Ore deposits in an evolving Earth: an introduction

Abstract

Ore deposits form by a variety of natural processes that concentrate elements into a small volume that can be economically mined. Their type, character and abundance reflect the environment in which they formed and thus they preserve key evidence for the evolution of magmatic and tectonic processes, the state of the atmosphere and hydrosphere, and the evolution of life over geological time. This volume presents 13 papers on topical subjects in ore deposit research viewed in the context of Earth evolution. These diverse, yet interlinked, papers cover topics including: controls on the temporal and spatial distribution of ore deposits; the sources of fluid, gold and other components in orogenic gold deposits; the degree of oxygenation in the Neoproterozoic ocean; bacterial immobilization of gold in the semi-arid near-surface environment; and mineral resources for the future, including issues of resource estimation, sustainability of supply and the criticality of certain elements to society.

On the paragenetic modes of minerals: A mineral evolution perspective

“…However, we postulate that these uncommon elements were not sufficiently concentrated in Hadean hydrothermal fluids to generate that wide range of compounds. In spite of longstanding interest in the secular variation of sulfide-rich ore bodies (Laznicka 1973;Meyer 1988;Titley 1993;Barnes and Rose 1998;Goldfarb et al 2001;Groves et al 2005Groves et al , 2010Huston et al 2010;Leach et al 2010;Maier and Groves 2011;Jenkin et al 2015), the changing mineralogies of these deposits through time, especially regarding minerals containing relatively rare elements, have not been detailed to our knowledge. We therefore limit our list of the earliest hydrothermal chalcogenides to sulfides (and in a few cases arsenides) of the commonest transition metal elements, as well as PGE elements, which are thought to concentrate in fluids associated with ultramafic lithologies owing to their highly incompatible nature (Mungall and Naldrett 2008).…”

Method for Revealing Placer Gold Source

“…В районе среднего течения реки Адыча на сегодняшний день не было установлено россыпей с источниками в виде промежуточных коллекторов. Однако наличие россыпей с хорошо окатанным золотом при фактически полном отсутствии тяжелой фракции подразумевает возможность наличия промежуточных аккумуляций, продуктивных на россыпное золото [1,2,[4][5][6]8].…”