Central Kyzylkum Desert Research Articles

Pterosphenus muruntau – valid species of sea snakes (Squamata: Palaeophiidae) from the middle Eocene of Uzbekistan

A palaeophiid sea snake Pterosphenus muruntau Averianov, 1997 was based on two trunk vertebrae and several vertebral fragments from the middle Eocene (Bartonian) coastal marine deposits of Dzheroi 2 locality in the Central Kyzylkum Desert, Uzbekistan. The species was considered a nomen dubium by Rage and coauthors in 2003 based on alleged poor preservation of the type specimens. However, the preservation of the holotype of P. muruntau is sufficient to discern a slightly laterally compressed vertebra and a low pterapophysis, the characters that distinguish this species from the other species of Pterosphenus. These characters are also clear in a new and better preserved vertebra of P. muruntau from the type locality. Pterosphenus muruntau should be considered a valid species of the genus Pterosphenus.

Regularities of ore gold placement in central kyzylkumakh (South Tyan-shan)

The article discusses the patterns of distribution of gold mineralization in the Central Kyzylkum desert of the Southern Tien Shan. As a result of applying the methods of statistical metallogenic analysis, quantitative characteristics of the localization of gold-bearing objects were obtained, explaining some of the features of their formation in connection with the stages of the geological development of the region. It was found that the formation of the gold source and the gold deposits of the Central Kyzyl Kum itself involved all stages, from the stage of formation of the oceanic crust in the spreading zones to the stage of collision and associated metamorphism.

Chemical composition of single-sided phosphoric fertilizers obtained from balanced phosphorite ore of central kyzylkum by phosphoric acid activation with sulfuric acid addition

In this study, the process of activation of off-balance phosphorite ore of the Central Kyzylkum desert (14,33% P205) by extraction phosphoric acid (14,32% P205) with the addition of sulfuric acid (93%) at 75 °C, reaction time 30 min. at different mass ratios P205PAE: P205FC andP205PAE : H2SO4mng. It is shown that the addition of H2SO4 significantly intensifies the process of phosphoric acid activation of the phosphate mineral of the raw material. The water-insoluble part of the products of phosphoric acid activation with the addition of sulfuric acid has been studied. It has been shown that both the fertilizer itself and it’s water-insoluble part contain a significant amount of the P2O5 form assimilable for plants.

The discovery of Eifelian ammonoids in the Central Kyzylkum Desert (Aristantau Mountains, Uzbekistan)

Eifelian ammonoids are described for the first time from the Central Kyzylkum Desert (Uzbekistan, Navoiy Region, Aristantau Mountains). The ammonoid assemblage includes the typical Eifelian genera Fidelites, Subanarcestes (a new species S. aristanensis Nikolaeva sp. nov. is described), and Cabrieroceras, found in association with brachiopods, conodonts, and dacryoconarids. The ammonoid assemblage is similar to that from the Chotec beds of Barrandien and their equivalents in the Urals, Salair, Germany, and Morocco (Subanarcestes macrocephalus Zone), suggesting a connection between the Eifelian Kyzylkum Basin, which was part of the Turkestan Paleoocean, and European, North African, Siberian, and Uralian basins. The ammonoids studied are not associated with black shale and apparently existed in normal marine environments.

