Reiner Klemd's research while affiliated with Friedrich-Alexander-University of Erlangen-Nürnberg and other places

Publications (288)

Article
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Porphyry-epithermal systems associated with high-K calc-alkaline to alkaline igneous host rocks may be prospective for the recovery of Te among related elements like Cu, Ag, and Au. Limnos Island, as part of the Tethyan magmatic belt, is such an example, where (telescoped) porphyry-epithermal mineralization is accompanied by different alteration-st...
Poster
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Pyrite-marcasite and Ag-enriched galena veins and disseminations are present in the Loutros epithermal system. Fluid inclusion data suggest that the ore-forming fluids had a meteoric/seawater origin, with minor magmatic contribution at the first pyrite-marcasite stage and increased meteoric and/or seawater contribution at the second galena stage.
Article
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The Permian basalts in the Central Asian Orogenic Belt (CAOB) are crucial for constraining the closure of the Paleo-Asian Ocean. However, the origin of these basalts is still under discussion. Here, we present comprehensive bulk-rock geochemical, Sr−Nd−Pb−Hf isotopic, and zircon U−Pb−Lu−Hf isotopic data of the Liuyuan basalts and coexisting gabbros...
Article
High-temperature and high-pressure (high-grade) metamorphic complexes of variable ages are common in the Central Asian orogenic belt (CAOB), and their precise geochronology and origin are essential to unravel the orogenic architecture and crust-production rate of the CAOB. Hereby it is essential to differentiate between pre-orogenic Precambrian bas...
Article
Compositional changes of successively emplaced magmatites can be used to infer changes in their petrogenetic evolution and geodynamic setting. The central-northern Lhasa terrane hosts extensive Late Cretaceous magmatism, however, the mechanism that triggered the magmatism and its relationship to the directly preceding Late Cretaceous tectonic trans...
Article
The genesis of banded iron formations is commonly associated with anoxic and iron-rich (ferruginous) marine conditions throughout the Archean to Paleoproterozoic, and occasionally in the Neoproterozoic. In recent studies, ~2 million-year-old banded iron-rich sedimentary rocks with alternating Fe- and Si-rich bands occurring in the Cape Vani sedimen...
Article
Although it has been suggested that the trace element patterns of sedimentary pyrite can be affected by early diagenesis, detailed studies on modern marine environments addressing this hypothesis are scarce. Organoclastic sulfate reduction (OSR) and sulfate-driven anaerobic oxidation of methane (SD-AOM) are the dominant sulfate reduction processes...
Conference Paper
Eclogite-hosted metamorphic veins mark former fluid migration pathways during a subduction- exhumation cycle, and allow to trace fluid-mediated element transfer across lithologies, to ultimately metasomatize the mantle wedge. Fluids can be generated by dehydration reactions at different P-T conditions in various lithologies, all influencing how dif...
Article
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The Fe isotope systematics of subducted lithologies are crucial for the understanding of redox-dependent mass transfer in subducting slabs, with consequences for the compositions of arc magmas and of the deep mantle. We investigated eclogites, metagabbros, and paragneisses from the Variscan Münchberg Massif to unravel whether their Fe isotope compo...
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...
Article
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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
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Accretionary complexes are a major component of the Central Asian Orogenic Belt (CAOB) and are important for understanding its architecture and evolution. The Wuwamen accretionary complex in the Chinese South Tianshan contains a tectonic mélange that witnessed the dynamic evolution from early accretion to final collision of the western CAOB with th...
Article
The Central Zone of the Limpopo Belt in southern Africa is a complex polymetamorphic terrane that has experienced three metamorphic events, at 3.22 Ga (M 1), 2.71-2.56 Ga (M 2) and 2.02 Ga (M 3). On the basis of a previous detailed petrological and geothermobarometrical study of a newly discovered supracrustal enclave within the Bulai Pluton (ca. 2...
Article
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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
In the absence of strong fluid-rock interactions, stable isotopes of oxygen (δ18OV-SMOW) and iron (δ56FeIRMM-524a) are thought to behave conservatively during subduction zone metamorphism. High-pressure minerals may attain isotopic equilibrium, and preserve it in case of limited diffusion. High-Fe3+/ΣFe minerals tend to enrich heavy Fe isotopes com...
Article
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High-silica (<70 wt% SiO2) magmas are usually believed to form via shallow crustal–level fractional crystallization of intermediate magmas. However, the broad applicability of this model is controversial, because the required crystal-melt separation processes have rarely been documented globally up to now. The ca. 50 Ma Nyemo composite pluton of th...
