An unusual variety of geophagy – snow sheep coal consumption in the Transbaikalian mountains

Several places were discovered in the mountains of the Kodar ridge in Transbaikalia, that are regularly visited by bighorn sheep (Ovis Nivicola) for the purpose of consuming coal (Chepinskaya Formation, Jurassic). According to observations an adult ram eats from tens to hundreds of grams of coal gruss and dust at once. A comprehensive study of “eatable” coals was carried out, including their geochemistry with determination of the content and balance of mobile forms of microelements, including rare earth elements (REE). It has been established that the sum of REE in coal varies from 0.19 to 0.27 kg/t, which is 3.5–4 times higher than the clarke value. The REE composition is dominated by elements of the light subgroup (LREE). The presence of monazite, xenotime and rhabdophane in the consumed coals was established by analytical scanning electron microscopy. An acid (HCl, pH-1) extract from minerals showed, that among the elements released from coal, only some microelements, including LREEs, are most likely to be of greatest importance for animals. The data obtained, considering our previously conducted landscape-geochemical studies of mass geophagy areas in the Sikhote-Alin, the Gorny Altai and on the island. Olkhon (Baikal), suggest that the reason for the regular consumption of coals by bighorn sheep on the Kodar Ridge is due to the animals intention to restore the disturbed balance of REE in the body.