250 Ma metagranitoid from Drangovo Village: a new discovery of Permo-Triassic magmatism in the Eastern Rhodopes, Bulgaria

This short communication reports a 251.4 ± 6.8 Ma age of a Permo-Triassic metagranitoid (augen gneiss) in the Bulgarian part of the Eastern Rhodopes. The rock is intruded by the early Eocene Drangovo pluton and represents part of the upper metamorphic unit of the Kessebir dome. The analyzed sample has slightly peraluminous (ASI = 1.11) granitic composition with SiO2 = 70.6 wt.%. It is enriched in LILE and LREE and depleted in HREE, with a deep Eu (Eu/Eu* = 0.49) anomaly consistent with garnet and plagioclase fractionation. The large number of xenocrystic zircons, along with the low (780 °C) crystallization temperature and petrochemical data, suggests significant assimilation of basement rocks by the granitic magma. The rock has a subduction-related signature.

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Melting relations of Tertiary granitic rocks in Skye and Rhum

Mineralogical Magazine and Journal of the Mineralogical Society ◽

10.1180/minmag.1963.033.262.02 ◽

1963 ◽

Vol 33 (262) ◽

pp. 533-562 ◽

Cited By ~ 35

Author(s):

G. M. Brown

Keyword(s):

Partial Melting ◽

Vapour Pressure ◽

Granitic Rocks ◽

Granitic Magma ◽

Water Vapour Pressure ◽

Melting Behaviour ◽

Basement Rocks ◽

The Stability ◽

Melting Experiments ◽

Melting Relations

SummaryThe results of reconnaissance melting experiments on Tertiary granophyres and Torridonian arkose at 1000 kg/cm2 water-vapour pressure show that the melting behaviour of these rocks can be viewed in relation to the synthetic system NaAlSi3O8-KAlSi3O8-SiO2-H2O. By analogy with this system, P-T curves are constructed for Skye granophyres and, viewed in relation to the stability of tridymite, the depth and temperature of emplacement are estimated. Further estimates of the likely depth of magma generation, and the behaviour of the country rocks at that level, lead to the conclusion that most of the Tertiary granitic rocks were produced through partial melting of Lewisian basement rocks, the heat being provided by the basic magmas available during this volcanic episode. Subsidiary amounts of granitic magma were similarly derived from higher levels, within the Torridonian arkose group, and evidence is provided for the depth and temperature at which these, together with tridymite-bearing metamorphosed arkose in Rhum, were produced.

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Geochemistry and tectonic significance of augen gneisses from the southern Menderes Massif (West Turkey)

Geological Magazine ◽

10.1017/s0016756800013613 ◽

1995 ◽

Vol 132 (3) ◽

pp. 287-301 ◽

Cited By ~ 33

Author(s):

E. Bozkurt ◽

J. A. Winchester ◽

R. G. Park

Keyword(s):

Lower Crust ◽

Early Eocene ◽

Late Oligocene ◽

Calc Alkaline ◽

Menderes Massif ◽

Early Oligocene ◽

Basement Rocks ◽

Metamorphic Basement ◽

Tectonic Significance ◽

Water Saturated

AbstractThe protoliths of mylonitized augen gneisses exposed in the southern sector of the Menderes Massif (West Turkey) are calc-alkaline, peraluminous, S-type, late- to post-tectonic tourmaline- and garnet-bearing, two-mica leucogranites. They cut and post-date the fabrics of the ‘main Menderes metamorphism’ which took place between the early Eocene and early Oligocene and intrude metamorphic basement rocks comprising the so-called ‘Palaeozoic schist envelope’ of the massif. They are themselves cut by an extensive network of tourmaline-rich dykes. Chemical, mineralogical, isotopic and field relations suggest that the granitic protolith crystallized from a boron-rich, water-saturated melt, derived from partial melting of metagreywacke in the lower crust during peak Barrovian-type metamorphism. The protolith was probably emplaced during lateorogenic extensional collapse of the thickened crust in west Turkey during late Oligocene time.

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A quartzite inclusion in the R~nne Granite - the fist Danish sediment?

Bulletin of the Geological Society of Denmark ◽

10.37570/bgsd-1996-43-01 ◽

1996 ◽

Vol 43 ◽

pp. 4-8

Author(s):

Henrik Friis

Keyword(s):

Sedimentary Rocks ◽

Granitic Magma ◽

Carbonate Minerals ◽

Thin Sections ◽

Future Studies ◽

Mineral Inclusions ◽

Basement Rocks ◽

Quartz Grains ◽

Intergranular Space

The original thin sections from a quartzite inclusion in the RØnne Granite described by Karen Callisen in 1934 have been reexarnined. They appear to represent a sandstone, which has been strongly recrystallized in the granite, but which has retained some evidence of the original fabric. It is concluded that the sandstone was either still porous or was carbonate cemented when it was included in the granitic magma. Part of the intergranular space has been filled by granitic minerals, mainly microcline, but carbonate minerals are important. Some of the recrystallized quartz grains contain many mineral inclusions as well as liquidlgas inclusions. It is suggested that future studies of sedimentary rocks included in the basement rocks of Bornholm may give important knowledge on intmsion depth and temperature of the granites.

