This work presents novel advances in the estimation of open biomass burning emissions via the first fully "top-down" approach to exploit satellite-derived observations of fire radiative power and carbon monoxide over Africa. We produce a 16-year record of fire-generated CO emissions and dry matter consumed per unit area for Africa and evaluate these emissions estimates through their use in an atmospheric model, whose simulation output is then compared to independent satellite observations of CO.

The Great Unconformity represents an enormous amount of time lost from the sedimentary record. Its origin is debated, in part, due to different approaches used to interpret zircon (U–Th)/He ages. This thermochronometric system is ideal for this problem because the temperature sensitivity varies according to radiation damage. Here we explore the uncertainty associated with the radiation damage model and show how this limits our ability to resolve the origin of the Great Unconformity.

Secondary ion mass spectrometry (SIMS) is the oldest and most sensitive analytical technique for in situ U–Pb geochronology. This paper introduces a new algorithm for SIMS data reduction that treats data as compositional data, which means that the relative abundances of ²⁰⁴Pb, ²⁰⁶Pb, ²⁰⁷Pb, and ²³⁸Pb are processed within a tetrahedral data space or simplex. The new method is implemented in an eponymous computer programme that is compatible with the two dominant types of SIMS instruments.

A conventional isochron is a straight-line fit to two sets of isotopic ratios, D/d and P/d, where P is the radioactive parent, D is the radiogenic daughter, and d is a second isotope of the daughter element. The slope of this line is proportional to the age of the system. An inverse isochron is a linear fit through d/D and P/D. The horizontal intercept of this line is inversely proportional to the age. The latter approach is preferred when d<D, which is the case in Re–Os and K–Ca geochronology.

This paper shows that the current practice of filtering discordant U–Pb data based on the relative difference between the ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²⁰⁶Pb ages is just one of several possible approaches to the problem and demonstrably not the best one. An alternative approach is to define discordance in terms of isotopic composition, as a log ratio distance between the measurement and the concordia line. Application to real data indicates that this reduces the positive bias of filtered age spectra.