Esther Schmädicke

Esther Schmädicke
Friedrich-Alexander-University of Erlangen-Nürnberg | FAU · Department of Geography and Earth Sciences

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58
Publications
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1,491
Citations
Citations since 2016
14 Research Items
618 Citations
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120

Publications

Publications (58)
Article
Full-text available
This study presents new secondary ion mass spectrometry (SIMS) reference materials (RMs) for measuring water contents in nominally anhydrous orthopyroxenes from upper mantle peridotites. The enstatitic reference orthopyroxenes from spinel peridotite xenoliths have Mg#s between 0.83 and 0.86, Al2O3 ranges between 4.02 and 5.56 wt%, and Cr2O3 ranges...
Article
Full-text available
Major and trace elements in omphacite, including hydrogen, were determined in eclogites from two Variscan basement complexes in Germany: Erzgebirge (EG) and Fichtelgebirge (FG). Erzgebirge eclogite is derived from three units, showing different peak pressure (P) and temperature (T) conditions (Unit 1: 840–920 °C/≥30 kbar, Unit 2: 670–730 °C/24–26 k...
Article
New zircon U-Pb-Hf-O isotope, whole rock geochemical and Sr-Nd-Pb isotope geochemical data of Variscan felsic to intermediate rocks from the Odenwald-Spessart basement, Mid-German Crystalline Zone, Germany are presented. Peraluminous, high-K calc-alkaline S-type granite in the eastern Odenwald basement (Group 1 rocks) formed by partial melting of t...
Article
Full-text available
Orthopyroxene was analyzed as a proxy for water supra-subduction-zone peridotite by polarized infrared radiation. Samples from Conical and Torishima seamounts, Mariana-Izu-Bonin forearc (ODP-Leg 125), have very similar average H2O contents of 215 ppm (range: 122–363 ppm; Conical) and 191 ppm (range: 116–292 ppm; Torishima). Conical peridotite equil...
Article
Meta-basaltic eclogite occurs in the Erzgebirge in three high-pressure (HP) units (Unit 1, 2, and 3) as numerous lenses within high-grade felsic rocks. Units 2 and 3 are common HP units with quartz eclogite, and Unit 1 is an ultra-high pressure (UHP) unit with coesite eclogite, garnetite (metarodingite) and garnet peridotite. The conditions of peak...
Article
Full-text available
Little is known about water in nominally anhydrous minerals of orogenic garnet peridotite and enclosed metabasic rocks. This study is focused on peridotite‐hosted eclogite and garnetite (metarodingite) from the Erzgebirge (EG), Germany, and the Lepontine Alps (LA), Switzerland. Newly discovered, peridotite‐hosted eclogite in the Erzgebirge occurs i...
Article
Erzgebirge eclogite occurs in three high-pressure (HP) units, including one UHP unit (Unit 1). Each sample investigated contains either magmatic or metamorphic zircon but never both. This is in contrast to many literature examples of eclogite with more than one generation of zircon. We infer that metamorphic zircon formed at the expense of a magmat...
Article
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Evidence for the heterogeneity of the mantle's water content is generally acknowledged but it remains unclear if the variability of data is influenced by decompressional water loss. Here based on high water contents in peridotite, we explore if water gain may play a role. The study investigates water in abyssal peridotite by analyzing oriented orth...
Article
New geochronological data reveal a prolonged tectonothermal evolution of the Variscan Odenwald-Spessart basement, being part of the Mid-German Crystalline Zone in central Europe. We report the results from (i) secondary ion mass spectrometry (SIMS) U-Pb dating of zircon, rutile and monazite, (ii) SIMS zircon oxygen isotope analyses, (iii) laser abl...
Article
The water content of garnet was determined for eclogite from two Variscan complexes in Germany: the Erzgebirge (EG), Saxony, and the Fichtelgebirge (FG), Bavaria. Erzgebirge eclogites occur in three units, each of which experienced specific peak conditions (unit 1: 840-920°C/ ≥ 30 kbar, unit 2: 670-730°C/24-26 kbar, unit 3: 600-650°C/20-22 kbar). P...
Article
Full-text available
A key question concerning the water budget of Earth's mantle is how much water is actually recycled into the mantle by the subduction of eclogitized oceanic crust. Hydrous phases are stable only in quartz eclogite not coesite eclogite so that water transport to greater depths is mainly governed by structural water in omphacite and garnet. Here we e...
Article
Full-text available
New in situ electron microprobe monazite and white mica 40Ar/39Ar step heating ages support the proposition that the Odenwald–Spessart basement, Mid-German Crystalline Zone, consists of at least two distinct crustal terranes that experienced different geological histories prior to their juxtaposition. The monazite ages constrain tectonothermal even...
