Kosíř Fault scarp near Stařechovice and Čelechovice. The exposed complex sequences of colluvium and loess, now only partly dated by OSL and 14C, is heavily faulted. The faulting is explained by a tectonic slip at the Kosíř Fault and, in the Stařechovice trench, also by simultaneous slope deformations. None of the faults do offset the Holocene topsoil but the youngest of them were clearly active after the deposition of the youngest loess and indicate the slip of up to 1.4 m in Late Pleistocene. In Čelechovice trenches the minimum vertical throw of 4 m is indicated for the lower part of the sequence with assumed Late Pleistocene age. The geometry of the deformed zone suggests an oblique normal faulting with significant strike-slip component. The sense of shearing in the horizontal plane was not resolved. Minimum tectonic slip rate of 0.1-0.3 mm/year in Late Pleistocene is suggested but this must be confirmed by new dating. Our observations reveal surprisingly young and large deformation which may suggest a temporary increase of tectonic activity during Late Pleistocene. |
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