Manuel Keith

Manuel Keith
Friedrich-Alexander-University of Erlangen-Nürnberg | FAU · Department of Geography and Earth Sciences

Dr.

About

54
Publications
19,969
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
805
Citations
Additional affiliations
April 2019 - March 2022
Friedrich-Alexander-University of Erlangen-Nürnberg
Position
  • Professor (Assistant)
Description
  • Geochemistry, economic geology, magmatic petrology
August 2018 - March 2019
Technische Universität Berlin
Position
  • Research Fellow (faculty position)
Description
  • Geochemistry, economic geology
January 2016 - July 2018
University of Leicester
Position
  • Research Associate
Description
  • Economic geology, geochemistry

Publications

Publications (54)
Article
Tellurium (Te) is an important element for green technologies, including thin film photovoltaic panels. Stagnating supply caused by its by-product dependency together with an increasing demand will likely lead to a shortage in the near future. Pyrite may represent a potential target for the direct recovery of Te, since the concentrations of Te can...
Article
Boiling is a crucial process triggering ore formation in magmatic-hydrothermal systems and controlling the enrichment of precious and rare metal(loid)s in epithermal-porphyry mineralizations. Steep physicochemical gradients during boiling of hydrothermal fluids at shallow water depths caused metal(loid) precipitation along a 3 km long Pb-Zn-Ag vein...
Article
Full-text available
Submarine caldera volcanoes may host several hydrothermal systems along the caldera wall and related to volcanic cones. Fluid boiling and magmatic volatile influx are common processes in shallow (<2000 mbsl) subduction zone-related environments causing variations in the mineralogical and chemical composition of seafloor hydrothermal mineralizations...
Article
Porphyry deposits host various trace elements in economic amounts, but the hydrothermal processes causing their fractionation and enrichment are still not fully understood, but vital to target the most prospective mineralisation. We present the first micro-analytical study on the trace element composition of pyrite from the Koloula Cu-Au porphyry i...
Conference Paper
Full-text available
Recent studies have shown high-grade Au-ores result from Au remobilization from preexisting mineralization, assisted by fluid-induced, coupled dissolution-reprecipitation (CDR) replacement reaction and scavenging by sulfosalt melts rich in low-melting point chalcophile elements (LMCE). However, these processes are poorly understood in modern, arc-r...
Conference Paper
Full-text available
Zegkinoglou N, Kilias S.P., Zygouri E, Nomikou P, Keith M, Vaněk A, Mihaljevič Vaňková M, Smith D.J., Polymenakou P (2022) Deciphering thallium deportment and remobilization in shallow-water massive sulfides at the Kolumbo arc-volcano, Greece: evidence from in situ LA-ICPMS study and thallium-isotope fractionation. In: Christie AB (ed.) Proceedings...
Article
Full-text available
Back-arc spreading centres and related volcanic structures are known for their intense hydrothermal activity. The axial volcanic edifice of Maka at the North Eastern Lau Spreading Centre is such an example, where fluids of distinct composition are emitted at the Maka hydrothermal field (HF) and at Maka South in 1,525-1,543 m water depth. At Maka HF...
Conference Paper
Full-text available
A more sustainable society with CO 2 neutral energy production requires substantial amounts of trace metal(loids). However, our understanding about the fractionation processes of these elements between the epithermal and porphyry environment is still limited, but may be essential to secure the future supply of these rare commodities. The porphyry-e...
Conference Paper
Full-text available
Target settings to secure sustainable access to raw materials include seafloor massive sulphide (SMS) resources. Gold-rich SMS deposits, are often the result of complex interplay of multiple Au enrichment events. Recent studies have shown that high-grade Au ores result from Au remobilization from preexisting mineralization, driven by fluid-induced...
Article
Full-text available
The Pefka Cu-Au-Te-In-Se and nearby St Philippos Pb-Zn-Bi-Sn-Ge-Ga-In vein- and breccia-type deposits in western Thrace, Greece, display strong similarities, but also differences in terms of mineralization style, ore mineralogy, and chemistry, and host rock compositions. The Pefka mineralization consists of two crosscutting vein systems with high s...
Conference Paper
Full-text available
Submarine "black smoker" systems and their associated seafloor massive sulfides (SMS) may represent economic resources for future generations. However, the processes leading to spatial variations in the mineralogical and chemical composition of subduction zone-related hydrothermal systems remain poorly constrained. The large submarine caldera of Ni...
Article
Shallow (<1500 mbsl) submarine arc-related hydrothermal systems can host base (Cu), precious (Au) and volatile elements (As, Se, Sb, Te, Tl) in significant quantities. Their wide application in the high-tech industry, but a potential eco-toxicological footprint gives them a strategic importance. However, the processes that concentrate these element...
Article
Hydrothermal activity is abundant at volcanic structures in subduction zones, including those associated with young volcanism in back-arc regions. Fluid boiling is a common process in these environments, but its frac-tionation and precipitation effects on trace metals and metalloids are still poorly constrained. The submarine back-arc hydrothermal...
Article
Full-text available
Fluid conditions of shallow marine hydrothermal vent sites (<200 mbsl) in island arcs resemble those of subaerial epithermal systems. This leads to a distinct mineralization-style compared to deeper arc/back-arc (>200 mbsl) and mid-ocean ridge-related environments (>2000 mbsl). At Calypso Vents in the Bay of Plenty and Paleochori Bay at the coast o...
Article
Full-text available
Active, shallow-water (2–10 m below sea level) and low temperature (up to 115 C) hydrothermal venting at Paleochori Bay, nearshore Milos Island, Greece, discharges CO2 and H2S rich vapors (e.g., low-Cl fluid) and high-salinity liquids, which leads to a diverse assemblage of sulfide and alteration phases in an area of approximately 1 km2. Volcanicla...
Conference Paper
Full-text available
Tellurium demand is projected to surpass the current supply due to its importance in the green energy sector (e.g. thin film photovoltaic). An additional source to the present production from anode slimes could be the direct recovery from pyrite, which may secure the future supply of Te for the high-tech industry. Although it is known that the alka...
Conference Paper
Full-text available
