نتایج جستجو برای: Eocene alkaline rocks
تعداد نتایج: 68026 فیلتر نتایج به سال:
the neogene intrusion masses in the noudeh-enghelab area located to the north of sabzevar ophiolite have cut the late cretaceous ophiolitic rocks, sedimentary- volcanic and eocene volcanic rocks and have been covered by pliocene and quaternary deposits. the margin is of lava with basalt, phyric andesite-basalt and andesite and the central parts (dome shaped) composed of phyric andesite-trachyan...
Petrography and chemistry of minerals showing that Eocene alkaline volcanic rocks in southwestern of Germi (Talesh zone, NW Iran) mostly have basaltic composition. Mineralogically these rocks are composed of diopsidic clinopyroxene and labradoritic plagioclase phenocrysts. The microlithic and glassy groundmass composed of sanidine, clinopyroxene, biotite, pargasitic amphibole and magnetite asso...
Sixteen new K-Ar dates are presented from Tasmanian and Bass Basin basalts, more than doubling the previously published number. Eight volcanic regions are described, based on boundaries established on the range of the basalt types contained in each geographic region. Volcanism occurred within the span from Eocene to Miocene (47 to 13+ Ma), but mainly within the time range Middle Eocene to Early...
Post-Eocene volcanic rocks of Alborz tectonic zone located in the NE of Qazvin, composed of rhyolite, trchydacite, trachyandesite, andesite, trachybasalt and basalt with porphyritic textures, pyroclastic rocks and volcanic red breccia which are settled alternatively on Eocene pyroclastics and tuffs. The volcanic rocks are enriched in LIL and depleted in HFS elements which may indicate a calc-al...
The study area is located in the east of Ahar town in Eastern Azerbaijan Province and is part of the Ahar-Arasbaran Cenozoic magmatic belt of NW Iran. The geological units of the Eocene age are volcanic rocks with andesite, latite - andesite and basaltic andesite composition. Khankandi and Useflu Oligocene intrusive bodies intruded in the volcanic rocks and caused widespread alteration and copp...
The study area is located at 130 km northwest of Nehbandan in South of Khorasan and is a part of the rectangular Chahvak (Dehsalm). Dacite, rhiodacite, andesite, rhyolite, tuff and lithic tuff with Eocene age are recognized in the study area. According to mineralogy, mentioned rocks include plagioclase, quartz, pyroxene, amphibole, biotite and alkaline feldspar. Plagioclase consists of zonal st...
arghash – ghasem-abad area in ne iran is located in the rim of the sabzevar structural zone. tertiary outcrops include granite and quartz monzodiorite porphyry associated with dacite and andesite volcanic rocks. in the study area, quartz gabbro and quartz monzodiorite dykes intruded the older rocks. granite and volcanic rocks host au-sb-bearing quartz-calcite veins. mineralized veins are mainly...
chaldoran area in nw of iran has mesozoic oceanic crust basement. the studied rocks of this region can be divided into three groups: ophiolitic gabbros and pillow lavas, ophiolitic volcanoclastics and eocene lava flows. ophiolitic mafic rocks show continental volcanic arc natures and eocene lava flow shows oib-like nature. during the mesozoic,the chaldoran region was situated in the active cont...
The Eocene rocks in Shabraweet area comprise the Lower, Middle and Upper Eocene stages. Each stage consists of only one rock unit; the Minia Formation, the Mokattam Formation and the Maadi Formation, respectively. The Minia Formation shows angular unconformity relationship with the underlying Cretaceous rocks and disconformity relationship with the overlying Mokattam Formation. The Maadi Format...
The Eocene volcanic rocks exposed in the NW Sechangi area of Lut block, include pyroclastic deposits and lavas. These volcanic rocks are basalt, basaltic andesite, andesite, andesite-trachyandesite, trachydacite, dacite and rhyolite-ignimbrite in composition. Based on our field observations, the volcanic rocks erupted in four stages in the aquous to subaerial environments. The volcanic rocks ar...
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