Troodontidae (Dinosauria: Theropoda) from the Upper Cretaceous of Uzbekistan

To date three taxa of troodontid theropod dinosaurs have been recognized from Upper Cretaceous strata in two regions of the Kyzylkum Desert in Uzbekistan. The Cenomanian Khodzhakul Formation in the southwestern Kyzylkum Desert has yielded isolated serrated teeth and some postcranial bones of an indeterminate troodontid. In the central Kyzylkum Desert troodontids are known from the Cenomanian Dzharakuduk Formation (Urbacodon itemirensis) and the Turonian Bissekty Formation (Urbacodon sp.). Urbacodon itemirensis is known from a single dentary whereas Urbacodon sp. is represented by isolated teeth, maxilla and dentary fragments, a partial braincase, and some postcranial bones. The troodontid affinities of Urbacodon are supported by several synapomorphies: presence of a subotic recess; reduced basal tubera placed directly under the occipital condyle; maxilla participating in the margin of the external naris; nutrient foramina on dentary situated within a deep lateral groove; dentary without distinct interdental plates; large number of small dentary and maxillary teeth; teeth constricted between root and crown; anterior dentary teeth smaller, more numerous, more closely spaced than those in the middle of the tooth row, and implanted in a groove; posterior dorsal vertebrae with tall and posterodorsally tapering neural spines; and presence of a midline sulcus on the neural arches of distal caudals. Among Troodontidae, Urbacodon resembles Byronosaurus, Gobivenator, and Xixiasaurus in the absence of serrations on the tooth crowns and having premaxillary teeth that are D-shaped in cross-section. However, phylogenetic analysis did not recover a clade of Asiatic troodontids with unserrated teeth.

New data on the morphology and age of the bryozoans of the genus Onychocella from the Campanian-Maastrichtian of Turkmenistan and Uzbekistan

The bryozoan of the collection from the Campanian-Maastrichtian of the Pitnyak group of uplifts in Turkmenistan and the central Kyzyl Kum Desert in Uzbekistan is revised. The bryozoan species, recently identified as Onychocella spinata Favorskaja, 1980 (order Cheilostomata), are shown to belong to two species: O. spinata and O. exilis sp. nov. The new species is described, and the original description of O. spinata is complemented. The nannofossil assemblage of the sediments of the Pitnyak Uplifts enclosing O. spinata is studied, that showed Lower Campanian age of, these sediments. Thus, O. spinata should have a wider stratigraphic range of Early Campanian-Late Maastrichtian. Since no nannofossils have been recorded in the sediments of the central Kyzyl Kum Desert enclosing O. exilis sp. nov., the stratigraphic range of this species should be restricted to the Maastrichtian.

Titanosauria (Dinosauria, Sauropoda) from the Upper Cretaceous (Turonian) Bissekty Formation of Uzbekistan

ABSTRACTExposures of the Bissekty Formation (Upper Cretaceous: middle–upper Turonian) at Dzharakuduk in the central Kyzylkum Desert of Uzbekistan have yielded abundant dinosaurian remains. We report here on cranial and postcranial remains that can be attributed to titanosaurian sauropods. This material is of considerable interest in view of the relative scarcity of sauropod fossils from the Upper Cretaceous of Central Asia. An incomplete braincase originally assigned to the ceratopsian Turanoceratops tardabilis actually belongs to a derived titanosaurian. It shares a number of features (including broad basal tubera and presence of wide depression between basal tubera) with braincases of various derived titanosaurian taxa from Asia and South America. Computed tomographic (CT) scanning of the braincase permitted digital reconstruction of a partial endocast. Overall, this endocast resembles those of other sauropods, although the pituitary fossa is considerably swollen. As in other derived titanosaurians, the abducens nerve passed lateral to the pituitary fossa. The inner ear resembles that of some other titanosaurs in having a very short lateral semicircular canal and that the anterior semicircular canal is only slightly longer than the posterior one. Isolated sauropod teeth from Dzharakuduk have slender, ‘pencil-shaped’ crowns, which often bear high-angle apical wear facets. The caudal vertebrae are gently opisthocoelous rather than procoelous, as is typically the condition on at least the anterior caudals in many other titanosaurs. An anterior caudal vertebra shows extensive pneumatization of its neural arch. The sauropod remains from the Bissekty Formation establish the presence of titanosaurians in Central Asia during the Turonian.

