نتایج جستجو برای: pillow lavas

تعداد نتایج: 1995  

Journal: :Geological Magazine 1911

Journal: :Science 2004
Harald Furnes Neil R Banerjee Karlis Muehlenbachs Hubert Staudigel Maarten de Wit

Pillow lava rims from the Mesoarchean Barberton Greenstone Belt in South Africa contain micrometer-scale mineralized tubes that provide evidence of submarine microbial activity during the early history of Earth. The tubes formed during microbial etching of glass along fractures, as seen in pillow lavas from recent oceanic crust. The margins of the tubes contain organic carbon, and many of the p...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Hubert Staudigel Harald Furnes Maarten DeWit

Microbial corrosion textures in volcanic glass from Cenozoic seafloor basalts and the corresponding titanite replacement microtextures in metamorphosed Paleoarchean pillow lavas have been interpreted as evidence for a deep biosphere dating back in time through the earliest periods of preserved life on earth. This interpretation has been recently challenged for Paleoarchean titanite replacement ...

Journal: :Geological Society of America Bulletin 1914

Journal: :Geological Magazine 1959

2011
Mako Hill Déthié Sarr Meissa Fall Papa Malick Ngom Mapathé Ndiaye

This work shows the Kédougou-Kéniéba inlier (eastern Senegal) pillow lavas behavior from laboratory to field. Some uniaxial tests are carried out on five types of specimens of pillow lavas. These types of specimens are: microscopically healthy rock, fractured rock without filling, fractured rock filled with epidote, chlorite and calcite and rocks with tension crack filled with quartz. The Young...

ترابی, قدرت, شیردشت زاده, نرگس , عبداللهی, الهام ,

Pillow lavas are one of the important rock units of Nain ophiolite. Rock forming minerals of Nain ophiolite pillow lavas are chloritized olivine, plagioclase, clinopyroxene (augite), Cr-spinel, magnetite, amphibole, chlorite, pumpellyite, epidote, prehnite and calcite. Whole rock geochemical analyses and composition of clinopyroxenes and chromian spinels of these rocks indicate that they are si...

Journal: :زمین شناسی اقتصادی 0
نرگس شیردشت زاده قدرت ترابی رامین صمدی

the nain and ashin ophiolites are located in northeastern isfahan province, in western central-east iranian microplate. pillow lavas are one of the most significant cretaceous rock units. the lower partial melting degree in mantle peridotites of ashin ophiolite, and the derived melt by melting their clinopyroxene caused a more basic (basalt) and enriched nature for the ashin pillow lavas, where...

Journal: :Science 2007
Warren B Hamilton

The claim by Furnes et al. (Reports, 23 March 2007, p. 1704) that Greenland metavolcanic rocks require Paleoarchean sea-floor spreading is incompatible with their own data. The purported sheeted dikes have the composition of pyroxenitic komatiite and could not have fed the adjacent ferroandesitic pillow lavas. Neither type has ophiolitic analogs, and both are likely ensialic.

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید