Petrogenesis and geotectonic setting of ultramafic rocks in the Eastern Alps: constraints from geochemistry

Melcher, Frank; Meisel, Thomas; Puhl, J.; Koller, F

doi:10.1016/s0024-4937(02)00161-5

Cited by 92 publications

(73 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 Zr versus Cr, and Zr versus Yb plots of serpentinite, talc (± amphibole) and chlorite schists and mafic rocks from the Pouébo Eclogite Mélange. Fields for abyssal peridotite are from data from Melcher et al (2002) and Niu (2004). PEM Pouébo Eclogite Mélange Ce anomalies that are similar to those observed in the serpentinite (Fig.…”

Section: Talc Schistmentioning

confidence: 84%

The importance of talc and chlorite “hybrid” rocks for volatile recycling through subduction zones; evidence from the high-pressure subduction mélange of New Caledonia

Spandler

Hermann

Faure

et al. 2007

Contrib Mineral Petrol

157

111

View full text Add to dashboard Cite

The transfer of fluid and trace elements from the slab to the mantle wedge cannot be adequately explained by simple models of slab devolatilization. The eclogite-facies mélange belt of northern New Caledonia represents previously subducted oceanic crust and contains a significant proportion of talc and chlorite schists associated with serpentinite. These rocks host large quantities of H 2 O and CO 2 and may transport volatiles to deep levels in subduction zones. The bulk-rock and stable isotope compositions of talc and chlorite schist and serpentinite indicate that the serpentinite was formed by seawater alteration of oceanic lithosphere prior to subduction, whereas the talc and chlorite schists were formed by fluid-induced metasomatism of a mélange of mafic, ultramafic and metasedimentary rocks during subduction. In subduction zones,

show abstract

Section: Talc Schistmentioning

confidence: 84%

The importance of talc and chlorite “hybrid” rocks for volatile recycling through subduction zones; evidence from the high-pressure subduction mélange of New Caledonia

Spandler

Hermann

Faure

et al. 2007

Contrib Mineral Petrol

157

111

View full text Add to dashboard Cite

show abstract

“…While TiO 2 contents of the clinopyroxenes in the wehrlite and websterite range from 0.21 to 0.43, those of the clinopyroxenite sample are between 0.53 and 0.90. These compositional properties, especially for Al 2 O 3 and TiO 2 , of pyroxene minerals are very similar to those of pyroxene minerals in pleonaste-bearing rocks from the Eastern Alps (e.g., Melcher et al, 2002).…”

Section: Mineral Chemistrymentioning

confidence: 52%

Origin of the pleonaste-bearing mafic-ultramafic rocks from the Armutlu peninsula, NW Turkey

Özkan¹,

Çelik²

2018

Turkish J Earth Sci

View full text Add to dashboard Cite

IntroductionSpinel-group minerals (general formula: AB 2 O 4 ) are important geological tools to understand the petrogenetic properties and geodynamic environment of the rocks in which they occur in a wide compositional range (e.g., Dick and Bullen, 1984;Arai et al., 2011). Spinel (MgAl 2 O 4 ) and hercynite (Fe 2+ Al 2 O 4 ) solid-solution series are the aluminum-rich (Al-rich) two end-members of spinelgroup minerals. They rarely occur as pure end-members in nature and if the substitution ratio of divalent Mg 2+ and Fe 2+ in these end-members is from 3 to 1, the mineral is called pleonaste [(Mg 0.25-0.75 Fe 0.25-075 )Al 2 O 4 ] (Deer et al., 1992). In the present study Al-rich spinel is used as a general name for spinel, hercynite, and pleonaste. The Al-rich spinel solid solution series have been observed in the amphibolite-granulite facies basic-ultrabasic and pelitic rocks, the basic-ultrabasic magmatic rocks, and the mantle xenoliths in volcanic rocks (e.g.

show abstract

“…In addi- Alpine-type ultramafites (Melcher et al 2002) tion, both Mg# and Ni contents of the GS olivine are rather close to those typical of the mantle-derived olivine (Brown 1980;Takahashi et al, 1987) in ophiolitic peridotites (e.g. Niida 1997;Pearce et al 2000).…”

