scholarly journals ROLE OF PYROXENITE MANTLE IN MAGMA GENESIS OF THE OLIGOCENE BASALTS FROM THE NORTHERN PART OF EAST SIKHOTE ALIN

2020 ◽  
Vol 39 (6) ◽  
pp. 82-97
Author(s):  
A.Yu. Martynov ◽  
◽  
Yu.A. Martynov ◽  
A.I. Malinovskii ◽  
◽  
...  
Keyword(s):  
Basaltic Magma ◽  
Volcanic Belt ◽  
Sikhote Alin ◽  
Late Cenozoic ◽  
Magma Genesis ◽  
First Order ◽  
Geodynamic Environment ◽  
Magma Sources ◽  
Magma Compositions

Identification of magma sources as well as its role in creating the diversity of magma compositions still remains one of the fundamental petrological problems. In our work, on the basis of new comprehensive isotope-geochemical and mineralogical data, we made an attempt to reconstruct the contribution of pyroxenite mantle source in the Oligocene basaltic magma genesis of the northern part of East Sikhote Alin volcanic belt. The most important indicators of this source are significant variations the first order transit elements ratios (Zn/Fe = 11–17, Zn/Mn = 6–10, Cr/Ni (1.8–6) and concentration of Ni (2000–3600 г/т) in olivine. LIL elements behavior suggests the presence of amphibole in pyroxenite substrate. The data obtained can be useful for the correct reconstruction of the magma generation and the geodynamic environment of this territory at the Late Cenozoic.

scholarly journals Late Cenozoic Uguumur and Bod-Uul Volcanic Centers in Northern Mongolia: Mineralogy, Geochemistry, and Magma Sources

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 612
Author(s):  
Alexander Perepelov ◽  
Mikhail Kuzmin ◽  
Svetlana Tsypukova ◽  
Yuri Shcherbakov ◽  
Sergey Dril ◽  
...  
Keyword(s):  
Basaltic Magma ◽  
Magma Source ◽  
Depth Range ◽  
Late Cenozoic ◽  
Central Mongolia ◽  
Cenozoic Volcanism ◽  
Northern Mongolia ◽  
Magma Sources ◽  
Response To Stress ◽  
Isotope Systematics

The paper presents new data on mineralogy, geochemistry, and Sr-Nd-Pb isotope systematics of Late Cenozoic eruption products of Uguumur and Bod-Uul volcanoes in the Tesiingol field of Northern Mongolia, with implications for the magma generation conditions, magma sources, and geodynamic causes of volcanism. The lavas and pyroclastics of the two volcanic centers are composed of basanite, phonotephrite, basaltic trachyandesite, and trachyandesite, which enclose spinel and garnet peridotite and garnet-bearing pyroxenite xenoliths; megacrysts of Na-sanidine, Ca-Na pyroxene, ilmenite, and almandine-grossular-pyrope garnets; and carbonate phases. The rocks are enriched in LILE and HFSE, show strongly fractioned REE spectra, and are relatively depleted in U and Th. The low contents of U and Th in Late Cenozoic volcanics from Northern and Central Mongolia represent the composition of a magma source. The presence of carbonate phases in subliquidus minerals and mantle rocks indicates that carbon-bearing fluids were important agents in metasomatism of subcontinental lithospheric mantle. The silicate-carbonate melts were apparently released from eclogitizied slabs during the Paleo-Asian and Mongol-Okhotsk subduction. The parent alkali-basaltic magma may be derived as a result from partial melting of Grt-bearing pyroxenite or eclogite-like material or carobantized peridotite. The sources of alkali-basaltic magmas from the Northern and Central Mongolia plot different isotope trends corresponding to two different provinces. The isotope signatures of megacrysts are similar to those of studied volcanic centers rocks. The P-T conditions inferred for the crystallization of pyroxene and garnet megacrysts correspond to a depth range from the Grt-Sp phase transition to the lower crust. Late Cenozoic volcanism in Northern and Central Mongolia may be a response to stress propagation and gravity instability in the mantle associated with the India-Asia collision.

