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1.
Pertsev A. N. Bortnikov N. S. Prokofiev V. Yu. Aranovich L. Ya. Ageeva O. A. Beltenev V. E. Zhilicheva O. M. Kovalchuk E. V. 《Doklady Earth Sciences》2018,480(1):661-665
New data on local mineral associations and the microheterogeneity of minerals and fluid inclusions in gabbro were obtained for the gabbro–peridotite oceanic core complex with a long-lived detachment fault controlling the hydrothermal activity. It is assumed that the hydrothermal hydrogen-bearing fluid with a NaCl content of >30 wt % is formed in the seawater/harzburgite (~1/5) reaction of serpentinization. The brine residual after serpentinization interacted with gabbro at the final stages of crystallization of an intrusion and assimilated some components (K, REEs, and Ba) from the residual melt. The interaction was resulted in metamorphic transformations of gabbro at decreasing temperature below 500°C. The reaction of the decomposition of magmatic titanomagnetite with the transition of iron reduced to Fe2+ into newly formed chlorinebearing amphibole at 540–450°C and logf(O2) from–20 to–24 is shown.
相似文献2.
Regularities in variations in the intensity of hydroxyl radiation (the (6–2) λ834.4-nm band) and the Atmospheric system of molecular oxygen (the A(0–1) λ864.5-nm band) of the mesopause, hydroxyl temperature, and its night variability during sudden winter warmings of the stratosphere have been obtained based on long-term observations in Zvenigorod. 相似文献
3.
A. N. Pertsev N. S. Bortnikov E. A. Vlasov V. E. Beltenev I. G. Dobretsova O. A. Ageeva 《Geology of Ore Deposits》2012,54(5):334-346
The oceanic core complexes and large-offset detachment faults characteristic of the slow-spreading Mid-Atlantic Ridge are crucial for the structural control of large hydrothermal systems, including those forming sub-seafloor polymetallic sulfide mineralization. The structural-geological, petrographic, and mineralogical data are considered for the oceanic core complex enclosing the Semenov-1, -2, -3, -4, and -5 inactive hydrothermal sulfide fields recently discovered on the Mid-Oceanic Ridge at 13°31?? N. The oceanic core complex is composed of serpentinized and talc-replaced peridotites and sporadic gabbroic rocks, however, all hydrothermal fields reveal compositional indications of basaltic substrate. The volcanic structures superposed on the oceanic core complex are marked by outcrops of pillow lavas with fresh quenched glass. Dolerites regarded as volcanic conduits seem to represent separate dike swarms. The superposed volcanic structures develop largely along the near-latitudinal high-angle tectonic zone controlling the Semenov-1, -2, -5, and -3 hydrothermal sulfide fields. The manifestations of hydrothermal metasomatic alteration are diverse. The widespread talcose rocks with pyrrhotite-pyrite mineralization after serpentinite, as well as finding of talc-chlorite metabasalt are interpreted as products of hydrothermal activity in the permeable zone of detachment fault. Chloritization and brecciation of basalts with superposed quartz or opal, barite, and pyrite or chalcopyrite mineralization directly related to the sub-seafloor sulfide deposition. The native copper mineralization in almost unaltered basalts at the Semenov-4 field is suggested to precipitate from ore-forming fluids before they reach the level of sub-seafloor sulfide deposition. Amphibolites with plagiogranite veinlets are interpreted as tectonic fragments of the highest-temperature portions of hydrothermal systems, where partial melting of basic rocks in the presence of aqueous fluid with formation of plagiogranitic melt is possible. Silicic rocks (plagiogranite, tonalite and diorite) revealed in the tectonic zone controlling the Semenov-1, -2, -5, and -3 hydrothermal sulfide fields are related to both plutonic and subvolcanic bodies and considered to be products of partial melting of basic rocks at deep levels of the hydrothermal systems. The hydrothermal fields differ in their structural position. The giant Semenov-4 field is located at the area where the hanging-wall basalt wedges out and the detachment fault zone reaches the oceanic floor. The range of relatively small Semenov-1, -2, -3, and 5 fields develops on the oceanic core complex massif, being localized in the superposed volcanic structures within the near-latitudinal steeply dipping tectonic zone. The structural control of the hydrothermal fields at 13°31?? N is also interpreted in different ways. For the Semenov-4 field, the ascending fluid flow can be related to the permeable detachment fault zone. The root zone of the hydrothermal system with a magmatic heater could have been localized at a significant distance beneath the axial spreading zone. For the other four relatively small fields, it is suggested that the ascending fluid flows and roots of the hydrothermal systems are controlled by the volcanic structures superposed on the oceanic ore complex within the steeply dipping tectonic zone. 相似文献
4.