Section: Upper Mantle Stage -The Composition Of the Protolithmentioning

confidence: 85%

“…Höck et al 1997;Gunia et al 1998;Medaris et al 2005) and Mesozoic Alpine complexes (e.g. Melcher et al 2002). Field studies demonstrated that serpentine minerals (firstly lizardite, chrysotile and antigorite) are the major constituents of the metamorphosed ultramafic rocks in the Alpine ophiolites (Trommsdorff and Evans 1974;Piccardo et al 1980;Lemoine et al 1987;Lagabrielle and Cannat 1990).…”

Section: Introductionmentioning

confidence: 99%

Petrologic comparison of the Gyód and Helesfa serpentinite bodies (Tisia Mega Unit, SW Hungary)

Kovács¹,

Radovics²,

Tóth³

2016

J. Geosci.

View full text Add to dashboard Cite

Magnetic anomalies in the south-western part of the Tisia Mega Unit were drilled in different geological situations: the Helesfa serpentinite body is surrounded by a Variscan granite, while the host rocks of the Gyód serpentinite body are paragneiss and amphibolite. Nevertheless, these anomalies are on opposite sides of the Mecsekalja Shear Zone, which developed during the Variscan Orogeny. Olivine, enstatite and spinel occur as relicts in the Gyód serpentinite, while the primary ultramafic rock of the Helesfa serpentinite is totally serpentinized. Based on the major-element whole-rock geochemical data, the protolith of the two serpentinites was mainly harzburgite. Based on the similar petrography, textures, mineral composition, major-element geochemistry, as well as metamorphic and structural evolution, a close genetic relationship between the Gyód and Helesfa serpentinite bodies can be supposed. Serpentinite with pseudomorphous lizardite and chrysotile textures possibly formed during the ocean-floor metamorphism. Afterwards, an antigorite ± talc assemblage developed from the pseudomorphous serpentine texture, which is sheared and mylonitized, supposedly due to subduction. Serpentinites with similar composition and evolution are widespread in the Bohemian Massif (especially in the Polish Central-Sudetic ophiolites).Keywords: serpentinite, harzburgite, websterite, Alpine-type ophiolite, Tisia, Variscides Received: 5 March, 2016; accepted: 30 September, 2016; handling editor: E. Jelínek magnetic, aeromagnetic and aero-gamma surveys, small local anomalies were recorded, which were drilled by exploration boreholes in some cases. In this way, the Gyód serpentinite (GS) and Helesfa serpentinite (HS) bodies were recognized in the crystalline basement of SW Tisia Mega Unit (Fülöp 1994). During geological exploration, a third, Ófalu serpentinite body (OS) was identified (Ghoneim and Ravasz-Baranyai 1969).The early petrographic and geochemical analyses (Ghoneim and Ravasz-Baranyai 1969;Erdélyi 1974;Szederkényi 1974Szederkényi , 1976bSzederkényi , 1977Szederkényi and Grasselly 1977; Ghoneim 1978;Jantsky 1979;Ghoneim and Szederkényi 1979;Svingor and Kovách 1981;Balla 1981Balla , 1983Balla , 1985Papp 1989) led to different opinions regarding the protoliths, metamorphic evolution and genesis of the two serpentinite bodies. Petrographic, mineralogical and geochemical comparison of the Gyód and Helesfa serpentinites, based on the available drill cores, is presented in this work. A detailed evaluation of the likely protoliths, metamorphic evolution as well as deformation history of both bodies may serve as a firm basis to delineate a uniform evolution scheme for the study area. In the future, this approach would provide data for comparisons with other serpentinite bodies in the vicinity and thus the Tisia Mega Unit's evolution.

show abstract

Petrogenesis and geotectonic setting of ultramafic rocks in the Eastern Alps: constraints from geochemistry

Cited by 92 publications

References 68 publications

The importance of talc and chlorite “hybrid” rocks for volatile recycling through subduction zones; evidence from the high-pressure subduction mélange of New Caledonia

The importance of talc and chlorite “hybrid” rocks for volatile recycling through subduction zones; evidence from the high-pressure subduction mélange of New Caledonia

Origin of the pleonaste-bearing mafic-ultramafic rocks from the Armutlu peninsula, NW Turkey

Petrologic comparison of the Gyód and Helesfa serpentinite bodies (Tisia Mega Unit, SW Hungary)

Contact Info

Product

Resources

About