Journal/NDM57 2023 eng
New Data on Minerals, Volume 57, 2023
DEADLINES FOR ARTICLES
Issue 1 - March 31, 2023
Issue 2 - May 31, 2023
Issue 3 - August 31, 2023
Issue 4 - November 30, 2023
Editorial Board
Editor in Chief:
Plechov P.Yu. -D.Sc. in Geology and Mineralogy, Professor
Members of Editorial Board:
Pekov I.V. - Corresponding Member of the Russian Academy of Sciences
Garanin V.K. - D.Sc. in Geology and Mineralogy, Professor
Borutsky B.E. - D.Sc. in Geology and Mineralogy
Spiridonov B.E. - D.Sc. in Geology and Mineralogy
Chukanov N.V. - D.Sc. in Physical and Mathematical Sciences
Kamenetsky V.S. - Professor (University of Tasmania)
Nenasheva S.N. - PhD in Geology and Mineralogy
Matvienko E.N. - PhD in Geology and Mineralogy
Generalov M.E. - PhD in Geology and Mineralogy
Pautov L.A. - Senior Researcher
Layout Designer
Kronrod E.V. - PhD in Chemistry
Content
Issue 1
Plechov P. Yu., Ushakova S.A., Shcherbakov V.D.
Mineralogy and Genesis of Karites of the Murun Complex, p. 5-13
We studied mineralogy of the karite sample from Murun alkaline complex. Karite belongs to the silexites group and has so far been one of the few rocks of this family whose igneous genesis has not been questioned. The studied rock consists of quartz (73 vol. %), aegirine (4 vol. %), orthoclase (23 vol. %), and a number of accessory minerals, which are typical for fenites (narsarsukite, steacyite-turkestanite, delyite, etc.). Large euhedral quartz crystals with numerous oriented aegirine ingrowths create a formal resemblance to the porphyritic texture of effusive rocks, however, formation conditions of rock-forming minerals correspond to low temperature (<400℃). Possibly the rock was formed during the impregnation of a silica-rich fluid through a grorudite or aegirinite substrate. The study of karite of the Murun complex did not reveal any sign of the igneous genesis of these rocks. It can be concluded that karites, like many other representatives of the silexites family, are not magmatic, but of hydrothermal-metasomatic origin.
Keywords: Murun alkaline complex, silexites, quartz, steaciite, turkestanite, narsarsukite. читать далее...
Электронные приложения к статье : Plechov2023_Suppl.xlsx
Rumyantseva N.А., Berezin А.V., Vanshtein B.G., Skublov S.G.
Clinopyroxene composition as an indicator of the conditions of crystallization of gabbroids from the Shaka Ridge (South Atlantic), p. 14-13
The paper presents the results of geochemical research (major, trace and rare earth elements) for clinopyroxene grains extracted from gabbro-type rocks of the Shaka Ridge, South Atlantic. The clinopyroxene belongs to the Ca–Mg–Fe type and is characterized by a smooth change in chemical composition from the center to the edge of the grains, expressed in a decrease in the magnesia value of Mg#, an increase in the total REE concentration and a more distinct manifestation of the negative Eu-anomaly. Based on the geochemical and morphological features of the grains, it is concluded that fractional crystallization significantly affects the composition of clinopyroxene during its formation. The estimation of P-T parameters by several methods allowed us to designate a narrow range of temperatures (1225–970 °C) and pressures (3–1 kbar) at which clinopyroxene crystallized.
Keywords: clinopyroxene, geochemistry, trace elements, REE, Shaka Ridge, South Atlantic. читать далее...