The earliest calcified opercula of bryozoans of the order Cheilostomata

The earliest known calcified opercula are described in cryptocystidean anascan cheilostome bryozoans: Onychocella inelegans (Lonsdale, 1850) from the Lower-Upper boundary beds of the Campanian of the western Kopet Dag Range and O. spinata Favorskaja, 1980 from the Maastrichtian of the central Kyzyl Kum Desert. It is supposed that these opercula consisted of two layers: a calcified rigid basal plate (modified cryptocyst) and membranous cover (continuation of the frontal membrane). In addition, opercular scars on the perforated closure plates are described for the first time in Tamanicella panagiensis Viskova et Koromyslova, 2012 from the Late Miocene (Tortonian, Lower Maeotian) of the Taman Peninsula. It is obvious that the opercula of T. panagiensis consisted of a single membranous layer with chitinized free edges.

Skeletal remains of Tyrannosauroidea (Dinosauria: Theropoda) from the Bissekty Formation (Upper Cretaceous: Turonian) of Uzbekistan

There exists a major gap in the fossil record of tyrannosauroid theropod dinosaurs spanning the early part of the Late Cretaceous. We report on skeletal remains referable to Tyrannosauroidea indet. from the Turonian Bissekty Formation at Dzharakuduk in the central Kyzylkum Desert of Uzbekistan. Phylogenetic analysis of the hypodigm places the Bissekty tyrannosauroid as a non-tyrannosaurid tyrannosauroid more basal than the Campanian tyrannosauroids Appalachiosaurus and Bistahieversor from North America.

Mammals from the Upper Cretaceous Aitym Formation, Kyzylkum Desert, Uzbekistan

The Upper Cretaceous (?Santonian) Aitym Formation in the central Kyzylkum Desert, Uzbekistan, produced remains of a cimolodontan multituberculate ( Uzbekbaatar wardi), a spalacotheriid symmetrodont (cf. Shalbaatar sp.), a deltatheroidan (cf. Deltatherus sp.), possibly the asioryctithere aff. Daulestes sp., possibly two zalambdalestids ( Kulbeckia sp. cf. K. kulbecke and aff. Kulbeckia sp.), two supposed lipotyphlans ( Paranyctoides sp. cf. P. aralensis and Paranyctoides sp.), and zhelestid ungulatomorphs (cf. Aspanlestes sp., Parazhelestes sp. aff. P. minor, Parazhelestes sp. cf. P. robustus, and Eoungulatum sp. cf. E. kudukensis). The Aitym mammal fauna is most similar to the more diverse mammal fauna of the underlying Bissekty Formation (upper Turonian–Coniacian). Uzbekbaatar and Shalbaatar were most probably derived from North American immigrants. Paranyctoides and ‘Zhelestidae' are of Middle Asian (a commonly and long used Soviet geographic region approximately extending from the Caspian Sea on the west to the Chinese border on the east, and from the Iranian and Afghan borders on the south to southern Kazakhstan on the north) origin and migrated to North America during the late Santonian–early Campanian. A dispersal route was present in Beringia during the entire Late Cretaceous, which may have worked as a cold filter, allowing intercontinental dispersals between Asia and western North America in both directions, especially during shorter, warm climatic phases.

The role of transregional mantle-rooted structural discontinuities in the concentration of metals: With examples from the United States, China, Uzbekistan, Burma, and other countries