Article
Garnets from kimberlite-hosted mantle and a few xenoliths from the lower crust were investigated for water, major, minor, and trace elements. Xenoliths from the mantle comprise pyroxenite, eclogite, alkremite, and peridotite, and crustal xenoliths are mafic high-pressure granulites. Samples from South Africa, Lesotho, and Namibia comprise two princ...
Article
Lenses of ultramafic rocks occur in supracrustal high-grade gneiss in the northern Haskard Highlands, Shackleton Range, East Antarctica. Olivine-bearing garnet pyroxenite is the dominant rock type that is associated with hornblendite and subordinate spinel peridotite and amphibolite. The high-pressure (23-25. kbar) garnet-olivine assemblage of the...
Article
Abyssal spinel peridotites from Hess Deep, East Pacific Rise (ODP Leg 147) were investigated concerning their major, minor, and trace element mineral chemistry and the incorporation of structural water in orthopyroxene.
Article
Full-text available
Nephrite is a kind of valuable jade which forms during metamorphism under greenschist facies conditions. Most investigations focus on the genesis of nephrite, however, the formation age of nephrite remains poorly constrained due to the lack of suitable dating methods. In this paper, the petrological, chemical characteristics, and mineral inclusions...
Article
The Mid-German Crystalline Zone is part of a large Variscan suture and consists of various basement complexes that are exposed in central Germany. New lithogeochemical and Sr-Nd-Pb isotope data obtained on various amphibolites from the Odenwald-Spessart basement show that their protoliths formed in different tectonic settings and were subsequently...
Article
Full-text available
Traces of water in mantle minerals strongly influence mantle melting and viscosity that, in turn, governs large-scale processes like mantle convection, plate tectonics, and the stabilization of cratons. One way of estimating the mantle's water content is by analyzing mantle xenoliths brought to the Earth's surface. A major problem in estimating the...
Article
Orthopyroxene (opx) in oceanic spinel peridotite is a useful proxy for water contents in the sub-oceanic mantle. Because of its large grain size (compared to olivine), opx is less affected by secondary diffusional water loss due to decompression. Contrasting water contents were found in opx of oceanic spinel peridotite, comparing samples from the M...
Article
Full-text available
The major and minor element compositions and textures of white nephrite samples from 6 different deposits including Xiaomeiling district (Jiangsu province, China), Luanchuan district (Henan province, China), Hetian district (Xinjiang province, China), Geermu district (Qinghai province, China), Chuncheon district (Korea) and Baikal district (Russia)...
Article
Precambrian Research j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / p r e c a m r e s Garnet pyroxenite, eclogite and alkremite xenoliths from the off-craton Gibeon Kimberlite Field, Namibia: A window into the upper mantle of the Rehoboth Terrane a b s t r a c t Different types of mantle xenoliths, including garnet...
Article
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Earlier studies on xenolithic mantle rocks imply that the water contents originally present in the minerals at mantle depth may survive despite uplift and decompression. This study addresses the question if mantle minerals in slowly exhumed peridotites that are partially replaced by secondary hydrous phases still retain the original defect water co...
Article
Orthopyroxene in oceanic spinel peridotite from the Mid-Atlantic Ridge near 15°N, ODP-Leg 209, contains about 15 wt.-ppm water that is bound as hydroxyl in the mineral structure. This value is one order of magnitude lower than the water contents reported for (i) orthopyroxene in peridotite from the Mid-Atlantic Ridge at 23°N (270 wt.-ppm), ODP-Leg...
Article
A petrological investigation of abyssal, plagioclase-free spinel peridotite drilled during ODP cruise 153 in the North Atlantic revealed that the peridotite represent refractory, partial residual mantle material that experienced depletion of incompatible trace elements during upper mantle melting. The degree of partial melting as estimated from spi...
Article
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Three distinct, spatially separated crustal terranes have been recognised in the Shackleton Range, East Antarctica: the Southern, Eastern and Northern Terranes. First insights into the origin and evolution of critical units from these terranes could be gained from new lithogeochemical and isotope (Rb–Sr, Sm–Nd, Pb–Pb whole rock and Lu–Hf zircon) da...
Article
Garnet-bearing ultramafic rocks (GBUR) enclosed in granulite or high-grade gneiss are rare, yet typical constituents of alpine-type collisional orogens. The Bohemian Massif of the European Variscides is exceptional for the occurrence of a large variety of mantle-derived rocks, including GBUR (garnet peridotite and garnet pyroxenite). GBUR occur in...
