نتایج جستجو برای: tholeiitic basalt

تعداد نتایج: 3809  

Journal: :Marine Geology 2022

The submarine Azores Plateau in the Central Northern Atlantic has generally been considered to represent a large igneous plateau formed some 10 Ma by widespread volcanism, however lack of age progression amongst younger and subaerial an irregular distribution platform-related magmas east west Mid-Atlantic Ridge, strong tectonic stress regime, abundant tholeiitic compositions that reflect initia...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1979
G J Wasserburg D J Depaolo

A simplified model of earth structure based on the Nd and Sr isotopic characteristics of oceanic and continental tholeiitic flood basalts is presented, taking into account the motion of crustal plates and a chemical balance for trace elements. The resulting structure that is inferred consists of a lower mantle that is still essentially undifferentiated, overlain by an upper mantle that is the r...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Yarin Hadid Shay Tzur Tomáš Pavlícek Radim Šumbera Jan Šklíba Matěj Lövy Ori Fragman-Sapir Avigdor Beiles Ran Arieli Shmuel Raz Eviatar Nevo

Sympatric speciation has been controversial since it was first proposed as a mode of speciation. Subterranean blind mole rats (Spalacidae) are considered to speciate allopatrically or peripatrically. Here, we report a possible incipient sympatric adaptive ecological speciation in Spalax galili (2n = 52). The study microsite (0.04 km(2)) is sharply subdivided geologically, edaphically, and ecolo...

2015
M. G. Babechuk M. Widdowson M. Murphy

a r t i c l e i n f o chemostratigraphy of two contrasting Deccan Traps weathering profiles – an ancient, deeply weathered laterite, and a younger (Quaternary), more moderately weathered saprolite – are used to reconstruct different aspects of basalt weathering. Precision of the HFSE analyses is demonstrated through a report of the long-term concentrations and ratios determined in United States...

Journal: :The Journal of the Geological Society of Japan 2003

Journal: :journal of sciences, islamic republic of iran 2009
a.r. shaker ardakani

the upper cretaceous ganj complex, a part of the jazmurian ophiolitic belt, is located on the western boundary of jazmurian depression and separated from kahnuj ophiolitic complex by north-south trending jiroft fault. the complex consists of lava flows, pillow lavas, acidic plutonic and sedimentary rocks which are intruded by northwest-southeast trending dykes. it does not resemble a classical ...

Journal: :Canadian Journal of Earth Sciences 2023

The Amer Belt, hosting eleven informal formations of the supergroup, is proposed as type area for four regional Paleoproterozoic sequences (Ps1–Ps4) in central Rae Craton, western Churchill Province. ca. 1.9–1.865 Ga Snowbird orogeny (D P1 ) affected only Ps1–Ps3, whereas 1.87–1.81 Hudsonian P2 all four. Sequence Ps1 Ayagaq Lake formation (<2.3 quartzite) initiates schistose basal polymict o...

2005
P. Senthil Kumar

[1] Lonar crater is a simple, bowl-shaped, near-circular impact crater in the 65 Myr old Deccan Volcanic Province in India. As Lonar crater is a rare terrestrial crater formed entirely in basalt, it provides an excellent opportunity to study the impact deformation in target basalt, which is common on the surfaces of other terrestrial planets and their satellites. The present study aims at docum...

2002
J. J. Gillis B. L. Jolliff

Introduction: In a continuing study of mare basalts and factors affecting their composition, volume, and eruption duration (e.g., incorporation of K-U-Th), we examine the compositions of mare basalts and nonmare units on the floor of Australe Basin. This pre-Nectarian basin is located on the southeastern limb of the Moon (52°S, 95°E) [1], far removed from Th-enriched proximal and possible antip...

A. A Nourbakhsh H MonajatiZadeha R. DavoudianDehkordi

Recently, geopolymer binders have been considered because of low cost, simple processes for synthesis and many raw materials in nature. Geopolymer with brittle nature does not have high strength and cannot be used alone for structural materials. Therefore, to use in different structures, the composite which is reinforced with fibers such as carbon, glass, basalt, etchasbeen used. In this resear...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید