Jan Falkenberg

Jan. J. Falkenberg

PhD Student
Lehrstuhl für Endogene Geodynamik (Prof. Dr. Haase)
+499131 85-69604
jan.falkenberg@fau.de
Schloßgarten 5
91054 Erlangen

Project title: Magmatic and hydrothermal prerequisites for porphyry-epithermal mineralization in continental volcanic arcs, Thrace, NE Greece

The Priority Program “Dynamics of Ore Metals Enrichment – DOME (SPP 2238) focuses on answering open questions in the dynamics of ore metals enrichment in nature. To achieve economic valuable and sustainable resources most metals need to be enriched by a factor of about 1000 from the typical concentrations in Earth´s crust and mantle. Establishing conclusive and predictive models is of utterly importance to secure the raw materials for the present and future generations.

Our project part focuses on constraining the magmatic and hydrothermal prerequisites which are needed to form economic valuable ore deposits. We will sample different plutonic and sub-volcanic/volcanic rocks in the Maronia-Leptokarya magmatic corridor(Thrace, NE Greece) which host porphyry-epithermal style mineralisations and represents a natural laboratory to investigate ore-forming processes in deposits emplaced at various crustal depth and lateral extent from the paleo-subduction zone. Constraining the magmatic ingredients for the metal anomalies in this post-subduction and post-accretion environment is one major goal. On the deposits scale we will focus on the chemistry of hydrothermal sulphides in different vein-types of porphyry-epithermal style mineralization associated with various alteration assemblages and establish the hydrothermal processes forming the exotic mineralogy and element enrichments of critical and energy critical elements (e.g. Ga, Ge, Se, Sb, Te, Re and Bi). Combining the magmatic and hydrothermal processes we will create predictive models which ultimately will explain why and how an island arc system becomes mineralized or stays barren.

 

Methods I use:

In-situ mineral chemistry:

• Major elements: electron microprobe (EPMA)
• Trace elements: laser ablation inductively coupled mass spectrometry (LA-ICP-MS)

Whole-rock chemistry:

• Major elements: X-ray fluorescence spectroscopy (XRF)
• Trace elements: Inductively coupled plasma mass spectrometry (ICP-MS) and Hydride generation atomic fluorescence spectrometry (HG-AFS)

 

Project title: Submarine hydrothermal systems in subduction-related settings: Constraints on hydrothermal fluid evolution, metal fractionation and ore genesis.

Submarine hydrothermal systems occur along divergent and convergent plate margins all over the world. Seawater penetrates the ocean floor through pathways like faults, heats up and evolves due to fluid-rock interaction in a hydrothermal circulation cell to an acidic, hot and reducing “fluid-cocktail” enriched in metals and metalloids. On contact with cold oxygenated seawater, sulphide minerals precipitate due to rapid changes in physicochemical fluid parameters (e.g. temperature, pH, oxygen- and sulphur fugacity) forming “black smoker chimneys”. These submarine “hot springs” have been inferred to be the possible source for early life on earth. Furthermore, they are believed to be modern analogues to volcanic-hosted massive sulphide (VHMS) deposits currently mined on land. Seafloor massive sulphides can be an essential future resource for metallic raw materials needed e.g. for the “green transition” and could support traditional land-based mining.

Our research focuses on sulphide mineralogy and geochemistry of pyrite, sphalerite and chalcopyrite in submarine hydrothermal vent fields in intra-oceanic arc settings (e.g. the Tonga-Kermadec island arc and Lau back-arc basin) which are typically enriched in economic important elements e.g. copper, gold, arsenic and antimony compared to their mid-ocean ridge counterparts. Using major- and trace elements as well as radiogenic (lead) and stable (sulphur) isotope signatures, we will decipher the metal and metalloid sources as well as the element enrichment- and fractionation processes leading to these metal anomalies on the ocean floor. Understanding these processes is fundamental to develop new exploration tools for seafloor massive sulphides and deposits on land.

 

Methods I use:

In-situ mineral chemistry:

• Major elements: electron microprobe (EPMA)
• Trace elements: laser ablation inductively coupled mass spectrometry (LA-ICP-MS)

Radiogenic isotopes:

• Pb isotopes: Multicollector inductively coupled mass spectrometry (MC-ICP-MS)

Publications