نتایج جستجو برای: tholeiitic basalt
تعداد نتایج: 3809 فیلتر نتایج به سال:
[1] These first measurements of specific surface area (SSA) of bulk samples of subsurfacemarine basalts were undertaken to determine the potential area available for microbial colonization. SSA ranged from 0.3 to 52 m/g of basalt with the lowest value coming from pillow basalt and the highest value from breccia. The average for massive and pillow basalts combined was 2.3 m/g. The total specific...
Tracing interisland and interarchipelago movements of people and artifacts in prehistoric Polynesia has posed a challenge to archaeologists due to the lack of pottery and obsidian, two materials most readily used in studies of prehistoric trade or exchange. Here we report the application of nondestructive energy-dispersive x-ray fluorescence (EDXRF) analysis to the sourcing of Polynesian artifa...
Epigenetic modifications play significant roles in adaptive evolution. The tumor suppressor p53, well known for controlling cell fate and maintaining genomic stability, is much less known as a master gene in environmental adaptation involving methylation modifications. The blind subterranean mole rat Spalax eherenbergi superspecies in Israel consists of four species that speciated peripatricall...
In this work, an economical modifier silane agent—KH550—was used for surface treatment of basalt fiber. Then, a biodegradable poly(butylene succinate) (PBS)/modified basalt fiber (MBF) biocomposite was successfully developed. The effects of silane treatment and fiber mass content on crystalline structure, isothermal crystallization process and mechanical performance of composites were evaluated...
Lithium (Li), the lightest of the alkali elements, has geochemical properties that include high aqueous solubility (Li is the most fluid mobile element) and high relative abundance in basalt-forming minerals (values ranking between 0.2 and 12 ppm). Li isotopes are particularly subject to fractionation because the two stable isotopes of lithium-7Li and 6Li-have a large relative mass difference (...
The oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the...
[1] The Hawaii Scientific Drilling Project recovered 3 km of basalt by coring into the flank of Mauna Kea volcano at Hilo, Hawaii. Rocks recovered from deeper than 1 km were deposited below sea level and contain considerable fresh glass. We report electron microprobe analyses of 531 glasses from the submarine section of the core, providing a high-resolution record of petrogenesis over ca. 200 K...
Abstract La Réunion Island includes two major volcanic systems. About 0·5 Myr ago, Piton des Neiges volcano declined, while de la Fournaise grew on its flank. Since then the shield has produced homogeneous lavas with chemical compositions transitional between alkali and tholeiitic basalts. In April 2007, emitted a very small volume of trachytic pumice during largest historical eruption. We cond...
We report the surface exploration by the lunar rover Yutu that landed on the young lava flow in the northeastern part of the Mare Imbrium, which is the largest basin on the nearside of the Moon and is filled with several basalt units estimated to date from 3.5 to 2.0 Ga. The onboard lunar penetrating radar conducted a 114-m-long profile, which measured a thickness of ∼5 m of the lunar regolith ...
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