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Abstract-This study provides a complete data set of all five noble gases for bulk samples and mineral separates from three Martian shergottites: Shergotty (bulk, pyroxene, maskelynite), Zagami (bulk, pyroxene, maskelynite), and Elephant Moraine (EET) A79001, lithology A (bulk, pyroxene). We also give a compilation of all noble gas and nitrogen studies performed on these meteorites. Our mean values for cosmic-ray exposure ages from 3 He, 21 Ne, and 38 Ar are 2.48 Myr for Shergotty, 2.73 Myr for Zagami, and 0.65 Myr for EETA79001 lith. A. Serious loss of radiogenic 4 He due to shock is observed. Cosmogenic neon results for bulk samples from 13 Martian meteorites (new data and literature data) are used in addition to the mineral separates of this study in a new approach to explore evidence of solar cosmic-ray effects. While a contribution of this low-energy irradiation is strongly indicated for all of the shergottites, spallation Ne in Chassigny, Allan Hills (ALH) 84001, and the nakhlites is fully explained by galactic cosmic-ray spallation. Implanted Martian atmospheric gases are present in all mineral separates and the thermal release indicates a near-surface siting. We derive an estimate for the 40 Ar/ 36 Ar ratio of the Martian interior component by subtracting from measured Ar in the (K-poor) pyroxenes the (small) radiogenic component as well as the implanted atmospheric component as indicated from 129 Xe * excesses. Unless compromised by the presence of additional components, a high ratio of ~2000 is indicated for Martian interior argon, similar to that in the Martian atmosphere. Since much lower ratios have been inferred for Chassigny and ALH 84001, the result may indicate spatial and/or temporal variations of 40 Ar/ 36 Ar in the Martian mantle.

It is known that the presence of background magnetic field in cosmic plasma distorts the acoustic peaks in CMBR. This primarily results from different types of waves in the plasma with velocities depending on the angle between the magnetic field and the wave vector. We consider the consequences of these effects in relativistic heavy-ion collisions where very strong magnetic fields arise during early stages of the plasma evolution. We show that flow coefficients can be significantly affected by these effects when the magnetic field remains strong during early stages due to strong induced fields in the conducting plasma. In particular, the presence of magnetic field can lead to enhancement in the elliptic flow coefficient v2.PACS numbers: 52.35. Bj, 25.75.Ld, 12.38.Mh It has been recently shown by us that a deep correspondence exists between the physics of inflationary density fluctuations in the early universe which result in the CMBR acoustic peaks and the physics of flow in relativistic heavy-ion collision experiments (RHICE) [1]. We further showed that important features such as acoustic peaks and suppression of superhorizon fluctuations may be present in a plot of root-mean square values of flow coefficients v . This non-trivial connection between the superhorizon fluctuations of inflationary universe and similar fluctuations in RHICE is now discussed in several works and its various consequences are explored (see, e.g. [4]). We mention that such a connection between physics of RHICE and that of inflationary universe was never anticipated earlier, and indeed, at first sight, it looks surprising that a concept like superhorizon fluctuation which arises from highly non-trivial, superluminal expansion phase of the very early universe could have any relevance for relativistic heavyion collision experiments in laboratory. Such superhorizon fluctuations in RHICE originate from the fact that in the center of mass frame the thermalization (and any local homogenization) happens rather quickly, within about 1 fm. Initial parton energy density distribution from HIJING shows that transverse fluctuations (arising from localization of partons inside initial nucleons, and from the fluctuations in nucleon coordinates) with wavelengths significantly larger than 1 fm are necessarily present at the time 1 fm even in central collisions.It was also emphasized in [1] that various analysis tools of CMBR anisotropies can be effectively utilized for RHICE. It was proposed in [1] that instead of focusing on the average values of the flow coefficients v n for small values of n [5], one should calculate root-mean square values of the flow coefficients v rms n for a large range of n upto 30-40. Further, these calculations should be performed in a lab fixed frame, which eliminates the difficulties associated with determination of event plane for conventional elliptic flow analysis for non-central collisions. It was shown in [1] that a plot of values of v rms n vs. n can be used for directly probing various flow coefficients, in particu...

Diamond grains are the most abundant presolar grains found in primitive meteorites. They formed before the Solar System, and therefore provide a record of nuclear and chemical processes in stars and in the interstellar medium. Their origins are inferred from the unusual isotopic compositions of trace elements-mainly xenon-which suggest that they came from supernovae. But the exact nature of the sources has been enigmatic, as has the method by which noble gases were incorporated into the grains. One observation is that different isotopic components are released at different temperatures when the grains are heated, and it has been suggested that these components have different origins. Here we report results of a laboratory study that shows that ion implantation (previously suggested on other grounds) is a viable mechanism for trapping noble gases. Moreover, we find that ion implantation of a single isotopic composition can produce both low- and high-temperature release peaks from the same grains. We conclude that both isotopically normal and anomalous gases may have been implanted by multiple events separated in space and/or time, with thermal processing producing an apparent enrichment of the anomalous component in the high-temperature release peak. The previous assumption that the low- and high-temperature components were not correlated may therefore have led to an overestimate of the abundance of anomalous argon and krypton, while obscuring an enhancement of the light-in addition to the heavy-krypton isotopes.

Consideration of the geosphere for isolation of nuclear waste has generated substantial interest in the origin, age, and movement of fl uids and gases in low-permeability rock formations. Here, we present profi les of isotopes, solutes, and helium in porewaters recovered from 860 m of Cambrian to Devonian strata on the eastern fl ank of the Michigan Basin. Of particular interest is a 240-m-thick, halite-mineralized, Ordovician shale and carbonate aquiclude, which hosts Br --enriched, post-dolomitic brine (5.8 molal Cl) originating as evaporated Silurian seawater. Authigenic helium that has been accumulating in the aquiclude for more than 260 m.y. is found to be isolated from underlying allochthonous, 3 He-enriched helium that originated from the rifted base of the Michigan Basin and the Canadian Shield. The Paleozoic age and immobility of the pore fl uids in this Ordovician aquiclude considerably strengthen the safety case for deep geological repositories, but also provide new insights into the origin of deep crustal brines and opportunities for research on other components of a preserved Paleozoic porewater system.