Evaluating the use of 3'-(p-Aminophenyl) fluorescein for determining the formation of highly reactive oxygen species in particle suspensions     

Corey A Cohn  Christopher E Pedigo  Shavonne N Hylton  Sanford R Simon  Martin AA Schoonen 《Geochemical transactions》2009,10(1):8-9

Background  

Given the importance of highly reactive oxygen species (hROS) as reactants in a wide range of biological, photochemical, and environmental systems there is an interest in detection and quantification of these species. The extreme reactivity of the hROS, which includes hydroxyl radicals, presents an analytical challenge. 3'-(p-Aminophenyl) fluorescein (APF) is a relatively new probe used for measuring hROS. Here, we further evaluate the use of APF as a method for the detection of hydroxyl radicals in particle suspensions.  相似文献   

Age of the amur group of the Bureya-Jiamusi Superterrane in the Central Asian fold belt: Sm-Nd isotope evidence   总被引：1，自引：0，他引：1  

A. B. Kotov  S. D. Velikoslavinskii  A. A. Sorokin  L. N. Kotova  A. P. Sorokin  A. M. Larin  V. P. Kovach  N. Yu. Zagornaya  A. V. Kurguzova 《Doklady Earth Sciences》2009,429(1):1245-1248

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Mesozoic age of granitoids from the Beket complex (Gonzha block within the Argun terrane of the Central-Asian Fold Belt)     

A. B. Kotov  A. A. Sorokin  E. B. Sal’nikova  A. P. Sorokin  A. M. Larin  S. D. Velikoslavinskii  T. V. Belyakov  I. V. Anisimova  S. Z. Yakovleva 《Doklady Earth Sciences》2009,429(2):1457-1461

U-Pb geochronological results confirm the Mesozoic age (124 ± 1 Ma) of the Beket granitoid complex, previously interpreted as being one of the markers amongst the Early Proterozoic magmatic complexes within the Amur superterrane (microcontinent) of the Central Asian Fold Belt. This implies that the structural and metamorphic amphibolite facies overprints documented either in the Beket granitoids or Gonzha host rocks are evidently Mesozoic rather than Early Proterozoic in age.  相似文献   

The Berezitovoe gold-polymetallic deposit (East Siberia): mineralogy,age, and relation with magmatism     

A.V. Mel’nikov  A.A. Sorokin  V.A. Ponomarchuk  A.V. Travin  A.P. Sorokin 《Russian Geology and Geophysics》2009,50(3):188-194

The Berezitovoe gold-polymetallic deposit is localized in the west of the Selenga–Stanovoi superterrane composed of a wide spectrum of Early and Late Precambrian igneous rocks and abundant Paleozoic and Mesozoic intrusive and volcanoplutonic associations. The ⁴⁰Ar/³⁹Ar ages determined for metasomatites bearing gold-polymetallic mineralization are as follows: garnet-quartz-muscovite-sericite-K-feldspathic metasomatites (129.7±3.2–127.3±4.4 Ma); muscovite-quartz-sericite metasomatites (132.0±2.9–131.3±2.3 Ma). According to the age and general scheme of evolution of the Early Cretaceous magmatism in the Selenga–Stanovoi superterrane, the metasomatites of the Berezitovoe deposit are nearly coeval to the intrusive rocks of the Amudzhikan complex (132–128 Ma). The revealed platinum potential of gold-polymetallic ores and metasomatites permits ranking the Berezitovoe deposit as a specific complex gold-polymetallic-platinum deposit, which considerably increases its commercial value.  相似文献   

Age of the Ust’-Gilyui sequence in the Stanovoi Complex of the Selenga-Stanovoi Superterrain, Central Asian fold belt     

S. D. Velikoslavinskii  A. B. Kotov  E. B. Salnikova  A. M. Larin  A. A. Sorokin  A. P. Sorokin  V. P. Kovach  E. V. Tolmacheva  S. Z. Yakovleva  I. V. Anisimova 《Doklady Earth Sciences》2012,444(2):661-665

According to the results of U-Pb geochronological investigations, the age of the amphibolite protoliths (metabasalts) in the Ust??-Gilyui sequence within the Stanovoi Complex of the Amazar-Gilyui structural and formational zone in the Selenga-Stanovoi Superterrain of the Central Asian fold belt can be estimated at 193 ± 1 Ma. The Nd model age of the Ust??-Gilyui metasedimentary rocks is in the interval of t _Nd(DM) = 1.1?C3.1 Ga. This information along with the previously obtained geochronological data are indicative of the fact that the Ust??-Gilyui sequence consists of metasedimentary and metavolcanic rocks of various ages: (1) volcanic rocks with the age of 193 ± 1 Ma; (2) metasedimentary and metavolcanic rocks broken through by the Paleozoic granitoids dated to 370 Ma and characterized by minimum estimations of t _Nd(DM) = 1.1 Ga, i.e., rocks with an age of 1.1?C0.4 Ga. In addition, it is quite possible that this sequence also includes more ancient rocks. The SSS Amazar-Gilyui structural and formational zone is likely to be a tectonic mélange composed of the metasedimentary and metavolcanic rocks of the Mesozoic and, probably, Paleozoic and Early Precambrian ages. The studied zone was formed in the Mesozoic, most likely, in the course of the collision processes initiated by the closing up of the Mongol-Okhotsk Ocean.  相似文献   

