Description:
The formation of economic ore deposits typically requires a 1000-fold enrichment of metals into concentrated ore bodies. The DFG-funded Priority Program "Dynamics of Ore Metals Enrichment" (DOME) aims to understand the fundamental processes involved so as to develop more efficient and sustainable ways to ensure metals supply in the future. Substitution and recycling play increasing roles in the “resource mix” but the near future will see growing demand for primary resources of many metals, particularly to support technologies needed for the energy transition. The projects combine case studies of ore formation in the field, laboratory experiments to constrain the physical and chemical properties relevant for metal transport and precipitation, and thermal-mechanical modelling to translate these results into testable geologic models (see https://www.uni-potsdam.de/en/spp2238/).
DOME is coordinated at the University of Potsdam by Prof. Max Wilke together with a committee of scientists from German universities (University of Freiburg and University of Münster) and the GFZ section 3.1 (Sarah Gleeson, Robert Trumbull, Philipp Weis), which is also involved in nine individual funded projects:
Description:
This research project will study the origin and evolution of the ore-forming fluids and formation mechanisms at the world-class Neves Corvo deposit in Portugal by the combination of fluid and melt inclusions, and numerical simulations. Neves Corvo deposit is one of the leading producers of Cu and Zn concentrates in the European Union. It stands out within the Iberian Pyrite Belt (IBP) in terms of size, Cu-Zn grades and tonnages, and also because of notable Sn mineralization. The association of the deposit with black shales and metavolcanics rocks, as well as its complex and spatially zoned metals associations, has led to confusion about how the mineralization formed. The aim of this integrated research is to determine the first-order chemical and physical processes that control metals enrichment, and the favorable geodynamic constraints on heat and fluid flow that allow such giant deposits to form.
Project details:
Duration: 2021 - 2025
Funding: DFG
PIs: Prof. Sarah Gleeson, Dr. Robert Trumbull, Dr. Philipp Weis
Description:
Critical for understanding the formation of granite-related hydrothermal Sn-W deposits as well as deposits of critical metals like Li and Ta-Nb in pegmatites is the magmatic-hydrothermal transition, which is hard to define from the rock record. Theory predicts that boron isotopes will fractionate significantly between magma and fluid at the transition, and this isotopic shift may be recorded in the minerals like tourmaline and white mica, which are widespread and common in these kinds of deposits. If validated, this would provide a major contribution to understanding magmatic-hydrothermal ore formation but key information is missing: the B-isotope fractionation between granitic melts and the fluids derived from them. That is the goal of this project.
Project details:
Duration of project: 2020 - 2022
Funding: DFG
PIs: Dr. Robert Trumbull, Dr. Bernd Wunder (3.6), Prof. Max Wilke (University of Potsdam), Prof. Sandro Jahn (University of Cologne)
Description:
Future exploration for mineral resources will target greater depths and submarine settings, which is costly and technically challenging. For this development, we need robust predictive models that can capture the first-order processes within entire ore-forming systems. Magmatic-hydrothermal ore deposits form our largest resources of Cu, Mo, Sn and W and are formed by fluids released from magmatic intrusions into a hydrothermal system within the country rock. The potential to form world-class deposits critically depends on cross-boundary fluid fluxes at this magmatic-hydrothermal interface, which is the key unknown in our current understanding of these deposits and can so far only be parameterized in numerical simulations. Capturing these interface processes requires a fundamentally new modelling approach with a continuum that extends beyond the roots of hydrothermal systems and bridges the gaps between fluid flow and magma dynamics. Furthermore, and very important for geological realism, the model simulates dynamic permeability changes and focused flow caused by fractures.
Project details:
Duration of project: 2021 - 2025
Funding: DFG
PI: Dr. Philipp Weis
Description:
Ore metal enrichment in basin-scale hydrothermal systems results from a perfect convergence of chemical and physical processes on different temporal and spatial scales. These systems can only be quantitatively understood by observations and studies beyond the deposit scale. Numerical process models have the potential to identify first-order controls on ore formation and provide physical and chemical constraints on the feasibility and efficiency of hydrothermal systems to generate world-class deposits, which may help guiding future exploration. In this collaborative project, we will develop and apply a reactive transport model for ore formation in sedimentary basins, using the geochemical model GEMS3 and the fluid flow model CSMP++. With this coupled model for reactive transport, we will quantitatively investigate the respective roles of key parameters like fluid salinity, oxidation state, pH, metal and sulfur availability, basin-scale heat flux, topography, basin strata, pore space and permeable fluid pathways on the dynamics of ore metals enrichment.
Project details:
Duration of project: 2024 - 2027
Funding: DFG
PI: Dr. Philipp Weis, Thomas Wagner (RWTH Aachen)
Peralkaline magmatic rocks host some the largest accumulations of Zr, Nb, and rare earth elements (REE) on Earth. Of particular importance at present or in the near future are or will be deposits in silica-undersaturated alkaline rocks (Khibiny and Lovozero massifs, Kola Peninsula, Russia, and Ilimaussaq complex, southern Greenland), which are characterized by a complex mineralogy. So far, these rocks are little studied experimentally, and thus fundamental data on solubility and complexation of these elements and even on phase relationships are missing. In this project, we address some of the open questions and determine the solubility of the ore minerals wöhlerite, eudialyte, lueshite, and loparite (including the concentrations of Nb, Zr, Ti and REE) in SiO2-undersaturated alkali aluminosilicate melts as functions of peralkalinity and of the concentrations of F and H2O. These experiments also provide information on phase relationships and the complexation of Nb and Zr in peralkaline silicate melts.
Project details:
Duration: 2021-2025
Funding DFG
PIs: Christian Schmidt, Ilya Veksler
In this study, we investigate the capacity of fenitising fluids for remobilization, transport, and further concentration of rare earth elements (REE), Nb and Zr, and thus their role in the formation of economic rare metal ore deposits in carbonatites. Carbonatites are the world’s most important source for the critical raw materials REE and niobium. Fenitising fluids are alkali-rich hydrous very mobile and reactive fluids typically expelled from carbonatites, and that are responsible for extensive high-temperature metasomatic alteration of country rocks, i.e. for the formation of fenites.
This study is aimed at testing the working hypothesis that bastnäsite ((Ce,La,Nd,Y)(F,OH)CO3)), pyrochlore ((Na,Ca)2Nb2O6(OH,F,O)) and, perhaps, baddeleyite (ZrO2) deposits in carbonatites result from autometasomatic remobilisation of REE, Nb and Zr by highly concentrated alkali carbonate fluids with compositions intermediate between brines and hydrated salt melts. The idea is that the rare metals can be remobilised by reactions of fluid with magmatic, earlier crystallised apatite, REE- and Nb-bearing perovskite solid solutions, and eudialyte. Significant amounts of REE may be also released by recrystallisation of primary magmatic calcite. Specific objectives of the proposed research include:
(1) Experimental study of phase equilibria in the system Na2O–CO2–H2O (±REE2O3, Nb2O5, SiO2, CaO) at intermediate water contents by visual observations and in situ Raman spectroscopy using a hydrothermal diamond-anvil cell. Particular attention will be paid to fluid immiscibility.
(2) Complexation of Nb and Zr in peralkaline silicate glasses studied using Raman and X-ray absorption spectroscopy.
(3) Experimental study of the solubility of REE-bearing apatite, pyrochlore, loparite, and baddeleyite in carbonate-(chloride-sulphate) brines at 0.1–0.2 GPa and 500–800 °C. Particular attention will be paid to the solubility of pyrochlore because of the inconsistency of literature data.
(4) Comparison of experimental results in synthetic systems with analyses of natural
fluid inclusions in minerals formed early or relatively early in carbonatites (pyrochlore, apatite, and others) and in minerals from fenites (particularly quartz, also fluorite, and others).
Project details:
Duration: 2024-2027
Funding DFG
PIs: Christian Schmidt, Ilya Veksler, Ingo Horn