Submarine "black smoker" systems and their associated seafloor massive sulphides (SMS) may represent economic resources for future generations. However, the geochemical characteristics in subduction zone-related systems and their spatial variations remain poorly constrained from a micro-analytical perspective. The large caldera of Niuatahi volcano...
Conference Paper
Full-text available
Identification of terrestrial hydrothermal processes, as signals of volcanic unrest or causes of explosive volcanic behaviour, is crucial in volcanic hazard assessment. However, the role of hydrothermal processes in triggering volcanic hazards in the marine environment remain poorly understood, hindering effective assessment. Hydrothermal vents in...
Article
Tellurium has a wide variety of applications, most importantly in the solar energy industry and is eco-toxicologically significant; however, the magmatic-hydrothermal processes causing the pronounced Te enrichment together with Au in some epithermal districts are still poorly constrained. Hydrothermal and alkaline magmatic activity in post-subducti...
Article
Full-text available
Magnetite is a common accessory phase in various types of ore deposits. Its trace element content has proven to have critical implications regarding petrogenesis and as guides in the exploration for ore deposits in general. In this study we use LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry) analyses of trace elements to che...
Article
Full-text available
The Troodos ophiolite, Cyprus is the principal on- land analogue for mafic-hosted volcanogenic massive sulfide (VMS) deposits. This study, for the first time, presents sulfur isotope (δ³⁴S) data on a regional scale from VMS deposits and other mineralised zones across the Troodos ophiolite. In combination δ³⁴S, Se/S ratios and trace element chemistr...
Conference Paper
Full-text available
Hydrothermal systems with black smoker mineralization represent modern analogues to ancient volcanogenic massive sulfides (VMS). Although, the formation processes have been studied extensively at mid-ocean ridges, especially the element transport at hydrothermal fields in active island arc settings is still poorly constrained. Magmatic degassing fr...
Conference Paper
Full-text available
Understanding the pathways and processes of the sequestration of Tl in modern SMS is key to VMS genetic and geometallurgical factors1. LA-ICP-MS trace element analyses of primary colloform pyrite (Py1) and recrystallized fine­grained pyrite (Py2) and euhedral zonal pyrite (Py3), and sphalerite (Sph) (inner sulfide­barite core), and, orpiment­type A...
Article
Full-text available
Ore deposits are loci on Earth where energy and mass flux are greatly enhanced and focussed, acting as magnifying lenses into metal transport, fractionation and concentration mechanisms through the lithosphere. Here we show that the metallogenic architecture of the lithosphere is illuminated by the geochemical signatures of metasomatised mantle roc...
Conference Paper
Full-text available
Thallium (Tl) is considered as toxic for human and animal organisms, microorganisms and plants (Peter and Viraraghavan 2005; Karbowska 2016). Thallium is redox active and has two oxidation states (Tl 1+ and Tl 3+), while Tl 1+ is believed to be the most common in Tl minerals (Xiong, 2007; George et al., 2019);and, monovalent Tl (Tl 1+), that is bel...
Article
The volcanogenic massive sulfide (VMS) deposits in the Troodos ophiolite (Cyprus) are ancient analogues for modern day seafloor massive sulfide mineralisation formed in a supra-subduction zone environment. In this study we present the first detailed in situ study of trace elements in sulfides from twenty VMS deposits hosted in the Troodos ophiolite...
Article
Full-text available
Most magmatic-hydrothermal Cu deposits are genetically linked to arc magmas. However, most continental or oceanic arc magmas are barren, and hence new methods have to be developed to distinguish between barren and mineralised arc systems. Source composition, melting conditions, the timing of S saturation and an initial chalcophile element-enrichmen...
Article
Full-text available
Table 1. Compilation of the key magmatic and hydrothermal data for the studied ore deposits.
Article
Full-text available
Epithermal gold mineralisation is found in a wide compositional range of host lithologies, but despite the diversity the alteration mineral assemblages are often similar between deposits. Notable exceptions are those gold deposits hosted in alkaline host rocks. Alkaline-hosted epithermal deposits are rare, but important, as they include some of the...
Article
The Troodos ophiolite represents one of the best-preserved fossil analogs of modern oceanic crust and includes numerous volcanic-hosted massive sulfide deposits. The Skouriotissa deposit can be separated into a stockwork ore zone and an overlying massive sulfide lens that is covered by metalliferous sediments representing the former sulfide–seawate...
Conference Paper
Full-text available
The Manus basin is a young and rapidly opening back-arc basin and has been considered a typical setting, in which VMS deposits may have formed. Water and rock samples were collected from different hydrothermal areas in the eastern Manus Basin to assess the effects of variable magmatic fluid inputs and crustal composition on vent fluid geochemistry...
Article
Submarine hydrothermal sulfide ores occur at mid-ocean ridges, intra-oceanic arcs and in back-arc basins associated with host rocks of highly variable composition. Pyrite is the dominant sulfide mineral in most samples presented within this study, and thus the trace element composition of pyrite may reflect the different metal sources and precipita...
Thesis
The chemical exchange and heat transfer between the oceanic lithosphere and the surrounding oceans is dominantly controlled by hydrothermal activity. During the last decades numerous active and inactive submarine hydrothermal vent fields have been discovered along convergent and divergent plate margins including mid-ocean ridges, back-arc basins an...
Article
Full-text available
Experimental studies have shown that temperature, pressure, sulfur fugacity (fS2), and oxygen fugacity ( fO2) influence the Fe content of sphalerite. We present compositional in situ data on sphalerite from submarine volcanic-hosted massive sulfide (VHMS) ores of hydrothermal vents from different plate tectonic settings and with variable host-rock...
Article
Full-text available
The geochemistry and petrology of tonalitic to trondhjemitic samples ( n = 85) from eight different plagiogranite intrusions at the gabbro/sheeted dyke transition of the Troodos Ophiolite were studied in order to determine their petrogenetic relationship to the mafic plutonic section and the lava pile. The plagiogranitic rocks have higher SiO2 cont...

