نتایج جستجو برای: Late Neoproterozoic-Early Cambrian schists

تعداد نتایج: 817880  

Journal: :journal of sciences, islamic republic of iran 2012
j. izadyar

late neoproterozoic-early cambrian schists have been occurred in southwest of zanjan city from the soltanieh belt. the soltanieh belt in northwest of iran is uplifted basement of precambrian-paleozoic in main central iran zone and includes outcrops of precambrian, paleozoic and mesozoic formations. late neoproterozoic-early cambrian schists, the oldest stratigraphy unit in the region, consist o...

J. Izadyar

Late Neoproterozoic-Early Cambrian schists have been occurred in southwest of Zanjan city from the Soltanieh belt. The Soltanieh belt in northwest of Iran is uplifted basement of Precambrian-Paleozoic in main central Iran zone and includes outcrops of Precambrian, Paleozoic and Mesozoic Formations. Late Neoproterozoic-Early Cambrian schists, the oldest stratigraphy unit in the region, consist o...

اشرفی, اکرم , ایزدیار, جواد , نصیحت شنو, نازیلا ,

Late Neoproterozoic- Early Cambrian schists exposed in southwest of Zanjan in northwest Iran.  Intrusion of Tertiary Korramdaragh monzogranite body within these schists have caused crystallization of porphyroblasts of hexagonal cordierite with cyclic radial sixling twin structure.  Hexagonal cordierite consists of six optically sectors.   Under microscope with crossed polarized, all of the sect...

Journal: :Geological Society, London, Special Publications 2008

Journal: :Precambrian research 1995
A J Kaufman A H Knoll

The recent proliferation of stratigraphic studies of delta 13C variation in carbonates and organic C in later Neoproterozoic and basal Cambrian successions (approximately 850-530 Ma) indicates a strong oscillating trend in the C-isotopic composition of surface seawater. Alone, this trend does not adequately characterize discrete intervals in Neoproterozoic time. However, integrated with the vec...

حسینی, سید حسین, صادقیان, محمود , قاسمی, حبیب اله , مینگو, جای ,

The Band-e-Hezarchah granitoids mainly include alkali granite and granite. that intruded in Late Neoproterozoic metamorphic rocks. Orthoclase, microcline, plagioclase, quartz and biotite are the main rock-forming minerals. Plagioclase is mostly albite and oligoclase with Si = 2.57-2.7 a.p.f.u. and An0.4–12.6. Biotite is mostly siderophyllite, with Si = 4.30-6.22 a.p.f.u. and XMg= 0.025 - 0.859....

2013
P. N. Kolosov

Calcified rock-forming marine filamented benthic microand macrophytes of Dzhelindia Kolosov, 1970 (Figure 1(а)) and Chaptchaica Kolosov, 1975 (Figure 1(b)) genera, thrived in Neoproterozoic (1000 541 million years ago) Siberia together with cyanobacteria. Their belonging to Rhodophyta is well-grounded. These and other Neoproterozoic rodofits, as well as Epiphyton Bornemann 1886 (Figure 1(c)) an...

2007
JONATHAN R. HENDRICKS BRUCE S. LIEBERMAN

ONE of John Shergold’s abiding research interests, and an area in which he made fundamental contributions to the fields of palaeontology and geology, was the study of Cambrian arthropods in general, and trilobites in particular (e.g., Shergold 1977, 1988, 1991; Shergold et al. 1990; Shergold & Laurie 1997). Here we focus on what Cambrian arthropods, including trilobites, can tell us about the n...

احمدی مقدم, پریچهر, احمدی پور, حمید, مرتضوی, محسن, پوستی, محمد,

The Hormuz Formation is a sequence of lithologically various evaporitic–volcanic rocks in salt domes where the volcanic rocks are dominantly acidic, generally with less than one third basic volcanics. It was formed in the Late Proterozoic (640–620 Ma)/Neoproterozoic–Early Cambrian, as a result of sub-basin rifting in the northern part of the Arabian plate, throughout most of the Persian Gulf Ba...

Journal: :Geological Quarterly 2022

The Staré Město Belt (SMB) in the Central Sudetes forms a Variscan tectonic boundary zone that is located between Saxothuringian and Brunovistulian terranes of Bohemian Massif. three thrust-bounded upper, middle lower lithotectonic units SMB are composed metasedimentary Late Cambrian metavolcanic rocks. A new LA-ICPMS zircon geochronology supported by typology studies mica schists upper unit mi...

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