The carbonate phase of impure sideritic concretions from a sequence of argillaceous sediments from the Westphalian of Yorkshire has been analysed using an acid-dissolution technique and corrections allowing for the decomposition of non-carbonate minerals applied to obtain accurate compositional formulae. The siderites show considerable compositional variation, some containing Ca in excess of an...

[1] The Noachian terrain west of the Isidis basin hosts a diverse collection of alteration minerals in rocks comprising varied geomorphic units within a 100,000 km region in and near the Nili Fossae. Prior investigations in this region by the Observatoire pour l’Minéralogie, l’Eau, les Glaces, et l’Activité (OMEGA) instrument on Mars Express revealed large exposures of both mafic minerals and i...

in this study, the reliability of the primary gold mineralization exploration using multispectral etm+ imagery was investigated in lahroud region, northwest iran, which was conducted by integration of alteration and structural indicators. co-occurrence of the clay minerals and iron oxides is an important criterion in gold deposit exploration; therefore, their alteration zones were mapped using ...

We perform collisionlessN -body simulations of 1:1 galaxy mergers, using models which include a galaxy halo, disc and bulge, focusing on the behaviour of the halo component. The galaxy models are constructed without recourse to a Maxwellian approximation. We investigate the effect of varying the galaxies’ orientation, their mutual orbit, and the initial velocity anisotropy or cusp strength of t...

A myopathy with severe exercise intolerance and myoglobinuria has been described in patients from northern Sweden, with associated deficiencies of succinate dehydrogenase and aconitase in skeletal muscle. We identified the gene for the iron-sulfur cluster scaffold protein ISCU as a candidate within a region of shared homozygosity among patients with this disease. We found a single mutation in I...

This research compared the influence of (1) dissolution of iron oxides and (2) alteration of electrostatic interactions on the mobilization of colloids in a clayand iron oxidecoated sand obtained from an Atlantic Coastal Plain aquifer in which colloids have been found suspended only in anoxic groundwater. The sediment was flushed with solutions of varying ionic strength, pH, and reductant and s...

Using stacks of Lyα images of 2128 Lyα emitters (LAEs) and 24 protocluster UVselected galaxies (LBGs) at z = 3.1, we examine the surface brightness profiles of Lyα haloes around high-z galaxies as a function of environment and UV luminosity. We find that the slopes of the Lyα radial profiles become flatter as the Mpc-scale LAE surface densities increase, but they are almost independent of the c...

Recent research on BIF-related high-grade iron ore mineralization has resulted in new genetic models that emphasize the structurally controlled hypogene alteration and upgrade of BIF to high-grade (>65% Fe) iron ore. Conventional structural and stratigraphic mapping and reconstructions of the tectonic history of iron districts, in combination with high-tech geochemical analyses such as laser IC...

We uncover the origin of the puzzling anti-correlation between the formation epoch of galactic dark-matter haloes and their environment density. This correlation has been revealed from cosmological N -body simulations and it is in conflict with the simple excursion-set model of halo clustering. Using similar simulations, we first quantify the straightforward association of an early formation ep...

Observations reveal that quasar host haloes at z ∼ 2 have large covering fractions of cool dense gas ( 60 per cent for Lyman limit systems within a projected virial radius). Most simulations have so far failed to explain these large observed covering fractions. We analyse a new set of 15 simulated massive haloes with explicit stellar feedback from the FIRE project, covering the halo mass range ...