3 research outputs found
The results of detection of thyzaniezia in reindeer from baruun taiga
The reindeer Rangifer tarandus Linnaeus, 1758, is a local animal (west) taiga in Tsagaannuur soum of Khuvsgul aimag. The species, one of semi-domesticated populations, is well adapted to harsh climate as like as tundra and sub tundra areas. The reindeer was slaughtered by herdsmen for their own food consumption and the post-mortem examination was done by incomplete methods of necropsy (Skrybini, 1945). It is a first time detection to find for Thysaniezia spp. tapeworm in reindeer from Mongolia. In the future we will expand the study of parasitic and infectious diseases of the reindeer.
Баруун тайгын цаа буганд thyzaniezia төрлийн туузан хорхой илрүүлсэн дүн
Хураангуй: Хөвсгөл аймгийн Цагааннуур сумын Баруун тайгад Rangifer tarandus, Linnaeus, 1758 зүйлийн цаа буга (буган цаа) өргөн тархжээ. Цаа буга нь тундр, тундр орчмын бүсийн эрс тэс уур амьсгалд дасан зохицсон хагас гэршсэн хөхтөн юм. Дээрх бүс нутгаас хүнсний хэрэгцээнд нядласан цаа буганд цагаан хорхойн судлалын бүрэн бус задлан шинжилгээг хийв. Манай оронд маллагдаж буй цаа буганаас анх тутам Thysaniezia төрлийн туузан хорхойг илрүүлэв. Цаашид цаа бугын зүй бус хорогдлын үндсэн шалтгаан паразиттах, халдварт, халдваргүй өвчний судалгааг өргөжүүлэх чухал шаардлагатай.
Түлхүүр үг: Нарийн гэдэс, задлан шинжилгээ, Rangifer tarandus, баасны дээж, хавтгай хорхо
Cenozoic volcanism on the Hangai Dome, Central Mongolia: geochemical evidence for changing melt sources and implications for mechanisms of melting
Cenozoic volcanism within Mongolia forms part of a large central Asian province of intra-plate magmatism. Numerous small-volume volcanic cones and alkali basalt lava flows have been formed since c. 30 Ma; from c. 12 Ma activity has been focused on the uplifted Hangai dome. A mechanism for melting beneath the dome has, however, thus far remained enigmatic. Some of the oldest basalts on the Hangai dome erupted at its centre at ∼6 Ma and their geochemistry suggests a garnet lherzolite source region at 90–100 km depth. These lavas have Pb isotope compositions similar to those of depleted Indian mid-ocean ridge basalts (MORB) (206Pb/204Pb = 17·822, 207Pb/204Pb = 15·482, 208Pb/204Pb = 37·767), which may be indicative of the involvement of ambient asthenospheric mantle in their petrogenesis. Younger basalts exhibit a gradual shift in isotopic composition towards a source that has less radiogenic Pb and more radiogenic Sr, evidenced by the eruption of lavas with 206Pb/204Pb = 16·991 and 87Sr/86Sr = 0·704704. The youngest lavas, dated as younger than ∼8 ka, have the highest K2O contents (up to 5·2 wt %) and are characterized by the most enriched trace-element signatures; they are interpreted to represent melting of a metasomatically altered sub-continental lithospheric mantle containing phlogopite. Concurrent with progressive melting of the lithosphere, melting appears to propagate outwards from the centre of the dome to its margins; by 0·7 Ma the marginal magmatism is interpreted to result from melting of a depleted MORB-source mantle component with a smaller contribution from the lithospheric mantle. The spatial and temporal variations in melting beneath the Hangai dome may be explained by either lithospheric delamination or the presence of a small-scale thermal anomaly in the upper mantle. Although it is not possible to distinguish between these models on the basis of geochemistry alone, the lack of a viable mechanism to generate small-scale upwelling lends support to a model involving delamination of the lithospheric mantle beneath the Hangai dome