743 resultados para Fraction


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An additional ore field in the central part of the MARhas been discovered. Together with previously discovered Logachev (14°45'N) and Ashadze (12°58'N) ore fields, the new ore field constitutes a cluster with preliminarily estimated total ore reserve of >10 Mt, which is comparable with large continental massive sulfide deposits.

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Results of investigations of Baikal bottom sediments from a long core (BDP-97) and several short (0-1 m) cores are presented. It can be shown that Holocene sediments in the Baikal basins consist of biogenic-terrigenous muds accumulated under still sedimentation conditions, and of turbidites formed during catastrophic events. The turbidites can be distinguished from the host sediments by their enrichment in heavy minerals and thus their high magnetic susceptibility. Often, Pliocene and Pleistocene diatom species observed in the Holocene sediments (mainly in the turbidites) point to redeposition of ancient offshore sediments. Our results indicate that deltas, littoral zones, and continental slopes are source areas of turbidites. The fact that the turbidites occur far from their sources confirms existence of high-energy turbidity currents responsible for long-distance lateral-sediment transport to the deep basins of the lake.