Three Late Silurian carbonate proWles of the Malynivtsy and Skala Formations from Podolia (western Ukraine) are discussed in terms of sedimentation dynamics. Their common feature is the appearance of thick, stromatoporoid-rich beds within Wne-grained peritidal deposits. These intercalations are composed of fossils typical of oVshore sedimentary environments. In the most spectacular case, a channel, several tens of metres wide and inWlled with stromatoporoids, is incised in a peritidal cyclic complex. The successions investigated exhibit sedimentary features that are diagnostic of onshore redeposition. Independently of the scale of the recorded sedimentary events, the onshore redeposition was caused by factors with energy levels exceeding those of average storms, probably by hurricanes or even tsunami waves. The dynamic nature of some of the stromatoporoid beds has to be taken into account when constructing the curves illustrating bathymetrical and facies development of the Silurian succession of Podolia. The genesis of lens-shaped stromatoporoid beds, elongated depending on their origin, either parallel or perpendicular to the facies belts, should be considered an important factor in reconstructions of the depositional architecture of sedimentary hydrocarbon collectors.

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LETHAIAŁuczyń ski, P. 2006 12 01: Stromatoporoid shape and burial ratio changes during growth history and their methodological consequences in morphometrical analyses. Lethaia , Vol. 39, pp. 339 Á358. Oslo. ISSN 0024-1164. Eight Devonian stromatoporoids with clearly exposed arrangements of latilaminae were subjected to detailed morphometrical analyses. Distinctive sets of latilaminae were marked on photographs taken from polished specimens, which allowed reconstruction of their individual growth histories by presenting consecutive stages of their growth. The growth forms measured above the sediment surface and the overall shapes of the skeleton at a given time have proved to differ distinctly between each other throughout the growth history of these stromatoporoids. The morphometrical features of individual specimens (both of their growth forms and of their whole skeletons) distinctly changed throughout their development. Changing environmental factors directly influenced the growth form above the sea floor, and each specimen shows its own specific history of growth form changes. Instead, overall shapes of the skeleton of most of the studied specimens changed in a similar general manner resulting from growth during sediment accumulation. Basing the palaeoenvironmental considerations only on the stromatoporoids' final shapes may thus be very misleading. It is therefore suggested that the ascription of a specimen to a particular morphometrical category should be based on the mode of its growth history represented by a curve recording the V /B changes (vertical height versus basal length) during consecutive growth stages. Certain sedimentary processes have their direct reflection in the mode of stromatoporoid growth, and are recorded by the attributes of the shape profile (V /B ), and burial ratio (BR ) curves, which allows deciphering such features as, for example, periodicity of sediment supply, substrate consistency and tempo of sediment cementation. This is particularly valuable when the deposits are recrystallized and the sedimentary structures are not visible. The paper also tests the applicability of the new definitions of the parameters describing the stromatoporoid shape introduced recently by the author. I Burial ratio, measurements, ontogenesis, shape changes, stromatoporoids.

ABSTRACT:Łuczyński, P., Skompski, S. and Kozłowski, W. 2014. Stromatoporoid beds and flat-pebble conglomerates interpreted as tsunami deposits in the Upper Silurian of Podolia, Ukraine. Acta Geologica Polonica, 64 (3), 261-280. Warszawa.Tsunami deposits are currently a subject of intensive studies. Tsunamis must have occurred in the geological past in the same frequency as nowadays, yet their identified depositional record is surprisingly scarce. Here we describe a hitherto unrecognized example of probable palaeotsunamites.The Upper Silurian (Pridoli) carbonate succession of Podolia (southwestern Ukraine) contains variously developed event beds forming intercalations within peritidal deposits (shallow water limestones, nodular marls and dolomites). The event beds are represented by stromatoporoid and fine-grained bioclastic limestones, in some places accompanied by flat-pebble conglomerates. The interval with event beds can be traced along the Zbruch River in separate outcrops over a distance of more than 20 km along a transect oblique to the palaeoshoreline. The stromatoporoid beds have erosional bottom surfaces and are composed of overturned and often fragmented massive skeletons. The material has been transported landward from their offshore habitats and deposited in lagoonal settings. The flat-pebble conglomerates are composed of sub-angular micritic clasts that are lithologically identical to the sediments forming the underlying beds.Large-scale landward transport of the biogenic material has to be attributed to phenomena with very high energy levels, such as tropical hurricanes or tsunamis. This paper presents a tsunamigenic interpretation. Morphometric features of redeposited stromatoporoids point to a calm original growth environment at depths well below storm wave base. Tsunami waves are the most probable factor that could cause their redeposition from such a setting. The vastness of the area covered by parabiostromal stromatoporoid beds resembles the distribution of modern tsunami deposits in offshore settings. The stromatoporoid beds with unsorted stromatoporoids of various dimensions evenly distributed throughout the thickness of the beds and with clast-supported textures most probably represent deposition by traction. In some sections, the stromatoporoids are restricted to the lowermost parts of the beds, which pass upwards into bioclastic limestones. In this case, the finer material was deposited from suspension. The coexistence of stromatoporoid beds and flat-pebble conglomerates also allows presenting a tsunami interpretation of the latter. The propagating tsunami waves, led to erosion of partly lithified thin-layered mudstones, their fragmentation into flat clasts and redeposition as flat-pebble conglomerates.

Improving the parameterization of stromatoporoid shapes -a detailed approach to stromatoporoid morphometry PIOTR ŁUCZYŃ SKI Łuczyń ski, P. 2005 06 15: Improving the parameterization of stromatoporoid shapes -a detailed approach to stromatoporoid morphometry.