Data
Three distinct, spatially separated crustal terranes have been recognised in the Shackleton Range, East Antarctica: the Southern, Eastern and Northern Terranes. Mafic gneisses from the Southern Terrane provide geochemical evidence for a within-plate, probably back-arc origin of their protoliths. A plume-distal ridge origin in an incipient ocean bas...
Article
Full-text available
A comprehensive set of new geochronological data from different parts of the Shackleton Range in East Antarctica, comprising U–Pb single zircon and Th–U–Pb single and multi-grain monazite data, combined with published results, reveal a complex tectono-thermal history of the Shackleton Range. Three distinct, spatially separated terranes or units wit...
Article
Full-text available
We present the first water concentration data for oceanic mantle peridotite. The rocks come from the Mid-Atlantic Ridge and were sampled by drilling during Leg 153 of the Ocean Drilling Program. Earlier studies of peridotite xenoliths suggest that orthopyroxene is the most important host of water in the upper mantle. However, an unresolved question...
Article
Full-text available
The infrared (IR) spectra of gem-quality olivine crystals from Pakistan, formed in serpentinised dunitic rocks, are characterised by strongly pleochroic absorption bands at 3,613, 3,597, 3,580 and 3,566cm−1. These bands are assigned to O-H stretching vibrations of OH point defects corresponding to H2O concentrations of about 35wtppm. Unlike other o...
Article
In the Shackleton Range of East Antarctica, garnet-bearing ultramafic rocks occur as lenses in supracrustal high-grade gneisses. In the presence of olivine, garnet is an unmistakable indicator of eclogite facies metamorphic conditions. The eclogite facies assemblages are only present in ultramafic rocks, particularly in pyroxenites, whereas other l...
Data
In the Shackleton Range of East Antarctica, garnet-bearing ultramafic rocks occur as lenses in supracrustal high-grade gneisses. In the presence of olivine, garnet is an unmistakable indicator of eclogite facies metamorphic conditions. The eclogite facies assemblages are only present in ultramafic rocks, particularly in pyroxenites, whereas other l...
Article
Full-text available
Here we present water concentration data for olivine from different host rocks, measured with a nuclear technique using proton-proton scattering. This method, which is used here for the first time on olivine, is very powerful for determining trace amounts of water. The studied olivine specimens differ in their H2O contents, ranging from 4 to 51 wt...
Article
Abstract The Erzgebirge Crystalline Complex (ECC) is a rare example where both‘crustal’eclogites and mantle-derived garnet-bearing ultramafic rocks (GBUs) occur in the same tectonic unit. Thus, the ECC represents a key complex for studying tectonic processes such as crustal thickening or incorporation of mantle-derived material into the continental...
Article
Full-text available
The Shackleton Range in East Antarctica is part of the Pan-African collisionall orogen related to the convergence between East and West Gondwana. In the northern Shackleton Range, alpine-type ultramatic rocks occur as lenses in high-grade gneisses. These include peridotite and pyroxenite that contain garnet and/or spinell in addition to olivine, or...
Article
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The blueschist and greenschist units on the island of Sifnos, Cyclades were affected by Eocene high-pressure (HP) metamorphism. Using conventional geothermobarometry, the HP peak metamorphic stage was determined at 550–600 °C and 20 kbar, close to the blueschist and the eclogite facies transition. The retrograde P–T paths are inferred with phase di...
Article
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Mineral assemblages in Al2O3-rich, SiO2- and K2O-poor metapelitic rocks from the western Odenwald Crystalline Complex (Variscan Mid-German Crystalline Rise, southern Germany) include corundum, spinel, cordierite, sillimanite, garnet and staurolite. Quartz is absent from almost all samples. Therefore, the applicability of conventional geothermobarom...
Article
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A metamorphosed ultramafic rock, penetrated by the KTB pilot hole at a depth of 1382.36 m, contains the assemblage Caamphibole - anthophyllite - chlorite - talc, formed at about 630degreesC/10 kbar under conditions of the high-P amphibolite facies. EMP analyses of the Ca-amphibole yielded magnesiohastingsite (to pargasite) compositions with (Al+Fe3...
Article
Metabasic rocks were recently found in the Böllsteiner Odenwald, being part of the Variscan Mid-German Crystalline Rise (MGCR), that give evidence of a so far unrecognised eclogite-facies metamorphic event and testify, for the first time, to high-pressure metamorphism in the MGCR, the assumed suture zone of the European Variscides. Eclogite-facies...
Article
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Summary In the Odenwald Crystalline Complex, calc-silicate rocks are concentrated at the margins of the marble layer of Auerbach. They were presumably formed by metasomatic exchange between the calcite marble and the neighbouring granodioritic and quartz-dioritic intrusives. The investigated samples contain the characteristic mineral assemblages: g...
