Results 71 to 80 of about 27,222 (235)

Petrology of some oceanic island basalts: PRIMELT2.XLS software for primary magma calculation [PDF]

open access: yes, 2008
PRIMELT2.XLS software is introduced for calculating primary magma composition and mantle potential temperature (TP) from an observed lava composition. It is an upgrade over a previous version in that it includes garnet peridotite melting and it detects ...
Asimow, Paul D., Herzberg, C.
core   +2 more sources

Mapping High‐TDS Groundwater Near Impoundments Using Ground and Waterborne Towed Electromagnetics

open access: yesGroundwater, EarlyView.
Abstract Long‐term monitoring at landfills and impoundments containing coal combustion products (CCPs) or other industrial wastes is essential for detecting possible leachate releases to groundwater and mapping contamination plumes. This study evaluates a novel, non‐invasive geophysical approach—towed time‐domain electromagnetic (TEM) surveys—for non ...
Piyoosh Jaysaval   +4 more
wiley   +1 more source

Comet 9P/Tempel 1: Interpretation with the Deep Impact Results

open access: yes, 2008
According to our common understandings, the original surface of a short-period comet nucleus has been lost by sublimation processes during its close approaches to the Sun. Sublimation results in the formation of a dust mantle on the retreated surface and
Croft S. K.   +9 more
core   +1 more source

Application of palynological data to the chronology of the Palaeogene lava fields of the British Province: implications for magmatic stratigraphy [PDF]

open access: yes, 1997
New high-precision ages, determined from palynomorph assemblages within intercalated sedimentary deposits, are presented for the Palaeogene lava fields (Skye, Mull and Antrim) of the British Province. These data reveal very rapid averaged eruption rates (
Bell, B.R., Jolley, D.W.
core   +1 more source

Noble Gases in Mantle Plumes

open access: yesScience, 2001
Trieloff et al . ([1][1]) provided neon isotope data to argue that mantle neon originates as a trapped component in meteorites rather than having a pristine solar composition. That finding, if true, has important consequences for understanding the mechanism of volatile input into the mantle ...
Ballentine, C, Porcelli, D, Wieler, R
openaire   +2 more sources

Exploring the Gravimetric and Geochronological Links in Ancient Terranes of the São Francisco Craton and Borborema Province, NE‐Brazil

open access: yesTerra Nova, EarlyView.
ABSTRACT Deep crustal fragments and structural lineaments identified through satellite gravity data provide evidence for the extension of the reworked ancient basement of the Central African Block into the northern São Francisco Craton and southern Borborema Province.
Douglas Teixeira Martins   +3 more
wiley   +1 more source

The constant oxidation state of Earth’s mantle since the Hadean

open access: yesNature Communications
Determining the evolutionary history of mantle oxygen fugacity (fo2) is crucial, as it controls the fo2 of mantle-derived melts and regulates atmospheric composition through volcanic outgassing. However, the evolution of mantle fo2 remains controversial.
Fangyi Zhang   +6 more
doaj   +1 more source

Cryogenian Glacial Erosion and Tectonics as Agents of Crustal Recycling

open access: yesTerra Nova, EarlyView.
ABSTRACT Zircon preserves evidence of recycling processes that link surface environments to the mantle. Combined δ18O‐εHf in zircon fingerprints magmatic sources and tracks how crustal material is reworked over time. We apply statistical analyses to a global compilation that apparently resolves shifts in zircon U–Pb, δ18O, and Lu‐Hf data spanning the ...
M. Seraine   +9 more
wiley   +1 more source

Giant Porphyry Copper Deposits Caused by a Slab Jamming in the Mantle Transition Zone

open access: yesTerra Nova, EarlyView.
ABSTRACT Two giant porphyry copper deposits in the Southern Central Andes formed during the Miocene–Pliocene transition when a bend in the subducting Juan de Fernández hotspot chain jammed in the mantle transition zone, causing mega‐scale slab‐kinking. This geometry implies mechanical resistance that caused East–West compression and eventually a thrust‐
Nipaporn Nakrong   +5 more
wiley   +1 more source

Hot mantle upwelling across the 660 beneath Yellowstone [PDF]

open access: yes, 2012
P-to-s receiver functions mapped to depth through P and S body-wave tomography models image continuous 410 and 660 km discontinuities beneath the area covered by USArray prior to the year 2011. Mean depths to the 410 and 660 km discontinuities of 410 and
Dueker, Kenneth   +3 more
core   +1 more source

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