Exploring Baryon Rich Matter with Heavy-Ion Collisions

2019 ◽  
Vol 64 (7) ◽  
pp. 583 ◽  
Author(s):  
S. Harabasz
Keyword(s):  
Center Of Mass ◽  
Heavy Ion ◽  
State Density ◽  
Heavy Nuclei ◽  
First Order ◽  
Center Of Mass Energy ◽  
Ion Collisions ◽  
Deconfinement Phase Transition ◽  
Ground State Density

Collisions of heavy nuclei at (ultra-)relativistic energies provide a fascinating opportunity to re-create various forms of matter in the laboratory. For a short extent of time (10-22 s), matter under extreme conditions of temperature and density can exist. In dedicated experiments, one explores the microscopic structure of strongly interacting matter and its phase diagram. In heavy-ion reactions at SIS18 collision energies, matter is substantially compressed (2–3 times ground-state density), while moderate temperatures are reached (T < 70 MeV). The conditions closely resemble those that prevail, e.g., in neutron star mergers. Matter under such conditions is currently being studied at the High Acceptance DiElecton Spectrometer (HADES). Important topics of the research program are the mechanisms of strangeness production, the emissivity of matter, and the role of baryonic resonances herein. In this contribution, we will focus on the important experimental results obtained by HADES in Au+Au collisions at 2.4 GeV center-of-mass energy. We will also present perspectives for future experiments with HADES and CBM at SIS100, where higher beam energies and intensities will allow for the studies of the first-order deconfinement phase transition and its critical endpoint.

BASALTIC MAGMA GENESIS AND MANTLE SOURCES BENEATH TWO CENOZOIC VOLCANOES, MT. EARLY AND SHERIDAN BLUFF, EAST ANTARCTICA

2020 ◽  
Author(s):  
Yuyu Li ◽  
◽  
K.S. Panter ◽  
John L. Smellie ◽  
Jerzy S. Blusztajn ◽  
...  
Keyword(s):  
Basaltic Magma ◽  
East Antarctica ◽  
Magma Genesis ◽  
Mantle Sources

scholarly journals Ganglioside incorporation and release by the isolated perfused rat liver

1991 ◽  
Vol 274 (2) ◽  
pp. 581-585 ◽  
Author(s):  
S C Kivatinitz ◽  
A Miglio ◽  
R Ghidoni
Keyword(s):  
Rat Liver ◽  
The Other ◽  
Regulatory Role ◽  
Isolated Perfused Rat Liver ◽  
Order Kinetic ◽  
Perfused Rat Liver ◽  
Ganglioside Gm1 ◽  
First Order ◽  
Pseudo First Order

The fate of exogenous ganglioside GM1 labelled in the sphingosine moiety, [Sph-3H]GM1, administered as a pulse, in the isolated perfused rat liver was investigated. When a non-recirculating protocol was employed, the amount of radioactivity in the liver and perfusates was found to be dependent on the presence of BSA in the perfusion liquid and on the time elapsed after the administration of the ganglioside. When BSA was added to the perfusion liquid, less radioactivity was found in the liver and more in the perfusate at each time tested, for up to 1 h. The recovery of radioactivity in the perfusates followed a complex course which can be described by three pseudo-first-order kinetic constants. The constants, in order of decreasing velocity, are interpreted as: (a) the dilution of the labelled GM1 by the constant influx of perfusion liquid; (b) the washing off of GM1 loosely bound to the surface of liver cells; (c) the release of gangliosides from the liver. Process (b) was found to be faster in the presence of BSA, probably owing to the ability of BSA to bind gangliosides. The [Sph-3H]GM1 in the liver underwent metabolism, leading to the appearance of products of anabolic (GD1a, GD1b) and catabolic (GM2, GM3) origin; GD1a appeared before GM2 and GM3 but, at times longer than 10 min, GM2 and GM3 showed more radioactivity than GD1a. At a given time the distribution of the radioactivity in the perfusates was quite different from that of the liver. In fact, after 60 min GD1a was the only metabolite present in any amount, the other being GM3, the quantity of which was small. This indicates that the liver is able to release newly synthesized gangliosides quite specifically. When a recirculating protocol was used, there were more catabolites and less GD1a than with the non-recirculating protocol. A possible regulatory role of ganglioside re-internalization on their own metabolism in the liver is postulated.

