A Short Duration of the Cretaceous-Tertiary Boundary Event …
9 MARCH 2001 VOL 291 SCIENCE A Short Duration of the Cretaceous-Tertiary Boundary Event: Evidence from Extraterrestrial Helium-3 S. …Web
اقرأ أكثرThe chemistry of the extraterrestrial carbonaceous stone …
An extraterrestrial origin for a carbonaceous, diamond-bearing and silicate-free stone named "Hypatia", found in 1996 in southwest Egypt, was determined in 2013 and confirmed in 2015 on the basis of argon, helium, neon, …Web
اقرأ أكثرPenn Chemical Engineering -- Alan Myers
A.L. Myers and F. Siperstein, "Characterization of adsorbents by energy profile of adsorbed molecules", Colloids and Surfaces A 187-188, 73-81 (2001). Article [PDF] O. Talu and A.L. Myers, "Molecular simulation of adsorption: Gibbs dividing surface and comparison with experiment", AIChE J. 47, 1160-1168 (2001).Web
اقرأ أكثرPreservation of extraterrestrial 3He in 480-Ma-old marine …
DOI: 10.1016/S0012-821X(98)00197-6 Corpus ID: 24720909; Preservation of extraterrestrial 3He in 480-Ma-old marine limestones. @article{Patterson1998PreservationOE, title={Preservation of extraterrestrial 3He in 480-Ma-old marine limestones.}, author={Desmond B. Patterson and Kenneth A. Farley and …Web
اقرأ أكثرAn extraterrestrial 3He-based timescale for the …
1.. IntroductionThe gradual warming trend of the early Cenozoic hothouse world is punctuated by several transient extreme global warming events (Zachos et al., 2001, Lourens et al., 2005, Quillévéré et al., 2008) that can serve as examples of the climate system response to rapid greenhouse warming.The most prominent and well studied of …Web
اقرأ أكثرAn Extraterrestrial Impact at the Permian-Triassic Boundary?
The helium we obtained from Bed 25 samples is reasonable for a 250-million-year-old volcanic ash bed. Large inter-aliquot variability in 4 He content and the survival of most 4 He through HF demineralization suggest that accessory zircons, known to exist in Bed 25 (), control the distribution of this isotope.The 3 He concentration and 3 …Web
اقرأ أكثرGould's Belt, interstellar clouds, and the Eocene–Oligocene helium …
It seems reasonable to suppose that, if Bekki's scenario is correct, the dark matter blob and/or the cloud may be linked to the temporary factor of ∼2 increase in the influx of extraterrestrial 3 He (helium-3) seen in the sedimentary record 36–34 × 10 6 y ago (Farley et al., 1998, Farley, 2001, Mukhopadhyay et al., 2001), as well as to ...Web
اقرأ أكثرThe Rise and Fall of Dino World
Washington - Feb. 22, 2001 - New findings provide evidence that Earth's most severe mass extinction -- an event 250 million years ago that wiped out 90 percent of the life on Earth …Web
اقرأ أكثرExtraterrestrial 3He in Paleocene sediments from Shatsky Rise
Sediments contain interplanetary dust particles (IDPs) carrying extraterrestrial noble gases, such as 3 He, which have previously been used to estimate the IDP accretion flux over time and the duration of past environmental events. However, due to its high diffusivity, He can be lost by diffusion either due to frictional heating during …Web
اقرأ أكثر(PDF) A Short Duration of the Cretaceous-Tertiary Boundary …
Analyses of marine carbonates through the interval 63.9 to 65.4 million years ago indicate a near-constant flux of extraterrestrial helium-3, a tracer of the accretion …Web
اقرأ أكثرAn Extraterrestrial Impact at the Permian-Triassic Boundary?
