Krystallisations og mineraliserings processer i “mushy layer”
Mange økonomisk vigtige ressourcer, så som platin gruppe elementer (PGE), vanadium og titan, findes i lagdelte intrusioner dannet ved størkning af smeltet bjergartsmasse. Lagdelte intrusioner er karakteriseret af lag med forskellige proportioner af mineraler. Lagene er oftest kontinuerte og kan følges op til mange hundrede kilometer langs bund sider og loft i intrusioner. Det er af stor betydning da de økonomisk interessant mineraler findes i sådanne lag.
Målet med undersøgelserne er at fremkalde et skift i forståelsen and lagdelingsprocesser og dermed efterforskningsmodeller for de ressourcer der findes i lagdelte intrusioner, herunder PGE, vanadium og titan. Forbedring af benyttede efterforskningsmodeller giver bedre muligheder for lokalisering og vurdering af malme, både under efterforskning og under udvinding af forekomsterne.
For at kunne gennemføre undersøgelserne skal nyt materiale indsamles. Deltagerne vil i samarbejde med kolleger fra Cambridge og Exeter universiteterne (UK) gennemføre en 5-6 ugers feltoperation i Skaergaards intrusionen på Grønlands vanskeligt tilgængelige østkyst. Skaergaards intrusionen er det måske bedste naturlige laboratorium for studier af lagdelingsprocesser.
Det nye materiale vil blive indsamlet for at belyse krystallisations og mineraliserings processer i ”mushy layer”, et lag af krystaller og bjergartssmelte i krystallisations zonen langs gulv, vægge og loft i den størknende bjergartsmasse. En fokusering på processer i denne krystallisationszone i felt- og laboratorie studier forventes at skabe et nybrud og grundlaget for fremtidige studier af lagdelte intrusioner af deres mineraliserings systemer.
Projektleder
Sam Weatherley
De Nationale Geologiske Undersøgelser for Danmark og Grønland
E-mail: [email protected]
Mushy Mineralizing Systems Seed Fund
Many of the world’s resources of economically important raw materials, such as the platinum group elements (PGE), vanadium (V) and titanium (Ti) are hosted in fossilized reservoirs of molten rock, otherwise known as layered intrusions. A special feature of these bodies is that different minerals and rock types are arranged into sets of layers that can persist uninterrupted for hundreds or even thousands of square kilometres over the floor, walls and roof of the intrusion. This is important because the layers can contain the high concentrations of metals such as vanadium and platinum that are needed to make mining possible.
This aim of this project is to precipitate a step-change in exploration models for commodities that are found in layered intrusions, with a special focus on PGEs, Ti and V. Improved exploration models will give better predictability over the location and concentration of ore in both the exploration and production stages.
To address this challenge, the project participants will make a 5-6 week long expedition with scientists from the University of Cambridge and University of Exeter to Skaergaard, an outstanding and well-studied natural laboratory on a remote section of East Greenland coast.
The new samples and observations collected in the field will feed into two pilot laboratory studies that will help constrain the mineralising processes that occur within the so-called ‘mushy layers’, which are the partially-solidified crystallisation zones on the floor, roof and walls of igneous intrusions.
It is intended that the new field observations and laboratory studies will constitute a major step towards the next generation of high-impact studies on layered intrusions and their mineralising systems.
