نتایج جستجو برای: volcanic belt

تعداد نتایج: 31742  

2000
E. H. Chown

The uppermost section of the Hunter Mine group (HMG) (2728 Ma), a bimodal volcanic complex in the Abitibi greenstone belt, contains both oxide and carbonate facies banded iron-formation (BIF). This paper explores the relationship between volcanic activity and the development of the two types of iron-formation. The oxide facies, represented by chert-jasper-magnetite iron-formation is widespread ...

2007
Yih-Min Wu Chien-Hsin Chang Li Zhao J. Bruce H. Shyu Yue-Gau Chen Kerry Sieh Jean-Philippe Avouac

[1] In this study, a large collection of 41,141 S-P times from the untapped records of the Taiwan Strong Motion Instrumentation Program (TSMIP) network is combined with the P and S wave arrival times from the Taiwan Central Weather Bureau Seismic Network (CWBSN) to image the Vp and Vp/Vs structures beneath Taiwan. The records from the 680 TSMIP stations throughout Taiwan in the past 15 years en...

2004

The northern Asia, including the southern territories of Russia, Kazakhstan, Uzbekistan, Mongolia and the northern China is known as an important distribution region of uranium deposits and occurrences. Since the 60s of 20th century, after the successful development of in-situ leach technology for sandstone-hosted uranium deposits, numerous uranium deposits previously discovered in Kazakhstan a...

سلطانی, افسانه , فردوست, فرج الله ,

about 50 Km northwest of Bardeskan, Eocene volcanic and volcano sedimentary rocks of magmatic belt of north central Iran structural zone are host of Abri copper deposit. Volcanic rocks dominantly have andesitic, basalt and andesitic basalt composition, and manifested such as submarine lava flows, brecciated lavas in the present of water (agglomerate), or ash and fragmented volcanic rocks (tuffi...

Journal: :زمین شناسی اقتصادی 0
عباس گل محمدی محمد حسن کریم پور آزاده ملکزاده شفارودی سید احمد مظاهری

sangan magnetite skarn mine is located 300 km southeast of mashhad, along the eastern part of khaf-drouneh volcanic-plutonic belt. granitoids from three areas within the sangan mine a, c-north and dardvay were studied. within the study area, three intrusive rocks including biotite-hornblende monzonite porphyry, biotite syenite and syenogranite were recognized. based on field cross cutting, abse...

2000
P. L. Corcoran

Archean volcanic rocks in the mafic-dominated, ca. 2.66–2.69 Ga Point Lake and Beaulieu River belts, Slave Province, Northwest Territories, are significant in demonstrating the facies that characterize specific portions of pillow volcanoes or seamounts, irrespective of tectonic setting. Three distinct localities mapped in detail display facies consistent with: (1) proximal, deep-water, (2) medi...

Journal: :زمین شناسی اقتصادی 0
محمد حسن کریم پور آزاده ملکزاده شفارودی اکبر اسفندیارپور حسن محمدنژاد

neyshabour turquoise mine is located in northwest of neyshabour, southern quchan volcanic belt. eocene andesite and dacite forming as lava and pyroclastic rocks cover most of the area. subvolcanic diorite to syenite porphyry (granitoids of magnetite series) intruded the volcanic rocks. both volcanic and subvolcanic rocks are highly altered. four types of alteration are recognized including: sil...

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