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201.
Quantification of geodiversity and its loss 总被引:1,自引:0,他引:1
Dmitry A. Ruban 《Proceedings of the Geologists' Association. Geologists' Association》2010,121(3):326-333
Geodiversity, i.e., a diversity of geological heritage sites, can be quantified with an account of geosite types, type counterparts, and their ranks. Higher numbers of geosite types represented within a given territory and their higher ranks indicate a higher geodiversity. Two additional characteristics, namely geoabundance and georichness, allow measure of the quantity of geosites and the diversity-quantity relationship respectively. Geodiversity loss can be evaluated with an accounting of decreases in geosite type ranks linked to the damage of geosites. A calculation of relative and multi-dimensional geodiversity helps in quantitative assessment of the regional geological heritage. 相似文献
202.
Christoph Breitkreuz Hassan Eliwa Ibrahim Khalaf Khaled El Gameel Benjamin Bühler Sergei Sergeev Alexander Larionov Mamoru Murata 《Precambrian Research》2010
Chronology of Neoproterozoic volcanosedimentary successions remains controversial for many regions of the Arabian–Nubian Shield, including the Dokhan Volcanics of NE Egypt. New U–Pb zircon SHRIMP ages have been obtained for 10 silica-rich ignimbrites and two subvolcanic dacitic bodies, mapped as Dokhan Volcanics, from the North Eastern Desert of Egypt. Crystallization ages range between 592 ± 5 and 630 ± 6 Ma (Early Ediacaran). Apparently, the late consolidation of the Arabian–Nubian Shield was accompanied by the evolution of isolated volcanic centres and basin systems which developed during a period of approx. 40 Ma, independently in space and time and probably under changing tectonic regimes. The obtained age data together with other previously published reliable ages for Dokhan Volcanics suggest two main pulses of volcanic activity: 630–623 Ma and 618–592 Ma. Five samples contain inherited zircons, with ages of 669, 715–746, 847 and 1530 Ma, supporting models that North Eastern Desert crust is mainly juvenile Neoproterozoic crust. 相似文献
203.
Dmitry D. BADJUKOV Franz BRANDSTÄTTER Jouko RAITALA Gero KURAT 《Meteoritics & planetary science》2010,45(9):1502-1512
Abstract– A large number of micrometeorites (MMs) was recovered from glacier deposits located at the north‐eastern passive margin of the Novaya Zemlya glacier sheet. Melted, scoriaceous, and unmelted micrometeorites (UMMs) are present. Unmelted micrometeorites are dominated mostly by chondritic matter, but also a few achondritic MMs are present. Here we report the discovery of four UMMs that, according to their texture, mineralogy, and chemistry, are identified as basaltic breccias. Mineral chemistry and Fe/Mn ratios of two basaltic micrometeorites indicate a possible relationship with eucrites and/or mesosiderites, whereas two others seem to have parents, which appear not to be present in our meteorite collections. The basaltic breccia UMMs constitute 0.5% of the total population of the Novaya Zemlya MM suite. This content should be lowered to 0.25% because the Novaya Zemlya MM collection appears to be biased with carbonaceous UMMs being underrepresented. 相似文献
204.
A. S. Kharin V. N. Andruk S. Bartasiute G. Z. Butenko I. P. Vedenicheva A. V. Perekhod A. V. Sergeev 《Kinematics and Physics of Celestial Bodies》2007,23(4):147-156
Five sky areas about the radio sources ICRS 1254+571, ICRS 1345+125, ICRS 1641+399, ICRS 1732+389, and ICRS 1807+698 were observed with the aim to identify reliably the extragalactic radio sources in these areas with bright infrared objects and objects in the optical range. The test CCD observations were made in the U, V, and R bands of the Johnson system with the 2-meter telescope of the Terskol Peak Observatory (North Caucasus, Russian Federation). The U, V, and B magnitudes and the equatorial coordinates α and δ in the USNO-A2.0 catalog system were determined for objects down to V ≈ 23m in 8.5′ × 8.5′ areas, and these objects were identified with stars and infrared objects in the 2MASS catalog. The CCD image processing realized within the MIDAS/ROMAFOT program package on the basis of a new method for flat-field elimination is briefly described. 相似文献
205.
206.
