Osady turbulentnych spływów kohezyjnych w warstwach menilitowych płaszczowiny skolskiej (Karpaty fliszowe)

Stanisław Leszczyński



The paper presents the rocks with chaotic texture occurring in the Oligocene series of black and brown mud and clay schales, bedded with fine- and medium-grained sandstones occurring in thin and very thick beds ( deposits of gravitation flow) with hornstone marl, tuffite and diatomite inserts. •
Three main groups of chaotic rocks were distinguished.
1. Rocks built of disrupted, displaced mutually and plastically deformed fragments of riders of schaley and thin-bedded sandstone beds (Fig. 2A).
2. Chaotic sandstones (Fig. 2B - D) i.e. quartz sandstones rich in mud matrix with numerous mud flakes, vegetable detritus and sometimes with small bioclasts. Anywhere from ten to twenty centimeters clasts of schales, fine-grained sandstones and small clasts of coal also occur here with various frequency. Chaotic sandstones occur in individual beds (Fig. 2B) or along with sandstones poor in matrix, with no clasts, non-textured (Fig. 2C, Fig. 4, beds 2 and 3, Fig. 5 beds 1 and 2) or horizontally laminated beds (Fig. 2D, Fig. 5, bed 4). Chaotic sandstones beds occur in layers of several tens centimeters thick, rarely more.
3. Chaotic mudstones i.e. mudstones where quartz grains of 2 mm in diameter and bioclasts are disposed chaotically. Clasts of schales, sandstones and of coal occur individually. Mudstones are packfull with plant detritus. Thickness of chaotic mudstones is in the range of 25 - 50 cm. Chaotic • mudstones form independent beds (Fig. 3A) with sometimes schists with large particles (Fig. 3B, Fig. 5, bed 5) in the roof or even vertically laminated sandstones passing in the upper part into schales (Fig. 3C, Fig. 4, bed 4). A partion of chaotic mudstones form beds with a sandstone layer in the lower part (Fig. 3D, Fig. 4, bed 1, Fig. 5, beds 2 and 3).
Rocks of the first group are thought to be built of a scree material, while rocks of groups 2 and 3 - cohesion flow-origin deposits. In the roof chaotic sandstones and mudstones consist of a bed of schales devoid of coarse fractions and sandstone laminae deposited from the flows diluted from above, probably from a weak turbulence flow, above which the diluted suspension currents developed. Chaotic sandstones and mudstones passing downward into sandstones poor in matrix were deposited from flows that enabled segregation i.e. from a strong-turbulence flow. These flows were intermediate between typical cohesion flows and suspension currents.

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