Network

Cited By

Projects

Projects (8)
Archived project
NERC-funded consortium project researching the geological cycling and recovery of tellurium and selenium
Project
1) Define the δ82/76Se composition of submarine back-arc hydrothermal precipitates 2) Study the δ82/76Se fractionation processes during back-arc seafloor mineralization 3) Fingerprint sub-seafloor hydrothermal processes by a multiple stable isotope (δ82/76Se, δ34S, Δ33S) approach 4) Determine the δ82/76Se, δ34S and Δ33S isotope signature of back-arc lavas that are related to submarine hydrothermal mineralizations 5) Quantify the Se and S flux in submarine back-arc hydrothermal systems
Project
1. The chemical and mineralogical composition of magmatic sulphide globules vary between convergent and divergent plate margins. The magmatic processes that account for these differences are poorly constrained, but can be identified by comparing the chalcophile trace element composition of sulphide segregates and their host lithologies from MOR, back-arc and island arc systems. 2. Magmatic sulphide globules from MOR segments with variable spreading rate and hotspot influence are distinct in their chemical and mineralogical composition. The processes causing these differences are unknown to date, but it is likely that they are controlled by the melt source in the mantle and by processes acting during magma ascent. 3. The trace element composition of magmatic sulphide globules varies with depth in the oceanic lithosphere. The processes that cause these variations are widely unknown; samples from different sections of the crust and the upper mantle allow to investigate these processes for the first time with lithosphere depth. 4. Magmatic sulphide globules hosted in samples of different age are chemically and mineralogical distinct. This has not been investigated to date; samples recovered at variable distance from a MOR spreading centre with and without hotspot influence and from different sections of the lava pile reflect an age progression and allow to study the composition of magmatic sulphide segregates with respect to the temporal evolution of the magmatic system.