Results 71 to 80 of about 14,958 (174)

Silicate weathering and carbon cycle controls on the Oligocene-Miocene transition glaciation [PDF]

, 2017
Changes in both silicate weathering rates and organic carbon burial have been proposed as drivers of the transient “Mi-1” glaciation event at the Oligocene-Miocene transition (OMT; ~23 Ma).
Algeo, Anand, Armstrong McKay, Arndt, Baar, Bainbridge, Baker, Barker, Beer, Beer, Bemis, Bemis, Boyle, Boyle, Boyle, Broecker, Burton, Burton, Channell, DeConto, Dekens, Delaney, Delaney, Delaney, Diester-Haass, Florindo, Galy, Garcia, Gasson, Green, Griffith, Hain, Hales, Hall, Hall, Hardie, Harrison, Hathorne, Havach, Henson, Heuser, Hinsbergen, Huh, Joseph A. Stewart, Katz, Kısakűrek, Kroopnick, Lea, Lea, Lear, Lear, Liebrand, Liebrand, Lippert, Locarnini, Lohmann, Lorens, Mangini, Marriott, Marriott, Mashiotta, Mawbey, McArthur, McCorkle, McManus, Meece, Merico, Miller, Misra, Morozov, Oliver, Oxburgh, Oxburgh, Pallavi Anand, Paul, Paul A. Wilson, Pearson, Peucker-Ehrenbrink, Peucker-Ehrenbrink, Pälike, Pälike, Rachael H. James, Ravizza, Raymo, Rickaby, Ripperger, Rosenthal, Rosenthal, Rosenthal, Rowley, Russell, Russell, Russell, Sexton, Shipboard Scientific Party, Smith, Stallard, Stewart, Stewart, Tachikawa, Takahashi, Thomson, Tyson, Veizer, Vigier, Walker, West, Zachos   +107 more
core   +3 more sources

New evidence on the formation conditions of the Libyan Desert Glass (Western Egypt): Clues from a dendritic zircon inclusion

Meteoritics &Planetary Science, EarlyView.
Abstract Libyan Desert Glass (LDG) is an ~29 million years old, silica‐rich glass found in Western Egypt. Whether this glass formed in an impact cratering context associated with the hypervelocity collision of a cometary/asteroidal body or radiative heating during an airburst is debated. Determination of the formation temperatures and pressures of rare
Niccolò Magnani, Enrico Mugnaioli, Sofia Lorenzon, Lidia Pittarello, Tatiana E. Gorelik, Matteo Masotta, Luigi Folco   +6 more
wiley   +1 more source

Growth and reworking of freshwater microbially‐mediated carbonates in wind‐stressed lake margins (Lago Sarmiento, Southern Patagonia)

Sedimentology, EarlyView.
ABSTRACT Understanding the biotic and abiotic influences on the deposition and diagenesis of recent microbial carbonates is crucial for addressing the environmental and ecological significance of ancient organosedimentary structures. This study investigates these factors and their expression in the microstructure of Holocene tufa thrombolites from a ...
Paulo Quezada, Mauricio Calderón, Anelize Bahniuk, Carolina Henríquez, Tatiana Stepanenko, José Pérez‐Donoso, Nicolás Bruna, Larissa Santos, Guilherme Fedalto, Luis Mancini, Leonardo Fadel Cury   +10 more
wiley   +1 more source

Rheological transitions in the middle crust:insights from Cordilleran metamorphic core complexes [PDF]

, 2017
High-strain mylonitic rocks in Cordilleran metamorphic core complexes reflect ductile deformation in the middle crust, but in many examples it is unclear how these mylonites relate to the brittle detachments that overlie them.
Behr, Whitney M., Cooper, Frances J., Platt, John P.   +2 more
core   +3 more sources

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

Terra 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, B. V. Ribeiro, F. Alkmim, A. Deramchi, C. L. Kirkland   +4 more
wiley   +1 more source

⁸⁷Sr/⁸⁶Sr chemostratigraphy of Neoproterozoic Dalradian limestones of Scotland and Ireland: constraints on depositional ages and time scales [PDF]

, 2004
New calcite ⁸⁷Sr/⁸⁶Sr data for 47 limestones from the metamorphosed and deformed Neoproterozoic-Cambrian Dalradian Supergroup of Scotland and Ireland are used to identify secular trends in seawater <sup>
Ellam, R.M., Fallick, A.E., Graham, C.M., Thomas, C.W.   +3 more
core   +1 more source

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

Terra 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

Granitic rocks and metasediments in Archean crust, Rainy Lake area, Ontario: ND isotope evidence for mantle-like SM/ND sources [PDF]

Granitoids, felsic volcanic rocks and clastic metasediments are typical rocks in Archean granite-greenstone belts that could have formed from preexisting continentasl crust.
Hanson, G. N., Shirey, S. B.
core   +1 more source

Subcritical Cracking Associated With Subgrain Rotation Recrystallisation in Quartz Inferred From Cathodoluminescence Study

Terra Nova, EarlyView.
ABSTRACT We employed cathodoluminescence (CL) to study deformed quartz phenocrysts from the Cretaceous granite porphyry in SW Japan and observed fracture‐like planar structures appearing as CL‐dark bands. These CL‐dark bands were aligned with low‐angle grain boundaries formed by subgrain rotation recrystallisation.
Takuro Yoshioka, Takamoto Okudaira, Hideo Takagi   +2 more
wiley   +1 more source

Fluorination of Silver Phosphate in Nickel Reaction Vessels for Triple Oxygen Isotope Analysis

Rapid Communications in Mass Spectrometry, Volume 40, Issue 7, 15 April 2026.
ABSTRACT Rationale Increasingly, more laboratories are measuring the triple oxygen isotope values of phosphate. Standardization is key to having good interlaboratory results. Here, we present the triple oxygen isotope values of a suite of standards using fluorination and compare them with previously reported triple oxygen isotope values. Methods Silver
Jordan A. G. Wostbrock, Drake Yarian, Isabella Chiaravalloti, Spencer R. Moller, Ruth E. Blake   +4 more
wiley   +1 more source