A billion-year shift in the formation of Earth's largest ore deposits.

Banded iron formations (BIFs) archive the relationship between Earth's lithosphere, hydrosphere, and atmosphere through time. However, constraints on the origin of Earth's largest ore deposits, hosted by BIFs, are limited by the absence of direct geochronology. Without this temporal context, genetic models cannot be correlated with tectono-thermal and atmospheric drivers responsible for BIF upgrading through time. Utilizing in situ iron oxide U-Pb geochronology, we provide a direct timeline of events tracing development of all the giant BIF-hosted hematite deposits of the Hamersley Province (Pilbara Craton, Western Australia). Direct dating demonstrates that the major iron ore deposits in the region formed during 1.4 to 1.1 Ga. This is one billion to hundreds of millions of years later than previous age constraints based upon 1) the presence of hematite ore clasts in conglomerate beds deposited before ~1.84 Ga, and 2) phosphate mineral dating, which placed the onset of iron mineralization in the Province at ~2.2 to 2.0 Ga during the great oxidation event. Dating of the hematite clasts verified the occurrence of a ~2.2 to 2.0 Ga event, reflecting widespread, but now largely eroded iron mineralization occurring when the Pilbara and Kaapvaal cratons were proximal. No existing phosphate mineral dates overlap with obtained hematite dates and therefore cannot be related to hematite crystallization and ore formation. New geochronology conclusively links all major preserved hematite deposits to a far younger (1.4 to 1.1 Ga) formation period, correlated with the amalgamation of Australia following breakup of the Columbia supercontinent.

Increasing pension age - Inevitable or unfeasible? Analysing the ideas underlying experts' arguments in the UK and Germany.

Based on interviews with German and British experts from major political parties, government departments, employer confederations, trade unions and special interest organisations, we investigate the chains of arguments that these experts advance in favour of or against increases in state pension age. In this way, we add to the explanation why very similar reforms could be enforced in the very different pension systems of Germany and the UK. The chains of arguments deployed are surprisingly similar between the two countries: Whereas the proponents of reform stress its necessity in the context of pension spending and see older people as being able to work longer, opponents and sceptics of the increase doubt most older people's ability to work longer and thus the feasibility of the reform. The proponents prioritise ideas of intergenerational justice and meritocratic justice based on individual performance, and underline pension-related interest oppositions between age groups and cohorts. By contrast, opponents and sceptics tend to focus on needs-based justice and social inequalities within age groups. Concomitantly, the actors have different ideas on how a flexible transition to retirement could be organised, with country differences being more pronounced here.