We study the sensitivity of multi ton-scale time projection chambers using a liquid xenon target, e.g., the proposed DARWIN instrument, to spin-independent and spin-dependent WIMP-nucleon scattering interactions.
Samples analysed in this study are from a core (BARB 3) drilled in the BGB, South Africa. This excess argon component is correlated with the chlorine (Cl) content (Figs 1 and 2) and probably reflects enrichment of the fluids in crustal-derived radiogenic argon and chlorine during fluid-rock interaction processes before entrapment.
The drilling project is part of an ICDP Project (‘Peering into the cradle of life’, PI: N. The BARB 3 core was drilled in rocks of the Kromberg formation (3.33–3.47 Ga) and mainly comprises a succession of white and black cherts and ultramafic rocks. 1b) contacts with adjacent white chert; other samples are from meter-sized coarse quartz veins. Only step-heating steps yielding elevated K/Cl ratios give realistic ages between 3 and 3.5 Ga that are broadly compatible with the age of the formations in which the quartz veins are emplaced (Fig. We correct 3) apparent ages decrease towards more realistic values between 3 and 3.5 Ga (purple range).
Furthermore, Archean Xe originates from a primordial component different from all other known reservoirs of Xe in the solar system and similar to the theoretical U-Xe.
Comets may have been the source of this noble gas component, added to the Earth's atmosphere during late accretionary events.
Here we demonstrate that fluid inclusions in the Barberton quartz samples record the Xe isotope composition of the Archean atmosphere.
This 3.3 Ga-old atmospheric Xe is mass-dependently fractionated by ≈13 ‰ u Xe relative to the modern atmosphere allows us to compute a degassing rate from the Earth's mantle to the atmosphere over the last 3.3 Ga.
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No error is given for the fractionation described in ref. that the peculiar Xe isotopic composition during the Archean eon was ubiquitous and not due to local fractionation effects.
The results provide confirmation for the specific and long-term evolution of the isotopic composition of atmospheric Xe, since the fractionation determined here is significantly different from 21±6 ‰ u (Fig. A mass-dependent isotope fractionation process acted on atmospheric Xe isotopes from at least 3.3 Ga until the present day.
The reproducibility of the crushing experiment results (Supplementary Table 2) on different samples and duplicates (Methods and Supplementary Fig.