Article
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The Variscan Central-Sudetic Ophiolites (CSO) are located in the Sudetes, the NE segment of the Bohemian Massif. The Devonian CSO display highly depleted, harzburgite mantle sections containing gabbroic dykes and local occurrences of mostly isotropic, large gabbroic bodies as well as volcanic rocks. The ultramafic rocks locally show melt percolatio...
Conference Paper
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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...
Article
Collision-induced subduction transference may have triggered subduction of the Neo-Tethys oceanic lithosphere. To verify this proposition, we present an integrated geochemical and geochronological studies of new and published data of the Permian-Triassic magmatism in the Lhasa Terrane. The newly identified Chongni mafic intrusions (gabbros and dior...
Conference Paper
Stable Fe isotope fractionation (δ56Fe = [(56Fe/54Fe)sample/(56Fe/54Fe)IRMM-524a standard − 1] × 1000) is sensitive to redox processes. Under equilibrium conditions, the heavy Fe isotopes tend to partition into more oxidized phases as Fe3+, but the bonding environment can also play a substantial role. We investigate Fe isotope fractionation between...
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...
Conference Paper
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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
The Palaeocene-Eocene (66–41 Ma) hosts the most intense stage of extensive magmatism in the Gangdese belt of southern Tibet. However, the magma sources and tectonic setting of this magmatic belt have been a matter of discussion for decades. In this study, we conducted zircon geochronological and geochemical studies on Eocene gabbroic rocks and gran...
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
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
Full-text available
Eclogites, metagabbros, and paragneisses from the Variscan Münchberg Massif record a complex succession of igneous, hydrothermal and metamorphic processes. The geodynamic setting related to the protolith formation and the impact of different types of fluid-rock interactions have been uncertain up to now. We use major and trace element chemistry as...
Article
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Compiled data show the age progression of magmatic centers along two approximately linear profiles from NE Greece and NW Turkey to the South Aegean Volcanic Arc (SAVA). The age progression reveals the southwestward migration of arc magmatic activity from Oligocene to present, perpendicular to the Hellenic Trench. This is in accordance with the migr...
Article
Index minerals in metamorphic rocks, such as coesite, glaucophane, or lawsonite, are of great importance to understand high-pressure (HP) to ultrahigh-pressure (UHP) metamorphism, the thermal gradient, and the geodynamics of subduction zones. Deerite is thought to be diagnostic for blueschist-facies metamorphism in cold subduction environments and...
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
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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
The Epupa Complex of northern Namibia constitutes the southwest -ern margin of the Archean Congo Craton of central Africa. We present new petrolog-ical and geochronological data for metasedimentary migmatites that decode the poorly-known Paleoproterozoic to Mesoproterozoic evolution of this remote part of the craton. Detrital magmatic zircons with...
Article
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Subduction zones are often characterized by the presence of strong trench-parallel seismic anisotropy and large delay times. Hydrous minerals, owing to their large elastic anisotropy and strong lattice preferred orientations (LPOs), are often invoked to explain these observations. However, the elasticity and the LPO of chloritoid, which is one of s...
Article
Sulphur is of particular importance in the subduction zone system, as it is thought to be intimately related to the arc redox state and metallogenesis above the slab. Knowing the sulphur isotope compositions of the subducted slab, and identifying the δ34S variations between the pre-subduction oceanic lithosphere and its high-pressure (HP) equivalen...
Article
The Oligocene shoshonitic Maronia pluton in NE Greece is part of an age-progressive belt of calc-alkaline intrusions and associated with a porphyry Cu-Mo±Re±Au mineralisation. We present new data on mineral and whole rock compositions as well as Sr, Nd and Pb isotopes of the monzodioritic to granitic rocks from Maronia, including the mineralised mi...
Article
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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
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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...
Article
Olivine is one of the most important minerals used to reconstruct magmatic processes, yet the rare earth element (REE) systematics of Fe-rich olivine in igneous rocks and ore deposits is poorly understood. As detected by in situ laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis, cumulate fayalite (Fe2SiO4) in the Pale...
Article
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Extensive angular unconformities that occur across the Tianshan Orogen provide insight into the Paleozoic tectonic evolution of the southwestern Central Asian Orogenic Belt. This study presents new geochronological and geochemical data to unravel the age and origin of a pronounced angular unconformity in the Baluntai domain of the Chinese Western T...
Conference Paper
The Münchberg Massif (German Bohemian Massif) is an allochthonous nappe pile within the Saxothuringian zone of the Variscan orogen. Its uppermost nappe (Hangendserie) contains eclogites and paragneisses which were both affected by early Variscan high-pressure metamorphism. A dark, kyanite-free eclogite (Mg# ~45–70, Al2O3 ~13–16 wt.%) can be disting...
