Experimental modeling of subsolidus parageneses of ultramafic lamprophyres of the Irkeneeva-Chadobets trough, South -Western Siberia, at high PT-parametersстатья
Дата последнего поиска статьи во внешних источниках: 1 апреля 2020 г.
Аннотация:Paper presents the results of experiments on Devonian ultramafic lamprophyres from the Ilbokich uplift, Erkeneeva-Chadobetskaya trough, South-Western margin of the Siberian craton (Kargin et al., 2016). The studied rocks characterize the diversity and complexity of the Devonian alkaline magmatism of the region, they are manifested in the form of a series of low-power (5-100 cm) dikes, which were found in the core of the well at the Ilbokich Gas-condensate field. The experiments were carried out on the "anvil with a hole" type installation NL-13T in IEM RAS at pressures of 4 and 5 GPa and temperatures of 1100 -15000C. The results of the experiments showed that at a pressure of 5 GPa, paragenesis is obtained, which differs from the natural association of minerals: in the experiments, the appearance of clinohumite is observed, there is no olivine in the products of experiments conducted at temperatures below 15000C. At 4 GPa there is a mineral paragenesis similar to the natural one: mica-olivine-pyroxene rock with carbonate minerals in the bulk. In all experiments, the paragenesis and composition of minerals are identical, the only difference is in their ratio. Thus, the composition of paragenetic minerals obtained by melting natural aillikitesat 4 GPa is more consistent with the paragenesis of natural samples, which may indicate P-T parameters of formation of natural Siberian aillikitesunder identical thermodynamic conditions.Keywords: aillikites, alkaline-ultramafic lamprophyres, high-pressure experiment, experimental geochemistry, aillikites paragenesis, Chadobets uplift, Ilbokich uplift, Siberian craton