S. B. Lobach-Zhuchenko E. V. Bibikova V. V. Balagansky S. A. Sergeev G. V. Artemenko N. A. Arestova N. P. Shcherbak S. L. Presnyakov 《Doklady Earth Sciences》2010,433(1):873-878
The novel detailed geological and geochronological data for the tonalitie rocks and products of its structural and metamorphic
overprint in the Orekhovo-Pavlogradskaya collision zone (Ukrainian Shield) are discussed. Magmatic crystallization of tonalites
(3500 ± 13 Ma) followed by amphibolite (2863 ± 22 Ma) and granulite (2105 ± 40 Ma) facies metamorphic events, resulting in
biotite-garnet gneisses formation. The last date also indicating the time of collision event. The earliest age of 3.64 Ga
was found in the zonal zircon fragment within 3.5-Ga old magmatic zircon from tonalite. 相似文献
207.
208.
D.P. Gladkochub T.V. Donskaya V.S. Fedorovsky A.M. Mazukabzov A.N. Larionov S.A. Sergeev 《Russian Geology and Geophysics》2010,51(5):447-460
We report data from the Khadarta, Khoboi, and Orso metamorphic complexes of the Olkhon terrane in the western Baikal region. High-grade rocks in the three complexes may have been derived from active continental margin rocks (island arc–backarc basin system). The backarc basin history possibly began at 840–800 Ma, according to SHRIMP-II U-Pb zircon ages of the Orso gneiss. Many tectonic units in the Olkhon terrane belonged to the active margin of the Barguzin microcontinent which rifted off the Aldan province of the Siberian craton in the early Neoproterozoic. The accretion of the microcontinent to the craton was accompanied by high-grade metamorphism recorded in the Khadarta and Khoboi granulites. The 507 ± 8 Ma and 498 ± 7 Ma SHRIMP-II U-Pb zircon ages of the latter complexes, respectively, may refer to the earliest evolution stage of the Olkhon metamorphic terrane. New data for the Olkhon terrane agree well with the ages of other high-grade complexes along the southern Siberian craton (Slyudyanka, Kitoikin, Derba) and correspond to the initiation of the Central Asian orogen. With these data, the Olkhon metamorphic terrane has been interpreted as an Early Paleozoic collisional collage of fragments of the microcontinent’s Neoproterozoic active margin. 相似文献
209.
K. P. Tsvetkova M. K. Tsvetkov T. P. Sergeeva A. V. Sergeev 《Kinematics and Physics of Celestial Bodies》2009,25(5):269-276
The latest version of the Wide-Field Plate Database Catalogue of Wide-Field Plate Archives (April 2008) contains 43 archives
stored at some Ukrainian observatories, namely, at the Main Astronomical Observatory of the National Academy of Sciences of
Ukraine (Golosiiv, Kyiv), at the Crimean Astrophysical Observatory (Nauchnyi and Simeiz), at the Kyiv, L’viv, and Odesa University
Observatories, and at the Mykolaiv Observatory. About 126000 plates were obtained from 1898 to 2005 in the framework of the
following observing programmes: Solar System Bodies Observations, Observations of Variable Stars, Investigations of the Emission
Nebulae and Connected Stars, Spectral Classification of the Stars and Determination of the Stellar Absorption in the Direction
of the Emission Nebulae, Photographic Survey of the Northern Sky (FON), Investigation of the Kinematics and Structure of the
Main Meridian Section of our Galaxy (MEGA), Observation of Selected Reference Stars, Artificial Satellites Observations and
other. At the moment the basic information on 12609 plates from 13 plate archives of the Main Astronomical Observatory and
Crimean Astrophysical Observatory is included into the Wide-Field Plate Database Catalogue of Wide-Field Plate Indexes (Sofia,
Bulgaria). The plate digitization is just started with flatbed scanners. Some illustrations of the potential of the Ukrainian
plate archives for future reusage are given and some compiled plate catalogues are presented on the basis of data from the
Wide-Field Plate Database. 相似文献
210.
Boris Shustov Ana I. Gómez de Castro Mikhail Sachkov Alexander Moisheev Evgeny Kanev Javier López-Santiago Oleg Malkov Dmitry Nasonov G. Belén Perea Néstor Sánchez Igor Savanov Andrey Shugarov Sergey Sichevskiy Oleg Vlasenko Javier Yañez 《Astrophysics and Space Science》2014,354(1):155-161
The World Space Observatory Ultraviolet (WSO-UV) is the space mission that will grant access to the ultraviolet (UV) range in the post Hubble epoch. WSO-UV is equipped with instrumentation for imaging and spectroscopy and it is fully devoted to UV astronomy. In this article, we outline the WSO-UV mission model and present the current status of the project. 相似文献