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| Zimmerman, Susan H.; Hemming, Sidney R.; Kent, Dennis V.; Searle, Stephanie Y.. |
| Lakes are highly sensitive recorders of climate processes, but are extremely difficult to correlate precisely to ice-core and marine records, especially in the absence of reliable radiocarbon dates. Relative paleointensity (RPI) of Earth's magnetic field is an independent method of correlating high-resolution climate records, and can be applied to both marine and terrestrial sediments, as well as (inversely) correlated to the cosmogenic nuclide records preserved in ice cores. Here we present the correlation of an RPI record from Mono Lake, California to GLOPIS, the Global PaleoIntensity Stack, which increases the age estimation of the basal Mono Lake sediments by > 20000 yr (20 kyr), from similar to 40 ka (kyr before present) to 67 ka. The Mono Lake... |
| Tipo: Text |
Palavras-chave: Paleointensity; GLOPIS; Argon; Great Basin; Mono Lake excursion; Laschamp. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34500/33454.pdf |
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| Peron, Sandrine; Moreira, Manuel; Agranier, Arnaud. |
| We review the different scenarios for the origin of light noble gases (He, Ne, and Ar) on Earth. Several sources could have contributed to the Earth's noble gas budget: implanted solar wind, solar nebula gas, chondrites, and comets. Although there is evidence for solar-like neon in the Earth's mantle, questions remain as to its origin. A new compilation of noble gas data in lunar soils, interplanetary dust particles, micrometeorites, and solar wind allows examination of the implanted solar wind composition, which is key to understanding the solar-like mantle neon isotope composition. We show that lunar soils that reflect this solar-wind-implanted signature have a Ne-20/Ne-22 ratio very close to that of ocean island basalts. New data and calculations... |
| Tipo: Text |
Palavras-chave: Volatile origin; Helium; Neon; Argon; Solar wind implantation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00638/74992/75837.pdf |
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| Mollex, Gaelle; Furi, Evelyn; Burnard, Pete; Zimmermann, Laurent; Chazot, Gilles; Kazimoto, Emmanuel O.; Marty, Bernard; France, Lyderic. |
| Oldoinyo Lengai is the only volcano on Earth currently erupting natrocarbonatites, of which the source and genesis remain controversial. Cognate xenoliths and fumaroles were sampled at the summit of Oldoinyo Lengai, and deep crustal xenoliths from Oltatwa maar, in 2010 and 2014, after the 2007-2008 sub-Plinian eruption. The summit cognate xenoliths provide direct information on the isotopic composition of the mid-crustal magma chamber that was active during the 2007-2008 explosive eruption. Cognate xenolith-hosted pyroxenes from Oldoinyo Lengai have an average He-3/He-4 = 6.58 +/- 0.46 R-A, similar to values from nearby silicate volcanoes (4.95-7.30 R-A), and reflecting a sub-continental lithospheric mantle (SCLM) signature. This similarity implies that... |
| Tipo: Text |
Palavras-chave: Carbonatite; Neon; 2007-2008 eruption; SCLM; Cognate xenoliths; Helium; Neon; Argon. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00638/74994/75820.pdf |
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