A. E. Zadov I. V. Pekov N. V. Zubkova V. M. Gazeev N. V. Chukanov V. O. Yapaskurt P. M. Kartasheov E. V. Galuskin I. O. Galuskina N. N. Pertsev A. G. Gurbanov D. Yu. Pushcharovsky 《Geology of Ore Deposits》2013,55(7):541-548
A new mineral aklimaite, Ca4[Si2O5(OH)2](OH)4 · 5H2O, has been found near Mount Lakargi, Upper Chegem caldera, Kabardino-Balkaria, the Northern Caucasus, Russia, in the skarnified limestone xenolith in ignimbrite. This hydrothermal mineral occurs in a cavity of altered larnite skarn and is associated with larnite, calcium humite-group members, hydrogarnets, bultfonteinite, afwillite, and ettringite. Aklimaite forms transparent, colorless (or occasionally with pinkish tint) columnar or lath-shaped crystals up 3 × 0.1 × 0.01 mm in size, flattened on {001} and elongated along {010}; they are combined in spherulites. The luster is vitreous; the cleavage parallel to the {001} is perfect. D calc = 2.274 g/cm3. The Mohs’ hardness is 3–4. Aklimaite is optically biaxial, negative, 2V meas > 70°, 2V calc = 78°, α = 1.548(2), β = 1.551(3), γ = 1.553(2). The IR and Raman spectra are given. The chemical composition (wt %, electron microprobe) is as follows: 0.06 Na2O, 0.02 K2O, 45.39 CaO, 0.01 MnO, 0.02 FeO, 24.23 SiO2, 0.04 SO3, 3.22 F, 27.40 H2O(calc.), ?1.36 -O=F2; the total is 99.03. The empirical formula calculated on the basis of 2Si apfu with O + OH + F = 16 is as follows: (Ca4.02Na0.01)Σ4.03[Si2.00O5.07(OH)1.93][(OH)3.16F0.84] Σ4.00 · 5H2O. The mineral is monoclinic, space group C2/m, a = 16.907(5), b = 3.6528(8), c = 13.068(4) Å, β = 117.25(4)·, V= 717.5(4) Å3, Z = 2. Aklimaite is representative of the new structural type, the sorosilicate with disilicate groups [Si2O5(OH)2]. The strongest reflections in the X-ray powder patterns [d, Å (hkl)] are: 11.64(100)(001), 2.948(32)(310, 203), 3.073(20) ( $\bar 404$ , $\bar 311$ ), 2.320(12)(005, 510), 2.901 (11)(004), 8.30(10) $\left( {\bar 201} \right)$ . The type specimen is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow. 相似文献
5.
The seasonal dependences of the response of the hydroxyl ((6–2) band) and molecular oxygen O2(b 1Σ g + ) ((0–1) band) emission intensities, temperature, and density indicator in the region of the hydroxyl emission maximum (87 km) to solar activity have been obtained based on the spectral observations of the mesopause emissions at Zvenigorod observatory during 2000–2007. The ratio of the OH (7–3) and (9–4) band intensities, characterizing the behavior of the vibrational temperature, has been used as an indicator of density. It has been established that the response of the studied mesopause characteristics to solar activity is positive in all seasons. In winter the response is maximal in the intensities and temperature and is minimal in the density indicator. The main mechanisms by which solar activity affects the mesopause characteristics have been considered. The behavior of the internal gravity waves with periods of 0.33–7 h depending on solar activity has been studied. It has been noted that these waves become more active at a minimum of the 11-year solar cycle. 相似文献
6.