Article
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In the Erzgebirge Crystalline Complex, eclogites occur in three different high pressure (HP) units (1, 2 and 3) recording contrasting pressure (P)–temperature (T) conditions. Eclogites from HP-unit 1 experienced peak metamorphic conditions in the coesite stability field at about 33 kbar/850 °C. Commonly, these eclogites from HP-unit 1 are all very...
Article
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Alpine-type peridotites and associated pyroxenites are found as lenses in the continental crust in many different orogens. The reconstruction of the pressure–temperature ( P – T ) evolution of these rocks is, however, difficult or even impossible. With geothermobarometry, usually one point on the overall P – T path can be obtained. To use the diffe...
Article
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Calculated phase equilibria among the minerals sodic amphibole, calcic amphibole, garnet, chloritoid, talc, chlorite, paragonite, margarite, omphacite, plagioclase, carpholite, zoisite/clinozoisite, lawsonite, pyrophyllite, kyanite, sillimanite, quartz and H2O are presented for the model system Na2O-CaO-FeO-MgO-Al2O3-SiO2-H2O (NCFMASH), which is re...
Article
In the Proterozoic Schist Belt of Nigeria, lenticular bodies of metabasites and meta-ultramafics are frequently intercalated within staurolite bearing metapelitic schists. Such a metamorphosed mafic-ultramafic complex is particularly well exposed in the Mokuro riverbed between the towns of Ife and Ilesha. These outcrops display contact relationship...
Article
amphibole, calcic amphibole, garnet, chlor- itoid, talc, chlorite, paragonite, margarite, omphacite, plagioclase, , /clinozoisite, lawsonite
Article
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Garnet-bearing ultramafic rocks (GBU) enclosed in high-grade gneisses are known from several parts of the Bohemian Massif. One of these is the high-pressure(HP)-unit 1 in the Erzgebirge Crystalline Complex, which is the subject of the present study. Hitherto, two different models have been put forward to explain the stabilisation of garnet in mantl...
Article
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&#112Lenses of ultramafic rocks intercalated within a metagabbro–amphibolite sequence were encountered in the KTB pilot hole. A pervasive metamorphic overprint formed the dominating assemblage calcic amphibole–orthoamphibole–chlorite–talc. In this study the phase relations of ultramafic rocks are investigated in order to (a) constrain the stability...
Article
Petrological investigations are directed to recognise the polymetamorphic evolution of the Erzgebirgian eclogites. Detailed micropetrographic investigations of reaction and growth textures constrain the succession of mineral assemblages and mineral reactions, thus deciphering the polymetamorphic evolution of the eclogites and, partly, of their coun...
Article
The differences in the PT-estimates derived from various lithologies of the same geologic unit in the Munchberg Gneiss Complex (MGC) and the Erzgebirge Crystalline Complex (ECC) do not necessarily imply contrasting thermochronologic histories and a subsequent tectonic juxtaposition, but may be the result of reaction kinetics. The stabilisation, pre...
Article
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The metamorphic sequences of the Saxonian Erzgebirge were thoroughly overprinted by a Variscan medium-pressure event under amphibolite facies conditions. However, eclogitic relics documenting an older high-pressure event are widespread. P-T conditions of the eclogite-facies metamorphism systematically decrease, over a distance of 50 km, from about...
Article
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Eclogites are intercalated in gneisses in the central and western Erzgebirge. Petrographically, they show a regional zonation from E (Floha Syncline) to W (Oberwiesenthal) with respect to the primary mineralogy, retrograde reactions and textures. Probable quartz pseudomorphs after coesite are described as inclusions in omphacite and garnet in the F...
Article
Full-text available
62 quartz specimens of pegmatites of economic significance from Mozambique, Namibia, Zimbabwe, Brasilia, Canada, Mongolia, the Soviet Union, Greenland, Norway, Sweden, Spain, the Federal Republic of Germany as well as of various types of granite- and rhyolite-quartz from the German Democratic Republic have been subjected to complex geochemical inve...

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Project (1)
Project
The main motivation of this long-term project is to delineate the geodynamic history of the Mid-German Crystalline Zone (MGCZ) in the course of the Variscan orogeny by a combination of petrological, structural, geochemical and geochronological studies. The Mid-German Crystalline Zone is thought to have formed during the late Variscan closure of the Rheic Ocean and should contain the associated Variscan suture (Rheic Suture). Recent exciting results showed that the Odenwald-Spessart basement, which is the largest outcrop area of the MGCZ hosts a paired metamorphic belt with high-pressure eclogite-facies rocks situated next to high-temperature granulite-facies rocks being separated by the Rheic Suture. Further research is in progress.