نتایج جستجو برای: dacite

تعداد نتایج: 251  

پورمعافی, سیدمحمد , یوسف‌زاده, محمدحسین, امامی, محمد هاشم , سبزه‏ئی, مسیب, وثوقی عابدینی, منصور ,

The Tertiary volcanic rocks in the north and west of Birjand are dacite; andesite, basaltic andesite, trachyandesite and rhyolite.They belong to calc- alkaline from magmatic series. Mineralogcal, petrographcal and geochemical evidence show that they have formed in active continental margins. Most andesites and dacites are appeared as volcanic domes or subvolcanic dykes that injected older units...

برقی, بهناز, زرین‌کوب, محمد حسین, سیمونز, وارطان, کلاگری, علی اصغر,

The Beshgaz manganese-bearing veins are located in ~45 km northeast of Birdjand, South-Khorasan, and east of Iran. These veins with 0.1-1.5 m thickness and 4-7 m length are engulfed discordantly within Paleocene (Eocene-Oligocene) volcanic-pyroclastic rocks.  The host of Mn-bearing veins are dacite to rhyo-dacite tuff, lapilli tuff with andesitic and andsi-basaltic fragments in shear zones. The...

اعتمادی, بیژن, تقی‌پور, بتول, قبادی, عبدالهادی,

Nodoushan clay deposit is located about 130km southwest of Yazd city in the Uromieh-Dokhtar volcano-plutonic belt. Based on the field, mineralogical and geochemical studies, the rocks of Nodoushan area are of volcanic type and are composed of dacite, andesite and olivine-basalt, the pyroclastic type (crystalline tuff), and the microgranodioritic intrusive rocks. According to Zr/TiO2 versus SiO2...

کوهساری, امیرحسین, دهقانزاده بافقی, علی اکبر , محمد تراب, فرهاد ,

Gazestan deposit is located about 185 km of Yazd, in the Bafgh – Posht e Badam Metallogenic belt, consists of Infracambrian carbonate, shale, tuff, sandstone and volcanic rocks. Acid to basic green rocks (rhyolite, dacite and basalt) are host for iron and phosphate mineralization. The alteration process is more intence in the volcanic rocks including, actinolite, chloritization, silicification ...

Journal: :Journal of Mineralogical and Petrological Sciences 2022

Groundmass pyroxene crystals in pumice from the 1914 eruption of Sakurajima Japan show varied combinations crystallographic faces (i.e., ‘tracht’). To investigate whether groundmass tracht depends on magma decompression conditions, we performed isothermal single–step experiments hydrous dacite magma. The was held under water–saturated conditions at 920 °C, 120 MPa, and oxygen fugacity no more o...

Journal: :Sustainability 2022

High-level natural radioactivity, geochemical, geological, and radiological hazard assessment of the poorly investigated Wadi Gebeiy Dokhan volcanics rocks are discussed. located in Southwestern Sinai, Egypt, covering an area ~1.3 km2. represented by porphyritic dacite. Geochemically, they have medium-k characters originate from calc-alkaline magma within a arc environment. Along fault plane st...

2005
Obada Kayali

A new patented lightweight aggregates is tested. This type is given the name Flashag. The only solid raw material used to manufacture these aggregates is fly ash. The aggregates are sintered but not pelletized and the process is easy and inexpensive. This paper describes these patented aggregates and compares them with other lightweight and normal-weight aggregates that are used for concrete. T...

2008
Hiromitsu Yamagishi

Sado Island is floating offshore of Niigata on Sea of Japan. This island is 855km2 and composed of Ko-sado (Small Sado) and O-Sado (Large Sado), and both them are arranged in a direction of NNE-SSW. This arrangement are parallel to Kakuda-Yahiko Range, south of Niigata City in the main land. O-Sado has the highest peak of more than 1100 m (Kinpokusan: 1172m), and Ko-Sado of 600 m high peak (Dai...

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