New age data on the geological evolution of Southern India

The Peninsular Gneisses of Southern India developed over a period of several hundred Ma in the middle-to-late Archaean. Gneisses in the Gorur-Hassan area of southern Karnataka are the oldest recognized constituents: Beckinsale et al. reported a preliminary Rb-Sr whole-rock isochron age of 33558 + or - 66 Ma, but further Rb-Sr and Pb/Pb whole-rock isochron determinations indicate a slightly younger, though more precise age of ca 3305 Ma (R. D. Beckinsale, Pers. Comm.). It is well established that the Peninsular Gneisses constitute basement on which the Dharwar schist belts were deposited. Well-documented exposures of unconformities, with basal quartz pebble conglomerates of the Dharwar Supergroup overlying Peninsular Gneisses, have been reported from the Chikmagalur and Chitradurga areas, and basement gneisses in these two areas have been dated by Rb-Sr and Pb/Pb whole-rock isochron methods at ca 3150 Ma and ca 3000 Ma respectively. Dharwar supracrustal rocks of the Chitradurga schist belt are intruded by the Chitradurga Granite, dated by a Pb/Pb whole-rock isochron at 2605 + or - 18 Ma. These results indicate that the Dharwar Supergroup in the Chitradurga belt was deposited between 3000 Ma and 2600 Ma

Critical review of the impacts of grazing intensity on soil organic carbon storage and other soil quality indicators in extensively managed grasslands

Acknowledgements This work contributes to the N-Circle project (grant number BB/N013484/1), and CINAg (BB/N013468/1) Virtual Joint Centres on Agricultural Nitrogen (funded by the Newton Fund via UK BBSRC/NERC), U-GRASS (grant number NE/M016900/1), the Belmont Forum/FACCE-JPI DEVIL project (grant number NE/M021327/1), Soils-R-GGREAT (grant number NE/P019455/1), ADVENT (grant number NE/M019713/1), Sêr Cymru LCEE-NRN project, Climate-Smart Grass and the Scottish Government’s Strategic Research Programme.Peer reviewedPublisher PD

A search for Centaurus A-like features in the spectra of Fermi-LAT detected radio galaxies

Motivated by the detection of a hardening in the γ-ray spectrum of the radio galaxy CentaurusA, we have analysed ∼10 years of Fermi-LAT observations of 26 radio galaxies to search for similar spectral features. We find that the majority of the radio galaxies’ γ-ray spectral energy distributions are best fitted with a simple power-law model, and no spectral hardening similar to that found in CentaurusA was detected. We show that, had there been any such spectral features present in our sample of radio galaxies, they would have been seen, but note that 7 of the radio galaxies (3C111, 3C120, 3C264, IC4516, NGC1218, NGC2892 and PKS0625-35) show evidence for flux variability on 6-month timescales, which makes the detection of any steady spectral features difficult. We find a strong positive correlation (r = 0.9) between the core radio power at 5GHz and the γ-ray luminosity and, using a simple extrapolation to TeV energies, we expect around half of the radio galaxies studied will be detectable with the forthcoming Cherenkov Telescope Array

7-Li(p,n) Nuclear Data Library for Incident Proton Energies to 150 MeV

We describe evaluation methods that make use of experimental data, and nuclear model calculations, to develop an ENDF-formatted data library for the reaction p + Li7 for incident protons with energies up to 150 MeV. The important 7-Li(p,n_0) and 7-Li(p,n_1) reactions are evaluated from the experimental data, with their angular distributions represented using Lengendre polynomial expansions. The decay of the remaining reaction flux is estimated from GNASH nuclear model calculations. The evaluated ENDF-data are described in detail, and illustrated in numerous figures. We also illustrate the use of these data in a representative application by a radiation transport simulation with the code MCNPX.Comment: 11 pages, 8 figures, LaTeX, submitted to Proc. 2000 ANS/ENS International Meeting, Nuclear Applications of Accelerator Technology (AccApp00), November 12-16, Washington, DC, US