scholarly journals Tectonic-magmatic position of Paleogene volcanic rocks of Roudbar (north of Iran)

2021 ◽  
Vol 12 (2) ◽  
pp. 140-156
Author(s):  
zahra Shafeie ◽  
Mohammad Ali Arian ◽  
Shahrouz Haghnazar
Keyword(s):  
2021 ◽  
Vol 21 (Suppliment-1) ◽  
pp. 2224-2234
Author(s):  
Leila Abbaspour Shirjoposht ◽  
Sayed Jamal al-Din Sheikh Zakariaee ◽  
Mohammad Reza Ansari ◽  
Mohammad Hashem Emami

2016 ◽  
Vol 06 (10) ◽  
pp. 1296-1311
Author(s):  
Zahra Shafeie ◽  
Mohammad Ali Arian ◽  
Shahrouz Haghnazar ◽  
Mansour Vossoughi Abedini

2020 ◽  
Vol 33 (02) ◽  
pp. 511-524
Author(s):  
Leila Abbaspour Shirjoposht ◽  
Sayed Jamal al-Din Sheikh Zakariaee ◽  
Mohammad Reza Ansari ◽  
Mohammad Hashem Emami

The Ziaran volcanic Belt (ZVB), North of Iran contains a number of intra-continental alkaline volcanic range situated on South part of central Alborz Mountains, formed along the localized extensional basins developed in relation with the compressional regime of Eocene. The mid-upper Eocene volcanic suite comprises the extracted melt products of adiabatic decompression melting of the mantle that are represented by small volume intra-continental plate volcanic rocks of alkaline volcanism and their evaluated Rocks with compositions representative of mantle-derived, primary (or near-primary) melts. Trace element patterns with significant enrichment in LILE, HFSE and REEs, relative to Primitive Mantle. Chondrite-normalized of rare earth elements and enrichment in incompatible elements and their element ratios (e. g. LREE/HREE, MREE/HREE, LREE/MREE) shown these element modelling indicates that the magmas were generated by comparably variable degrees of partial melting of garnet lherzolite and a heterogeneous asthenospheric, OIB mantle sources.


Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.


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