A crustal Pb isotope map of southeastern Australia.

Lead isotopes are a powerful geochemical tracer and a popular tool applied across a broad range of scientific fields, e.g., earth sciences, archaeology, and forensic sciences.

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.

Nd isotope variation between the Earth-Moon system and enstatite chondrites.

Reconstructing the building blocks that made Earth and the Moon is critical to constrain their formation and compositional evolution to the present. Neodymium (Nd) isotopes identify these building blocks by fingerprinting nucleosynthetic components. In addition, the Sm-Nd and Sm-Nd decay systems, with half-lives of 103 million years and 108 billion years, respectively, track potential differences in their samarium (Sm)/Nd ratios.

Multivariate analysis of otolith microchemistry can discriminate the source of oil contamination in exposed fish.

The uptake of metals into the aragonite lattice of the fish otolith (ear-bone) has been used for decades as a historical record of exposure to metals in polluted environments. The relative abundance of two metals in particular, Ni and V, are used in forensic chemical analysis of crude oils to assist in confirming its origin. In this study we investigate the potential for metal accumulation in otoliths to act as a biomarker of exposure to crude oil.

Snake scales record environmental metal(loid) contamination.

Wetland snakes, as top predators, are becoming globally recognised as bioindicators of wetland contamination. Livers are the traditional test organ for contaminant exposure in organisms, but research is moving towards a preference for non-lethal tissue sampling. Snake scales can be used as an indicator of exposure, as many metals bind to the keratin.

Coral record of southeast Indian Ocean marine heatwaves with intensified Western Pacific temperature gradient.

Increasing intensity of marine heatwaves has caused widespread mass coral bleaching events, threatening the integrity and functional diversity of coral reefs. Here we demonstrate the role of inter-ocean coupling in amplifying thermal stress on reefs in the poorly studied southeast Indian Ocean (SEIO), through a robust 215-year (1795-2010) geochemical coral proxy sea surface temperature (SST) record. We show that marine heatwaves affecting the SEIO are linked to the behaviour of the Western Pacific Warm Pool on decadal to centennial timescales, and are most pronounced when an anomalously strong zonal SST gradient between the western and central Pacific co-occurs with strong La Niña's.

Rapid, high-precision measurements of boron isotopic compositions in marine carbonates.

Rationale: The isotopic composition and elemental abundance of boron (B) in marine carbonates provide a powerful tool for tracking changes in seawater pH and carbonate chemistry. Progress in this field has, however, been hampered by the volatile nature of B, its persistent memory, and other uncertainties associated with conventional chemical extraction and mass spectrometric measurements. Here we show that for marine carbonates, these limitations can be overcome by using a simplified, low-blank, chemical extraction technique combined with robust multi-collector inductively couple plasma mass spectrometry (MC-ICPMS) methods.

Corals record long-term Leeuwin current variability including Ningaloo Niño/Niña since 1795.

Variability of the Leeuwin current (LC) off Western Australia is a footprint of interannual and decadal climate variations in the tropical Indo-Pacific. La Niña events often result in a strengthened LC, high coastal sea levels and unusually warm sea surface temperatures (SSTs), termed Ningaloo Niño. The rarity of such extreme events and the response of the southeastern Indian Ocean to regional and remote climate forcing are poorly understood owing to the lack of long-term records.

Neodymium isotope evidence for a chondritic composition of the Moon.

Samarium-neodymium isotope data for six lunar basalts show that the bulk Moon has a 142Nd/144Nd ratio that is indistinguishable from that of chondritic meteorites but is 20 parts per million less than most samples from Earth. The Sm/Nd formation interval of the lunar mantle from these data is 215(-21)(+23) million years after the onset of solar system condensation. Because both Earth and the Moon likely formed in the same region of the solar nebula, Earth should also have a chondritic bulk composition.