Late Cenozoic tectonics offshore western Mexico and its relation to the structure and volcanic activity in the western Trans-Mexican Volcanic Belt

1993 ◽  
Vol 32 (4) ◽  
pp. 543-559
Author(s):  
Hugo Delgado Granados
Keyword(s):  
Volcanic Activity ◽  
Volcanic Belt ◽  
Late Cenozoic ◽  
Western Mexico ◽  
Mexican Volcanic Belt ◽  
Cenozoic Tectonics ◽  
Trans Mexican Volcanic Belt

La tasa de convergencia calculada indica que la tectónica del occidente de México ha sido tensional durante los últimos 3 Ma. Este estilo de deformación se ve reflejado en la formación de estructuras rift en la parte occidental de la Faja Volcánica Trans-Mexicana [FVTM]. Los valores obtenidos para la tasa de convergencia predicen que, a través del tiempo, se verifica una tectónica menos tensional (con tendencia a la neutralidad) en la parte sureste de la zona de interacción de las placas de Rivera Y Norteamérica, mientras que en la parte noroccidental se vuelve más tensional. Por otra parte, un análisis cualitativo de las tasas de esparcimiento muestra que éstas fueron más rápidas antes de los 6.5 Ma de lo que fueron posteriormente. Después de analizar diferentes parámetros cinemáticos, se concluyó que la tasa de esparcimiento de la cresta del Pacífico Oriental en su sector Pacífico-Rivera, influye fuertemente sobre la tasa de convergencia. De esta manera se puede establecer una correlación positiva entre la evolución de la tasa de esparcimiento de la cresta Pacífico-Rivera y la geología continental. Esta correlación muestra que tasas de esparcimiento relativamente rápidas coinciden con la presencia de volcanismo monogenético calci-alcalino en la parte occidental de la FVTM cuando menos desde hace 10 Ma y que este tipo de volcanismo continúa hasta nuestros días. Sin embargo, cuando la tasa de esparcimiento se ha hecho más lenta (y por tanto la tasa de convergencia se ha hecho menor) durante el periodo comprendido entre 6.5 Ma y 3.5 Ma, se ha verificado en la región una tectónica extensional ampliamente distribuida, volcanismo explosivo y sedimentación lacustre en los sistemas rift de Colima, Tepic-Zacoalco y de Chapala; particularmente entre los 4.6 Ma y 3.9 Ma ha coincidido con volcanismo alcalino en los rifts fr Colima y Tepic-Zacoalco. Un leve incremento en la tasa de esparcimiento después de los 3.5 Ma coinciden con el decremento de actividad volcánica (principalmente alcalina). Durante el periodo entre 1.6 Ma y 0.7 Ma, la tasa de esparcimiento disminuyó de nuevo coincidiendo con un fallamiento normal continuo en las tres estructuras rift mencionadas y en parte, con otra etapa de volcanismo alcalino (entre 1.4 Ma y 0.2 Ma) en los rift de Colima y Tepic-Zacoalco. Después de los 0.7 Ma, la tasa de esparcimiento se ha incrementado levemente. Por otra parte, se observa una relación genética entre el contenido de elementos compatibles en rocas volcánicas de la región con la tasa de convergencia, lo cual implica que tasas de subducción mayores aportan una mayor cantidad de sedimentos acrecionados a la cuña del manto. Esto explica las diferencias geoquímicas entre las rocas volcánicas a lo largo del frente volcánico de la parte occidental de la FVTM.

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