The First Finding of Armored Mud Balls in Turkmenistan

The so-called armored mud balls, which represent a firm mechanical combination of clayey and sandy–clastic rocks, are found in ephemeral stream channels of arid low-mountain areas. The most striking feature of these structures is their spherical, ball-shaped form. They were first reported from California and Arizona as early as more than a century ago (Jones and Kind, 1875). The balls in these areas range in size from 5 to 40 cm across. They are composed of mud, agglutinated debris, gravel, and sand. Due to high strength and round form, they were named as armored mud balls (Bell, 1940). American researchers inferred that armored mud balls are encountered in North American deserts more often in streams with a marked gradient, mainly in conditions of the medium- and low-mountain relief. In their opinion, mud balls formed as a result of the activity of short-lived but intense water streams in valleys during heavy rains and snow melting.     

The trophic position of the alien crab <Emphasis Type="Italic">Rhithropanopeus harrisii</Emphasis> (crustacea decapoda panopeidae) in the Taman Bay,Sea of Azov community

This work concerns the trophic web positioning of the alien crab Rhithropanopeus harrisii and other common marine invertebrate species and fishes in the benthic ecosystem of the shallows of Taman Bay, Sea of Azov. The base of the trophic web in this system is composed of phytoplankton, macrophytes (algae and marine grasses), and reeds that use atmospheric carbon for photosynthesis. Analysis of the isotopic composition of nitrogen and carbon has shown that although marine grasses are dominating primary producers in the shallows of the bay, primary consumers (such as Cerastoderma glaucum, Porifera gen. sp., Gammarus aequicauda, Deshayesorchestia deshayesii and Idotea balthica) only partially use this organic source; instead, they use a combination of different sources of primary production. It has been shown that the food source of the alien crab is primarily of animal origin. In Taman Bay, R. harrisii is on the same trophic level as other carnivores/scavengers: benthic fishes Syngnathus nigrolineatus, Gobius spp. and native crab Pilumnus hirtellus and shrimp Palaemon adspersus.     

Coastal-Marine Accumulative Forms in Neogene Carbonate Sediments with the Transcaspian Region as Example

The relief of high limestone plateaus of the Transcaspian region (Ustyurt, Steppe Mangyshlak, and Krasnovodsk) is leveled and primarily tectonic: ridges and depressions (tens and hundreds of kilometers in length and tens, rarely a few hundred meters in amplitude) are composed of gentle (10–40) positive and negative deformations of the Neogene cover. The plateaus are bounded by ledges (chinoks). Against the background of the gentle hilly topography, one can observe smaller but sufficiently long (tens of kilometers) groups of arc-shaped parallel limestone ridges (2–8 m high) that crosscut large morphological irregularities. All topographic forms on the plateau resulted from a prolonged (many millions years) weathering and arid denudation. Therefore, insignificant differences of stability appeared in limestones armoring the plateau. Analysis of the composition and structure of limestones in linear arc-shaped ridges of ledges and the plateau surface showed that the limestones represent an extremely shallow-water facies of shelf sediments. The arc-shaped limestone ridges on the plateau are exposed, partially modified, accumulative, and biogenic-accumulative forms of bottom relief. Similar accumulative forms coupled with biogenic buildups are known in nontropic carbonate shelves of recent seas. The finding of coastal-marine forms on the limestone plateau surface suggests a shallow-water sedimentation regime in Neogene basins persisting over short time spans. Study of such forms is of interest for the refinement of water depths, wave–wind regime, and currents in Neogene basins, as well as for prospecting for oil–gas fields and placer accumulations.