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Ultrastructure of primary spermatocyte in fish (Tilapia: Oreochromis niloticus): The synaptonemal complex

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143067 ◽

1986 ◽

Vol 44 ◽

pp. 288-289

Author(s):

T. Guha ◽

A. Q. Siddiqui ◽

P. F. Prentis

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Synaptonemal Complex ◽

Oreochromis Niloticus ◽

Short Communication ◽

Primary Spermatocyte ◽

Mitotic Division ◽

Meiotic Cell ◽

Electron Microscope Level ◽

Homologous Chromosomes

The Primary Spermatocytes represent a stage in spermatogenesis when the first meiotic cell division occurs. They are derived from Spermatogonium or Stem cell through mitotic division. At the zygotene phase of meiotic prophase the Synaptonemal complex appears in these cells in the space between the paired homologous chromosomes. Spermatogenesis and sperm structure in fish have been studied at the electron microscope level in a few species? However, no work has yet been reported on ultrastructure of tilapia, O. niloticus, spermatozoa and spermatogenetic process. In this short communication we are reporting the Ultrastructure of Primary Spermatocytes in tilapia, O. niloticus, and the fine structure of synaptonemal complexes seen in the spermatocyte nuclei.

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The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176459 ◽

1990 ◽

Vol 48 (4) ◽

pp. 664-665

Author(s):

N. Rozhanski ◽

A. Barg

Keyword(s):

High Temperature ◽

Crystallization Temperature ◽

Diffusion Barriers ◽

Sio2 Layer ◽

Si Substrate ◽

Cross Sectional ◽

Plan View ◽

Temperature Range ◽

Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

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The crystallography characteristic of (Mn,Fe)S single crystal

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177623 ◽

1990 ◽

Vol 48 (4) ◽

pp. 898-899

Author(s):

Jiang Xishan

Keyword(s):

Single Crystal ◽

Cast Steel ◽

Point Group ◽

Central Area ◽

Hexagonal Crystal ◽

Growth Step ◽

Left And Right ◽

Relationship Of ◽

Fcc Structure ◽

New Discovery

This paper reports the growth step pattern and morphology at equilibrium and growth states of (Mn,Fe)S single crystal on the wall of micro-voids in ZG25 cast steel by using scanning electron microscope. Seldom report was presented on the growth morphology and steppattern of (Mn,Fe)S single crystal.Fig.1 shows the front half of the polyhedron of(Mn,Fe)S single crystal,its central area being the square crystal plane,the two pairs of hexagons symmetrically located in the high and low, the left and right with a certain, angle to the square crystal plane.According to the symmetrical relationship of crystal, it was defined that the (Mn,Fe)S single crystal at equilibrium state is tetrakaidecahedron consisted of eight hexagonal crystal planes and six square crystal planes. The macroscopic symmetry elements of the tetrakaidecahedron correpond to Oh—n3m symmetry class of fcc structure,in which the hexagonal crystal planes are the { 111 } crystal planes group,square crystal plaits are the { 100 } crystal planes group. This new discovery of the (Mn,Fe)S single crystal provides a typical example of the point group of Oh—n3m.

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Scanning Transmission Electron Microscopy of Polyethylene Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001069 ◽

1980 ◽

Vol 38 ◽

pp. 242-245

Author(s):

F. Khoury ◽

L. H. Bolz

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Crystallization Temperature ◽

Scanning Transmission Electron Microscopy ◽

Growth Habit ◽

Lateral Growth ◽

Scanning Transmission Electron ◽

Transmission Electron ◽

Scanning Transmission ◽

Growth Habits

The lateral growth habits and non-planar conformations of polyethylene crystals grown from dilute solutions (<0.1% wt./vol.) are known to vary depending on the crystallization temperature.1-3 With the notable exception of a study by Keith2, most previous studies have been limited to crystals grown at <95°C. The trend in the change of the lateral growth habit of the crystals with increasing crystallization temperature (other factors remaining equal, i.e. polymer mol. wt. and concentration, solvent) is illustrated in Fig.l. The lateral growth faces in the lozenge shaped type of crystal (Fig.la) which is formed at lower temperatures are {110}. Crystals formed at higher temperatures exhibit 'truncated' profiles (Figs. lb,c) and are bound laterally by (110) and (200} growth faces. In addition, the shape of the latter crystals is all the more truncated (Fig.lc), and hence all the more elongated parallel to the b-axis, the higher the crystallization temperature.

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