V. V. Reverdatto N. N. Pertsev V. N. Korolyuk 《Contributions to Mineralogy and Petrology》1979,70(2):203-208
The article describes the thermal metamorphism of siliceous carbonate rocks near the dolerite intrusive body in Eastern Siberia. The mineral associations at the immediate contact with dolerite are the following: wollastonite+rankinite, rankinite+spurrite (+melilite?), spurrite+melilite+merwinite+calcite and merwinite+monticellite+melilite+calcite. The melilite in these associations is usually unzoned; its composition being essentially gehlenitic. During the regressive stage of contact metamorphism new akermanite-rich melilite and calcite were formed by replacement of merwinite and earlier gehlenitic melilite through participation of CO2. The newly forming melilite grains have sharp compositional zoning. The origin of zoning was connected with the fall of temperature and decrease of the mole fraction of CO2 in the fluid equilibrated with the minerals. 相似文献
7.
Edward S. Grew Nikolai N. Pertsev Stanislav Vrána Martin G. Yates Charles K. Shearer Michael Wiedenbeck 《Contributions to Mineralogy and Petrology》1998,131(1):22-38
Kornerupine, (□,Fe,Mg)(Mg,Fe,Al)9(Si,Al,B)5 (O,OH,F)22, has been reported with talc in rocks from six localities worldwide, but only at Chilapila Hill in the Lufilian Arc, Zambia
do textural relationships imply that kornerupine (Krn) equilibrated with talc (Tlc) during a prograde metamorphic event at
T≈ 640 °C, P≈ 13 kbar; a prograde Krn + Tlc assemblage has also been reported from Mautia Hill, Tanzania (P ≤ 13 kbar). In order to estimate possible constraints on the stability range for the kornerupine + talc paragenesis in nature,
we constructed a P-T diagram in the model system MgO-Al2O3-SiO2-H2O (MASH) for seven phases quartz (Qtz), B-free kornerupine sensu stricto, anthophyllite (Ath), chlorite (Chl), cordierite
(Crd), kyanite (Ky), and talc. The minimum pressure for Krn + Tlc + Ky stability in MASH is close to that for Ky + Tlc stability,
i.e., 6–8 kbar, at T≤ 780 °C. However, in the natural system, B2O3 and Na2O are major constituents in Krn and orthoamphibole (Oam), respectively, and dravitic tourmaline (Tur) is widespread. The critical
assemblage alternative to Krn + Tlc in nature is Tur + Oam. The upper pressure limit of Tur + Ath is determined by the upper
pressure for anthophyllite: 7.7–10.5 kbar at 682–794 °C in the MgO-SiO2-H2O system (Chernosky et al. 1985, Am Mineral 70:223–236), and is undoubtedly higher in the presence of Na2O, CaO, and Al2O3. At three of the six localities, talc is a retrograde phase; nonetheless, it possibly equilibrated with kornerupine on the
retrograde path or during a later metamorphic event at P-T conditions appropriate for Ky + Tlc. At the sixth locality (Mulvoj, southwestern Pamir Mountains, Tajikistan), Krn is found
in the same thin section as talc and kyanite and all three minerals formed during a prograde metamorphic event at T≥ 650 °C, P near 7 kbar. However, Krn is restricted to a lens 4 to 6 mm thick of phlogopite + anthophyllite + Tur and it does not touch
either talc or kyanite. A reaction relating the Mulvoj and Chilapila Hill (Krn + Tlc + Ky + Qtz + Tur) parageneses is calculated
from compositions in the Mulvoj rock to be 0.40Tur + 2.55Ath + 1.33H2O + 0.27F = Krn + 2.16Tlc + 0.36B2O3 + 0.02Rutile + 0.19Na2O + 0.17CaO. Given the difference in metamorphic pressures estimated for Mulvoj and Chilapila Hill, Krn + Tlc is inferred
to be favored by increasing pressure as well as by low Na2O and CaO contents. Some FeO, F, Fe2O3, and BeO are present in measurable amounts in at least one of the phases in the Mulvoj and Chilapila Hill whiteschists (e.g.,
Krn contains 0.24–0.67 wt% BeO), but the effect of these constituents is subordinate to that of Na2O, CaO and B2O3. The Krn + Tlc could be a more important assemblage in B-bearing whiteschists than has been reported to date, particularly
at pressures where orthoamphibole is no longer stable.
Received: 21 April 1997 / Accepted: 13 October 1997 相似文献
8.
Genetic types of diamond mineralization 总被引：1，自引：0，他引：1
A. A. Marakushev Sang Longkang You Zhendong I. A. Zotov N. N. Pertsev N. A. Paneyakh 《中国地球化学学报》1998,17(1):12-28
The paper describes the proposed models of diamond formation both in meteorites and in kimberlite and lamproite bodies, metamorphic
complexes and explosive-ring structures (“astroblemes”). The diamond distribution in meteorites (chondrites, iron meteorites
and ureilites) is restricted to taenite-kamasite phase. The diamond generation here is tied up with the first stage of evolution
of the planets. This stage is characterized by high pressure of hydrogen, leading to the formation of the planet envelope.
The second stage of planet evolution began with the progressive impoverishment of their atmospheres in hydrogen due to its
predominant emission into the space and to progressive development of oxidative conditions. The model appears to have proved
the relict nature of diamond mineralization in meteorites.
Diamond and other high-pressure minerals (its “satellites”) were crystallized without any exception in the early intratelluric
stages of peridotite and eclogite-pyroxenite magma evolution just before the magma intrusion into the higher levels of the
mantle and crust where diamond is not thermodynamically stable. The ultramafic intrusive bodies (bearing rich relict diamonds)
in the base of a platform appear to be the substrata for the formation of kimberlite-lamproite magma chambers as a result
of magmatic replacement. The model explains the polyfacial nature of diamondiferous eclogites, pyroxenites and peridotites
and discusses the process of inheritance of their diamond mineralization by kimberlites and lamproites.
Diamond productivity of metamorphic complexes is originated by the inheritance of their diamonds from the above-mentioned
primary diamondiferous rocks. Large diamondiferous explosive-ring structures were formed by high-energy endogenic explosions
of fluid which came from the Earth’s core. This high energy differs endogenic impactogenesis from explosive volcanism. It
proceeds at very high temperature to create diaplectic glasses (monomineral pseudomorphs) —the product of isochoric melting,
at the pressure high enough for the stable formation of very high-density minerals (coesite, stishovite, diamond, lonsdaleit,
and chaoite).
The research project was financially supported by the Russian Foundation of Fundamental Sciences (93-05-8566, 96-05-64307,
and 96-05-00026c0) and China National Natural Science Foundation (No.49794041, No.49611121831). 相似文献
9.
B. P. Pertsev 《Izvestiya Physics of the Solid Earth》2007,43(7):547-553
Methods taking into account the effect of tidal forces on gravity measurements are considered. Corrections for the effect of tidal forces can exceed 250 μGal. Only the structure of the Earth and positions of tide-generating celestial bodies are necessary for taking into account earth tides, while cotidal charts are additionally required for the correct incorporation of the effect of ocean tides. The effect can reach a few tens of μGal near shorelines. The modern accuracy of gravity measurements being 1–2 μGal, the ocean tide effect, together with other less significant factors, should be considered for the correct interpretation of gravity data. 相似文献
10.