October 2023 - Cmi Capital Blog

Tracing Mantle-Oxygen Fugacity Changes Through the Great Oxidation Event: Insights from Apatite Inclusions in Brazilian Igneous Zircons

Moreira, H., Storey, C., Bruand, E. et al. Sub-arc mantle fugacity shifted by sediment recycling across the Great Oxidation Event. Nat. Geosci. 16, 922–927 (2023). https://doi.org/10.1038/s41561-023-01258-4 Substantial accumulation of free oxygen in the atmosphere occurred between ~2.45 and 2.20 billion years ago , with permanent atmospheric oxygenation commencing between 2.3 and 2.2 Ga. This »

A Pioneer’s Recollections – Part 2

Queensland’s Early DaysBY C. Duncan LaidleyBrisbane Courier (Qld. : 1864 – 1933), Saturday 27 October 1923, page 19 I find it most interesting to read the Brisbane Courier from 100 years ago on a Saturday morning. It brings into stark relief the modern world, that which remains much the same »

THE 975 Oz CURTIS NUGGET – FOUND AT GYMPIE

The Curtis Nugget, the largest in Queensland, was discovered in Gympie, Queensland in 1868 by Curtis and Brigg on a lease close to the initial claim of the discoverer of the Gympie Goldfield, James Nash. The claim where the Curtis nugget was found had been pegged earlier by George Curtis »

Formation Environments of Advanced Argillic Minerals & The Exploration Implications

This post is a summary of the excellent recent paper on the above topic in Economic Geology: Jeffrey W. Hedenquist, Antonio Arribas; Exploration Implications of Multiple Formation Environments of Advanced Argillic Minerals. Economic Geology 2022;; 117 (3): 609–643. https://doi.org/10.5382/econgeo.4880 Introduction Hydrothermal ore deposits are associated with alteration minerals, and one such alteration type »

A Pioneer’s Recollections – Part 1

I find it most interesting to read the Brisbane Courier from 100 years ago on a Saturday morning. It brings into stark relief the modern world, that which remains much the same and that which has evolved beyond belief in such a short period of time. Here is a transcription »

A new Lithospheric and Tectonic Model for Earth

Introduction The Earth’s lithosphere is its rigid outer shell, which rests on the more fluid asthenosphere. The thickness of the lithosphere varies, from a few kilometers at ocean spreading centers to 250-300 kilometers within continental cratons. There are two significant seismic boundaries in the crust and upper mantle: the Mohorovicic »

Geoscience – Rocks!

Month: October 2023