Results 91 to 100 of about 21,763 (249)

Moon's volcanic history revealed in glassy spherules from Apollo 17 soil 76501

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Rapidly quenched droplets of pyroclastically erupted lava are common in lunar regolith at landing sites proximal to the maria. Here, we document the U‐Pb chronologies, major element, and trace element compositions of picritic glassy particles from Apollo 17 regolith sample 76501. These particles are dominated by high‐Ti compositions similar to
Alexander A. Nemchin   +9 more
wiley   +1 more source

SHRIMP U-Pb zircon dating on Nyainqentanglha granite in central Lhasa block

open access: yesChinese Science Bulletin, 2004
The Nyainqentanglha granite, a batholith with an area of 1500 km2 in the central Lhasa block, comprises mainly medium-fine-grained biotite monzonitic granite and medium-coarse-grained biotite monzonitic granite. Their contact relationship suggests that the medium-fine-grained biotite monzonitic granite was crystallized earlier than the medium-coarse ...
Qisheng Liu   +6 more
openaire   +2 more sources

Malignant melanoma of the urethra: a rare histologic subdivision of vulvar cancer with a poor prognosis [PDF]

open access: yes, 2012
Malignant melanoma of the urethra is a rare tumour that is difficult to diagnose and treat, resulting in a poor prognosis. In this paper, we present the case of a 65-year-old woman who was referred to a gynaecologist because of a urethral mass that ...
Alkatout, Ibrahim   +8 more
core   +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

Near‐Synchronous Cambrian Evolution of the Transbrasiliano‐Kandi‐4°50′ Shear Zone in South America and Africa

open access: yesTerra Nova, EarlyView.
ABSTRACT The Transbrasiliano‐Kandi‐4°50′ (TK4) shear zone in western Gondwana crosscuts South America and NW Africa for at least 6000 km. Despite its impressive size, the timing of the main episode of dextral ductile shearing is uncertain. We present detailed in situ multi‐mineral geochronology of mylonites from both Brazil and Algeria supporting that ...
F. A. Caxito   +4 more
wiley   +1 more source

Evolution of Siderian juvenile crust to Rhyacian high Ba-Sr magmatism in the Mineiro Belt, southern São Francisco Craton [PDF]

open access: yes, 2018
Plutonic rocks from the Mineiro Belt, Brazil record a delayed onset of the transition from TTG to sanukitoid-type magmatism (high Ba-Sr), starting during the Siderian magmatic lull when little juvenile magma was added to the continental crust.
Fowler, Mike   +6 more
core   +2 more sources

Dating C/S Structures in Syntectonic Granites by In Situ Rb‐Sr Analyses on Muscovite

open access: yesTerra Nova, EarlyView.
ABSTRACT The interplay of crystallisation, deformation and fluid–rock interactions makes deciphering geochronological information complex in syntectonic granites. In this study, we apply in situ Rb‐Sr analyses to selected samples from the Questembert Variscan syntectonic granite in Western France, which was emplaced along the South Armorican Shear Zone
Philippe Boulvais, Romain Tartèse
wiley   +1 more source

Turning Trash Into Treasure: Extracting Meaning From Discordant Data via a Dedicated Application

open access: yesGeochemistry, Geophysics, Geosystems
Zircon U–Pb geochronology is a vital tool for dating geological events, but interpreting discordant zircon ages—often the result of Pb loss due to fluid‐rock interactions—remains challenging.
Lucy M. Mathieson   +2 more
doaj   +1 more source

Detrital-zircon geochronology and provenance of the Ocloyic synorogenic clastic wedge, and Ordovician accretion of the Argentine Precordillera terrane [PDF]

open access: yes, 2015
The Precordillera terrane in northwestern Argentina is interpreted to be anexotic (Laurentian) continental fragment that was accreted to western Gondwanaduring the Ordovician. One prominent manifestation of the subductionand collision process is a Middle?
Astini, Ricardo Alfredo   +3 more
core   +1 more source

Thermochronology of the modern Indus River bedload: New insight into the controls on the marine stratigraphic record [PDF]

open access: yes, 2004
The Indus River is the only major drainage in the western Himalaya and delivers a long geological record of continental erosion to the Arabian Sea, which may be deciphered and used to reconstruct orogenic growth if the modern bedload can be related to ...
Ali Athar Khan   +90 more
core   +2 more sources

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