Results 91 to 100 of about 50,106 (261)

The Lomagundi-Jatuli carbon isotopic event recorded in the marble of the Tandilia System basement, Río de la Plata Craton, Argentina [PDF]

open access: yes, 2019
The “Lomagundi-Jatuli event” corresponds to the most important δ13C positive anomaly (≥5‰) globally reported in Palaeoproterozoic marine carbonates (between ∼2.30 and 2.06 Ga).
Ballivian Justiniano, Carlos Alberto   +6 more
core   +1 more source

In situ single‐spot Rb/Sr cosmochronology of roedderite in the Ribbeck aubrite (asteroid 2024 BX1)

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The mineralogy and textures of several fragments from the Ribbeck aubrite were analyzed using a combination of scanning electron microscopy, electron microprobe analysis, μRaman spectroscopy, and laser ablation inductively coupled reaction cell mass spectrometry (LA‐ICP‐MS/MS).
Christopher J. Barnes   +6 more
wiley   +1 more source

Clay mineralogy, chemistry, and diagenesis of late devonian K-bentonite occurrences in northwestern Turkey [PDF]

open access: yes, 2015
Thin beds of tephra (K-bentonites) formed by the diagenesis of volcanic ash are exposed within the limestone-dolomitic limestone successions of the Yilanli formation at Zonguldak and Bartin in northwestern Turkey.
Bozkaya, Ömer   +5 more
core   +1 more source

Mountain‐top spherules: Criteria to identify natural and synthetic particles

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Natural microspherules are important tracers of geologic and environmental processes in modern and ancient deposits. However, anthropogenic contamination can dilute natural collections by releasing synthetic microspherules into the environment.
M. R. Boyd, M. J. Genge
wiley   +1 more source

A more informative way to name plutonic rocks — comment by Frost et al. [PDF]

open access: yes, 2019
Published ...
Anderson, J. Lawford   +4 more
core   +1 more source

Sedimentology of silica granules and haematite in the 3.47 Ga Antarctic Creek Member, Mount Ada Basalt, Western Australia

open access: yesSedimentology, EarlyView.
ABSTRACT The Paleoarchean Antarctic Creek Member of the Mount Ada Basalt, Eastern Pilbara Terrane, Western Australia, includes beds of jasper and white chert composed of sand‐sized silica granules that often contain or are mixed with silt‐sized particles of haematite.
Donald R. Lowe, Gary R. Byerly
wiley   +1 more source

Ductile Extrusion Triggered by Continental Collision in NE Brazil

open access: yesTerra Nova, EarlyView.
ABSTRACT The Borborema Province in northeastern Brazil hosts one of the world's largest strike‐slip shear zone networks, active during the late Neoproterozoic assembly of West Gondwana. Whether these shear zones initiated during active continental collision or as a post‐orogenic response to far‐field stresses remains debated.
L. R. Tesser   +6 more
wiley   +1 more source

Distribution of Fenitized Crustal Xenoliths in Carbonatite Intrusions, West-Central Arkansas [PDF]

open access: yes, 1981
Crustal xenoliths from carbonatite intrusions in the Morrilton-Perryville Arkansas area display a variety of mineralogical and textural features that suggest that they are fragments of basement crystalline rock that has undergone sodic metasomatism ...
Sharp, John
core   +2 more sources

Emergence of Continents Stabilized the Bioavailability of Boron

open access: yesTerra Nova, EarlyView.
ABSTRACT Boron is an essential element for the development of life on Earth; borates stabilize ribose in prebiotic reactions and facilitate metabolism in higher plants. There is, however, a relatively narrow surface boron concentration range over which borates stabilize and serve as a micronutrient rather than a toxin.
Brendan V. Dyck, Jon Wade
wiley   +1 more source

Enhancing Europium Adsorption Effect of Fe on Several Geological Materials by Applying XANES, EXAFS, and Wavelet Transform Techniques

open access: yesToxics
This study conducted adsorption experiments using Europium (Eu(III)) on geological materials collected from Taiwan. Batch tests on argillite, basalt, granite, and biotite showed that argillite and basalt exhibited strong adsorption reactions with Eu.
Chi-Wen Hsieh   +8 more
doaj   +1 more source

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