Transregional EW-trending mantle-rooted structural discontinuities play an important role in the concentration of metals in the northern hemisphere. Preferential concentration of metals occurs in areas where these discontinuities intersect with major structures of other trends. Previous studies focused mainly on the United States and China (Kutina, 1980b, 1983b, 1991, 1995 and 1999) are extended by the investigation of metal concentrations along westward extension of two latitudinal belts of China into neighboring parts of Asia: The transregional structural discontinuity which controls the Yinshan-Tianshan latitudinal belt of northern China and its western extension has been traced, presently, as far west as the Aral Sea region, for a distance of over 5,000 km. In western Uzbekistan the large concentrations of gold and other metals in the Central Kyzylkum Desert, including the superlarge gold deposit of Muruntau, originated at the intersection of the latitudinal belt mentioned above with a NW-trending foldbelt which is associated with the Southern Tian Shan Mountains. A major structural intersection has been defined in northern Burma at a latitude close to 24° N based on the position of seismically active fracture zones and a change in the orientation of the Wadati-Benioff Zone (using data from the seismotectonic study by Vanek et al., 1990). This intersection occurs at the latitude of a major fault of the Nanling latitudinal belt of southern China which extends towards the Burmese border and apparently continues westward. A correlation can also be seen with the latitude of the Dauki Fault in the adjoining parts of the Indian Peninsula. The position of the structural intersection mentioned above, between the major latitudinal belt of southern China and the Dauki Fault of Indian Peninsula, indicates that an old EW-trending structural discontinuity may have played a structural role in the tectonics of the younger plate interaction. The postulated structural intersection in northern Burma occurs in the Wuntho-Katha area where a volcanic belt and granitoid rocks are known as well as deposits of different metals including Zn, Cu, Au, Te, and Pt (Goossens & Myint Hla, 1977). Also, a low-temperature colloform sphalerite has been described from this area, which is characterized by the same association of typochemical elements (Ge-Tl-As) as sphalerites of the large European deposits near the German-Belgian border and in Poland (Kutina, 1969b). This area is considered to be a promising target for mineral exploration. Examples are also shown from the Czech Republic, Canada, and Australia.

Orientation study of strategic deep penetration geochemical methods in the central Kyzylkum desert terrain, Uzbekistan

Wide-spaced NAMEG (nanoscale metals in earthgas) and MOMEO (mobile forms of metals in overburden) orientation surveys were carried out in the central Kyzylkum desert terrain in the area of several giant gold deposits hosted in Paleozoic weakly metamorphosed black carbonaceous shales. The results demonstrate that gold is carried up through more than 200 m of post-ore sedimentary rocks and desert sand, and forms distinct anomalies on the surface, even with the wide-spaced sampling. The best results were obtained for Au in earthgas, and in water extractable and sorbed forms in sediment samples. The areal extent of anomalous Au values around the giant Au deposits of Muruntau, and Daughiztau is apparently more than 10,000 km 2. Newly discerned areas of Au potential occur at the south part of the shale dome. Further systematic sampling is still required for a better delineation of these anomalies.

Nanoscale metals in Earthgas and mobile forms of metals in overburden in wide-spaced regional exploration for giant deposits in overburden terrains

This paper describes the use of NAnoscale Metals in EarthGas (NAMEG) and MObile forms of MEtals in Overburden (MOMEO) methods in regional scale geochemical exploration for giant deposits in terrains covered by overburden. These methods are based on the premise that gases generated from the earth's interior can not only transport mobile forms of elements from an ore deposit and its geochemical halos to the surface to form a local anomaly, but also transport them from distinct bedrock “geochemical blocks” hosting large and giant ore deposits and give rise to large regional geochemical anomalies and geochemical provinces at the surface. Regional NAMEG and MOMEO surveys for giant gold deposits were carried out in Shandong Province, where the largest gold deposits in China are found, and in the Muruntau region of the Kyzylkum Desert, Uzbekistan, one of the world's largest gold ore provinces. In Shandong Province, where most of the area is covered by complex overburden, large regional anomalies in earthgas and water-extractable Au were delineated over and around the giant gold deposits. For many trace elements, the anomalies are larger in area and have greater contrast than those from other methods. High concentration of water soluble Au extends into the southern area covered by transported overburden, suggesting that this region may have potential for the discovery of new concealed gold deposits. The anomalous provinces of Au in both earthgas and water soluble salts coincide with a deep fault, supporting the idea that the deep fault is the main conduit of Au from the interior. In the central Kyzylkum Desert, nearly all Au-hosting rocks are covered by sedimentary sequences overlain by desert sand. Gold and As anomalies over Muruntau and Kokpatas gold deposits have contrasts ranging from 2 to 400 times background. Strong anomalies were also discovered in the south of the Muruntau region, suggesting a promising area for the discovery of new giant gold deposits.