Since the helium and argon found in PTB fullerenes were isotopically similar to that found in meteorites, Becker et al. (2001) suggested that the fullerenes must have come from a meteorite.Web
اقرأ أكثرRapid recovery of life at ground zero of the end-Cretaceous mass
Mukhopadhyay, S., Farley, K. A. & Montanari, A. A short duration of the Cretaceous-Tertiary boundary event: evidence from extraterrestrial helium-3. Science …Web
اقرأ أكثرEarth's Thermostat Went Awry, and the Air Grew Thin
In 2001, Dr. Becker and her colleagues said they had found the calling card of a killer meteor: soccer- ball-shaped molecules known as buckyballs that contained helium with an extraterrestrial ...Web
اقرأ أكثرImpact event at the Permian-Triassic boundary: evidence from
Recent studies of some PTB sites indicate that the extinctions occurred very abruptly, consistent with a catastrophic, possibly extraterrestrial, cause. Fullerenes …Web
اقرأ أكثرAsteroid or Comet Triggered Largest Mass Extinction in Earth's …
February 22, 2001 . Filed under ... Terrestrial helium is mostly helium-4, while extraterrestrial helium is mostly helium-3. "These things form in carbon stars. That's what's excitingWeb
اقرأ أكثرAbsence of extraterrestrial He-3 in Permian-Triassic age sedimentary
Previous reports of shocked quartz grains and extraterrestrial helium and argon trapped in fullerene molecules have not been substantiated (Farley and Mukhopadhyay, 2001; Farley et al., 2005 ...Web
اقرأ أكثرExtraterrestrial Helium in Seafloor Sediments: Identification
Almost 40 years after the discovery of extraterrestrial helium in seafloor sediments, renewed attention is being focused on using helium as a proxy for the sedimentary abundance of extraterrestrial debris. Extraterrestrial He is carried to the seafloor by the finest fraction of interplanetary dust and is retained in at least some sediments for …Web
اقرأ أكثرHelium isotopes in ferromanganese crusts from the
Helium isotopes have been measured in samples of two ferromanganese crusts (VA13/2 and CD29-2) from the central Pacific Ocean. With the exception of the deepest part of crust CD29-2 the data can be explained by a mixture of implanted solar- and galactic cosmic ray-produced (GCR) He, in extraterrestrial grains, and radiogenic He in …Web
اقرأ أكثرThe Younger Dryas impact hypothesis: a critical review
Fullerenes with extraterrestrial helium on the other hand, are considered controversial and have not been confirmed independently at any known impact site ... However, when compared to the spectra published by Konyashin et al. (2001, Fig. 3), the spectrum in Kurbatov et al. ...Web
اقرأ أكثرA Short Duration of the Cretaceous-Tertiary Boundary Event
Assuming reasonable end-member 3 He/ 4 He ratios of 0.03R A and 290 R A (19, 20) for the crustal and extraterrestrial components, the calculated [3 He] Et is >86% of the total 3 He. Helium-4 ([4 He]) is >99% terrestrial and may therefore be used as a tracer of the relative terrigenous flux .Web
اقرأ أكثرImpact Event at the Permian-Triassic Boundary: Evidence from
The accretion of extraterrestrial noble gases such as He and Ar was discussed by Becker et al. (2001), who reported high concentrations of extraterrestrial He ( 3 He ET ) in PTB rocks from Japan ...Web
اقرأ أكثرSubduction of solar-type noble gases from extraterrestrial dust
Solar-type helium (He) and neon (Ne) in the Earth's mantle were suggested to be the result of solar-wind loaded extraterrestrial dust that accumulated in deep-sea sediments and was subducted into the Earth's mantle. To obtain additional constraints on this hypothesis, we analysed He, Ne and argon (Ar) in high pressure–low temperature …Web
اقرأ أكثرGeochemical Background and Methodology 1. Helium …
terr = helium isotope ratio of terrestrial material = 3 x 10-8 [Mamyrin and Tolstikhin, 1984; Farley, 2001]. Between 70 and 230 mg of freeze-dried hand-crushed bulk sediment was wrapped in aluminum foil cups and loaded into the vacuum furnace of the gas inlet system, and analyzed for helium isotopes on a MAP 215-50 massWeb
اقرأ أكثرImpact Event at the Permian-Triassic Boundary: Evidence from
Recent studies of some PTB sites indicate that the extinctions occurred very abruptly, consistent with a catastrophic, possibly extraterrestrial, cause. Fullerenes (C 60 to C …Web
اقرأ أكثرAn extraterrestrial 3He-based timescale for the …
The upper Farley K. A. (2001) Extraterrestrial helium in seafloor sediments: bound of this interval may record the effective end of the identification, characteristics, and accretion rate over geologic PETM perturbation to marine carbonate chemistry.Web
اقرأ أكثرBecker et al. 2001
Recent studies of some PTB sites indicate that the extinction occurred very abruptly, consistent with a catastrophic, possibly extraterrestrial, cause. Fullerenes (C …Web
اقرأ أكثرOn the fluxes and fates of 3He accreted by the Earth with
Extraterrestrial helium (He et) in ferromanganese crusts from the deep oceans is presumed to originate in micrometeorites. ... Pepin et al., 2000, 2001; Lal and Jull, 2005). These end member compositions largely overlap with those estimated here for HRPs and IDPs, inhibiting a quantitative estimate of these fractions in the currently discussed ...Web
اقرأ أكثر(PDF) Extraterrestrial He in Sediments: From Recorder of …
Jan 2001; Kenneth A. Farley; Almost 40 years after the discovery of extraterrestrial helium in seafloor sediments, renewed attention is being focused on using helium as a proxy for the sedimentary ...Web
اقرأ أكثرAsteroid Or Comet Triggered Death Of Most Species 250
February 23, 2001 Source: University Of Washington ... For instance, terrestrial helium is mostly helium-4 and contains only a small amount of helium-3, while extraterrestrial helium - the kind ...Web
اقرأ أكثرFullerenes: An extraterrestrial carbon carrier phase for noble gases
clear extraterrestrial helium signal with. 3. He ... resembling the lunar monolith from 2001: A Space Odyssey [326] and waiting to be discovered. If so, this would be yet another evidence of the ...Web
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