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V. V. Sapozhnikov N. M. Zozulya S. I. Stolyarskii A. V. Azarenko D. N. Katunin 《Oceanology》2010,50(4):627-629
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V. L. Zozulya 《Water Resources》2006,33(3):329-334
Migration of biogenic substances in peats of high and low-level bogs is discussed. Experiments were carried out to determine the quantitative characteristics of the absorbing capacity of peat. A high ability of peat to absorb and hold biogenic substances was revealed. This ability depends on the degree of biogenic substance decomposition and on the amount of finely divided particles, and it is not similar in different types of biogenic substances. 相似文献
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Pyrope and Cr-diopside as indicators of mantle structure and diamond depth facies in the Kola region
PT parameters of crystallization have been determined for pyropes and Cr-diopsides from loose sediments of the Kola region, taking into account the chemical compositions of these minerals. Being either deep-seated xenocrysts or constituents of mantle xenoliths in kimberlites, pyropes and Cr-diopsides bear information on composition of the lithospheric mantle and its diamond resource potential. It was established that pyropes belong to the lherzolitic (45%), harzburgitic (30%), and eclogitic (25%) mineral assemblages. The Ni thermometry of pyropes yielded their formation temperature at 650–1250°C, which corresponds to a depth interval of 75–190 km. The distribution of different pyrope-bearing assemblages and their trace element composition allowed us to suggest a layered structure of the Kola lithospheric mantle. Its shallow unit (75–110 km) is mainly composed of depleted lherzolite; the medium-deep unit (110–170 km) consists of harzburgite, and the deep unit (170–190 km), of both lherzolite and harzburgite. About 16% of lherzolitic-harzburgitic pyropes were derived from the diamond mantle facies, i.e., from a depth of 140–190 km. Cr-diopsides are subdivided into two genetic groups: eclogitic (high Al2O3 and Na2O, low MgO and CaO) and ultramafic (high MgO, CaO, and Cr2O3; low Al2O3 and Na2O). The crystallization parameters of Cr-diopside from deep-seated ultramafic group were determined using the Cr-in-Cpx barometer and En-in-Cpx thermometer. Most samples fall into the graphite stability field (20–45 kbar and 700–1150°C). If these minerals were derived from kimberlites, this implies that the latter were constituents of carbonatite-ultramafic intrusions. Cr-diopsides may also be derived from diamond-free ultramafic xenoliths contained in alkaline ultramafic dikes. Nevertheless, 15% of Cr-diopside compositions fall in the field of diamond stability (55–60 kbar and 1000–1100°C). These conditions fit the geotherm characterizing a low heat flow. The results support the high resource potential of the Kola region for diamonds. 相似文献
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Zozulya Dmitry R. Lyalina Lyudmila M. Savchenko Yevgeny E. 《Mineralogy and Petrology》2017,111(4):511-522
Mineralogy and Petrology - The Keivy alkaline province, Kola Peninsula, NW Russia, consists of vast alkali granite massifs and several dike-like nepheline syenite bodies. It contains numerous... 相似文献
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Baotite occurs as a late phase in the Kval?ya lamproite dyke and in the fenitized granite adjacent to the dyke, suggesting that baotite formed during reactions between rock and fluids derived from a volatile-rich lamproitic magma. Most of the analyzed grains of baotite from the Kval?ya lamproite show compositions close to the ideal Nb-free end-member Ba4Ti8Si4O28Cl. Compilation of all published baotite analyses suggests that the major compositional variations of baotite occur between the Nb-free end member Ba4Ti8Si4O28Cl, and a Nb-rich end member Ba4Ti2Fe2+ 2Nb4Si4O28Cl. However, a Pb-bearing baotite, showing significant concentrations of Ca, Sr, Pb and K, and approximately 3 Ba p.f.u., was also identified from the Kval?ya lamproite. Euhedral fluorapatite formed as an early phase during crystallization of the lamproite magma, while anhedral REE-rich fluorapatite overgrowths on the euhedral grains formed during reactions with the late magmatic fluid. Fluorapatite contains up to 1.2?F p.f.u., but only traces of Cl. Other F-rich, but Cl-poor minerals of the lamproite include fluoro-potassic-magnesio-arfvedsonite, fluoro-phlogopite, and yangzhumingite. The presence of baotite together with a range of high-F, but low-Cl mineral phases suggests that the minerals formed in equilibrium with a high-F, Cl-bearing hydrous fluid. The high Cl-content of baotite demonstrates that Cl is strongly partitioned into this mineral in the presence of a Cl-bearing F-rich hydrous fluid. We suggest that a combination of high aSi, aTi, aBa, and fO2, but low aCa of the fluid enabled baotite formation. 相似文献