The largest recent earthquake in the Upper Amur region on October 14, 2011: First results of multidisciplinary study     

A. I. Khanchuk  D. A. Safonov  Ya. B. Radziminovich  N. S. Kovalenko  A. V. Konovalov  N. V. Shestakov  V. G. Bykov  M. A. Serov  A. A. Sorokin 《Doklady Earth Sciences》2012,445(1):916-919

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Geochemistry of paleozoic terrigenous sediments from the Oldoi terrane, eastern Central Asian orogenic belt, as an indicator of geodynamic conditions during deposition     

Yu. N. Smirnova  A. A. Sorokin  L. I. Popeko  Yu. V. Smirnov 《Geochemistry International》2013,51(4):306-325

The analysis of the major and trace element geochemistry of Paleozoic terrigenous sediments from the Oldoi terrane, eastern Central Asian orogenic belt, supports a predominantly felsic source consisting of granites and recycled sediments. The geological data suggest that detrital material could be derived from Early Paleozoic granitoids, which were identified within tectonic blocks in the Silurian and Devonian terrigenous successions. The analysis of conventional discrimination diagrams indicates that the initial stage was marked by deposition along a passive continental margin, which continued in island-arc or active continental margin environments. This interpretation is consistent with geological evidence, such as the presence of volcanic interlayers and lenses in the Middle-Late Devonian successions and granitoids with ages of 386 +/- 10 and 371+/- 5.5 Ma. The timing of changes in geodynamic settings constrained by tectonic reconstructions corresponds to the age of the inception of the Norovlya continental-margin magmatic arc.  相似文献   

Aptian bimodal volcanic associations and granitoids in the northern margin of the Amur microcontinent: Age, sources of material, and geodynamic environments     

A. A. Sorokin  A. B. Kotov  V. A. Ponomarchuk  A. P. Sorokin  V. P. Kovach  V. M. Savatenkov 《Petrology》2013,21(1):66-84

Data on the composition, age, and source of material of Aptian rocks composing a bimodal volcanic complex and related granitoids in the northern margin of the Amur microcontinent indicate that the granodiorites of the Talalinskii Massif and subalkaline granites of the Dzhiktandiunskii Massif crystallized at 117 ± 2 and 119 ± 2 Ma, respectively (⁴⁰Ar/³⁹Ar method), and their crystallization ages coincide with the age of volcanic rocks of the Gal’kinskii bimodal complex. These data make it possible to combine the rocks within a single volcano-plutonic association. Geochemical and isotopic-geochemical features of trachybasaltic andesites of the Gal’kinskii bimodal complex suggest that the parental melts were derived from such sources as PREMA (or DM) and an enriched source of the EMII type at a subordinate contribution of a crustal source. The parental melts of rhyolites of the Gal’kinskii Complex and granitoids of the Talalinskii and Dzhiktandinskii massifs were derived from crustal material with minor amounts of juvenile material. The bimodal volcanic association and related granitoids dated at 119–115 Ma were most likely formed in geodynamic environments implying the ascent of the asthenospheric mantle.  相似文献   

Late paleozoic gabbroids of the Lesser Khingan terrane of the eastern Central-Asian fold belt: Age, geochemistry, and tectonic setting     

I. V. Buchko  A. A. Sorokin  N. M. Kudryashov 《Russian Journal of Pacific Geology》2013,7(3):189-198

This paper considers the results of mineralogical, geochemical, and geochronological studies of leucogabbroids of the Karagai Massif located within the Lesser Khingan superterrane of the Central Asian fold belt. The main features of the rock-forming minerals of the gabbroids are the high calcium content of the clinopyroxene corresponding in composition to diopside-salite (Wo_48–51En_33–39Fs_11–16) or augite (Wo_22–35En_46–47Fs_18–33), the high basicity of the plagioclase (An_90–92), and the presence of primary magmatic magnesian hornblende. The age of the massif was determined by U-Pb zircon dating as 257 ± 1 Ma. The compositional peculiarities of the gabbroids indicate that they were most probably formed in island-arc or active continental margin settings. With allowance for the existing geodynamic reconstructions and the data obtained in the present study, the formation of the Late Paleozoic gabbroids of the Karagai Massif was presumably related to the final stages of the subduction processes that preceded the collapse of the terranes of the eastern Central Asian fold belt.  相似文献   

Geochemical features of felsic magmatism on the northwestern flank of the Khingan-Okhotsk volcanoplutonic belt: Ezop and Yam-Alin zones     

I. M. Derbeko  A. A. Sorokin  S. G. Agafonenko 《Russian Journal of Pacific Geology》2008,2(1):54-63

The Ezop-Yam-Alin zone was studied with emphasis on the geology, composition, and age of its felsic volcanic and intrusive rocks. All these rocks are moderately enriched in Rb (84–268 ppm), Ba (240–881 ppm), Th (10.5–17.9 ppm), and REE and depleted in Nb (5–12 ppm), Ta (0.5–1.2 ppm), and Zr (92–175 ppm). The age dates obtained by U-Pb (94.8 ± 2.2 Ma) and Rb-Sr (95.2 ± 0.69 Ma) methods for the granites of the Ezop Complex correspond to the Cenomanian.  相似文献