The LGC is recruiting a programmer

The LGC is looking for a software developer to help us improve geochronological data processing.

The 'Beyond Isoplot' project aims to create a 'software revolution' in geochronology, by building an internally consistent ecosystem of computer programs to account for inter-sample error correlations. These have a first order effect on the precision and accuracy of geochronology but are largely ignored by current geochronological data processing protocols. The proposed software will modify existing data reduction platforms and create entirely new ones. It will implement a data exchange format to combine datasets from multiple chronometers together whilst keeping track of the correlated uncertainties between them.

The new algorithms will be applied to five important geological problems, namely (1) the age of the Solar System; (2) the timing of the Cretaceous-Palaeogene mass extinction event that wiped out the dinosaurs; (3) the age of the famous Taung Child hominin fossil; (4) the formation and cooling history of the Earth's crust; and (5) noble gas diffusion in silicate minerals and rocks. These applications demonstrate the far-reaching implications of the proposed software revolution, which may open up entirely new geochronological applications as well.

The research is funded for 3 years by the Natural Environment Research Council (NERC, Standard Grant #NE/T001518/1). Technical details about the project are provided here. Applications are to be submitted via the UCL recruitment website. Deadline: November 3, 2019; start date: as soon as possible after January 1, 2020.

Sir David Attenborough visits the lab



On Tuesday April 17, we had the great pleasure of giving a lab tour to Sir David Attenborough, who was the guest of honour at the Kathleen Lonsdale Building reopening ceremony. After a brief introduction to U-Pb, U-Th-He and K-Ar geochronology, our esteemed guest asked the pertinent question as to whether these chronometers could be cross-calibrated. Interestingly, improving such cross calibrations turns out to be one of our top priorities for the coming years!

Further information about Sir David's visit to the Department can be found here.

IsoplotR released to the world



IsoplotR is a free and open-source substitute for Kenneth Ludwig's popular Isoplot add-in to Microsoft Excel. The program is written in R and includes functions for U-Pb, Pb-Pb, 40Ar/39Ar, Rb-Sr, Sm-Nd, Lu-Hf, Re-Os, U-Th-He, fission track and U-series disequilibrium dating. IsoplotR can be run in three different modes: online, offline and from the command line. Its underlying principles are described in a paper that has been accepted for publication in:


Vermeesch, P., 2018, IsoplotR: a free and open toolbox for geochronology. Geoscience Frontiers, doi: 10.1016/j.gsf.2018.04.001.

Geologists discover 60 million-year-old meteorite impact

 

The LGC were part of a team of geologists who discovered the first recorded occurrence of vanadium-rich osbornite on Earth, from two sites on Skye, northwest Scotland, which are interpreted as part of a meteoritic ejecta layer. Vanadium-rich osbornite has only previously been reported in space dust from NASA missions, but on Skye it has been identified as an unmelted phase.


Drake, S.M., Beard, A.D., Jones, A.P., Brown, D.J., Fortes, D., Millar, I.A., Carter, A., Baca, J. B., Downes, H. (2017) Discovery of a meteoritic ejecta layer containing unmelted impactor fragments at the base of Paleocene lavas, Isle of Skye, Scotland. Geology, https://doi.org/10.1130/G39452.1


High throughput geochronology by automated phase mapping and LAICPMS

The first step in most geochronological studies is to extract dateable minerals from the host rock, which is time consuming, removes textural context, and increases the chance for sample cross-contamination. A collaborative research effort between the LGC and Rocktype Ltd. has developed a new method to rapidly perform in-situ analyses by coupling a fast Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectrometer (EDS) to a Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LAICPMS) instrument.

Vermeesch, P., Rittner, M., Petrou, E., Omma, J., Mattinson, C. and Garzanti, E., 2017, High throughput petrochronology and sedimentary provenance analysis by automated phase mapping and LAICPMS, Geochemistry, Geophysics, Geosystems (doi: 10.1002/2017GC007109)