Article
Precambrian microcontinents are an essential component in the tectonic evolution and architecture of the Central Asian Orogenic Belt (CAOB). However, the early crustal evolution and origin of Precambrian micro-continents remain poorly constrained due to the scarcity of early Precambrian rocks. The Chinese Central Tianshan Block (CTB) constitutes a...
Article
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The Platreef, at the base of the northern limb of the Bushveld Complex in South Africa, hosts platinum-group element (PGE) mineralization in association with base-metal sulphides (BMS) and platinum-group minerals (PGM). However, whilst a magmatic origin of the stratiform mineralization of the upper Platreef has been widely confirmed, the processes...
Article
It has been shown that certain host minerals can robustly shield mineral inclusions and prevent loss of petrochronological information during subsequent thermal events. Rutile inclusions in garnet may crystallize under a wide range of metamorphic conditions and thus it is expected to be a useful geochronometer for constraining different stages of a...
Article
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The Maronia Cu-Mo ± Re ± Au deposit is spatially related to a microgranite porphyry that intruded an Oligocene monzonite along the Mesozoic Circum-Rhodope belt in Thrace, NE Greece. The magmatic rocks and associated metallic mineralization show plastic and cataclastic features at the southeastern margin of the deposit that implies emplacement at th...
Article
Situated in the centre of the Paleoproterozoic Bushveld Large Igneous Province (LIP) of South Africa the Vergenoeg F-Fe-REE deposit is one of the largest, but at the same time most unusual, fluorite deposits on Earth. In situ major and trace element analyses of fayalite, magnetite, ilmenite, fluorapatite, fluorite and allanite from fayalite-rich ro...
Article
Deeply buried Upper Permian (Zechstein) carbonates in the southwestern North German Basin host widespread Zn-Fe-Pb sulfide mineralization. The spatial extent of the sediment-hosted mineralization, the geochemical formation conditions, and the number of mineralizing events that are manifested in the Permian sedimentary rocks are an ongoing matter of...
Article
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Sulfur belongs among H2O, CO2, and Cl as one of the key volatiles in Earth’s chemical cycles. High oxygen fugacity, sulfur concentration, and δ34S values in volcanic arc rocks have been attributed to significant sulfate addition by slab fluids. However, sulfur speciation, flux, and isotope composition in slab-dehydrated fluids remain unclear. Here,...
Article
The Central and Western Zones of the Halls Creek Orogen (HCO) of the East Kimberley region of Western Australia host various Paleoproterozoic layered mafic–ultramafic intrusions. The 1856 ± 2 Ma layered mafic–ultramafic Panton Intrusion of the Central Zone contains a reef-type platinum-group element (PGE) mineralisation associated with metamorphose...
Article
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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...
Conference Paper
Fe isotopes provide a promising tool to trace fluid-rock interactions and mass transfer in subducting lithosphere due to redox-sensitive isotope fractionation (phases rich in Fe3+ preferentially incorporate the heavier isotopes). Our study aims at understanding to which extent the Fe isotopes in the subducted crust reflect (1) igneous protolith for...
Article
Abundant Neogene adakitic magmatism occurred in the southern Lhasa subterrane after the onset of the India−Asia collision while convergence continued. However, the tectonic setting and magmatic evolution of the adakitic rocks are still under discussion. This study includes new mineral chemical and whole-rock geochemical data as well as zircon U-Pb...
Conference Paper
The Epupa Complex (EC) represents the largest pre-Pan-African basement complex of northern Namibia (Brandt et al., 2003) and constitutes the southwestern margin of the Archean to Paleoproterozoic Congo Craton. The EC consists of high-grade metamorphic, widely migmatized ortho-and paragneisses and was intruded by the 1385-1319 Ma Kunene Intrusive Co...
Conference Paper
Fe isotopes provide a promising tool to trace fluid-rock interactions and mass transfer in subducting oceanic lithosphere due to redox-sensitive isotope fractionation (phases rich in Fe3+ preferentially incorporate the heavier isotopes). Our study aims at understanding to which extent the Fe isotope signatures of eclogites reflect (1) igneous proto...
Article
Full-text available
In situ chalcophile and siderophile major and trace elements were analyzed in sulfides from eight Moroccan Middle Atlas lherzolite xenoliths using electron microprobe and laser ablation inductively coupled plasma mass spectrometry. The sulfides occur enclosed in primary silicates, interstitial in the peridotite matrix, and associated with glass-bea...
Article
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Greece hosts a variety of magmatic-hydrothermal ore deposits/prospects with porphyry- and epithermal styles playing a major role in its total gold endowment. These deposit types are mainly clustered in two areas, the Rhodope- and Attico-Cycladic massifs, and formed from about 33 Ma to the Pleistocene, as a result of back-arc extension in the Aegean...
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...