Aragonite pseudomorphs in high-pressure marbles of Syros, Greece

Brady, John B.; Markley, Michelle; Schumacher, John C.; Cheney, John T.; Bianciardi, Grace A

doi:10.1016/s0191-8141(03)00099-3

Cited by 53 publications

(52 citation statements)

References 19 publications

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“…In the pure calcite layers, single grains of elongate calcite (rods) are aligned in a columnar texture that is typically at a high angle to the foliation defined by mica flakes (Figure 4(A)). This columnar texture is interpreted to indicate pseudomorphs of calcite after aragonite (Brady, Markley, Schumacher, Cheney, & Biancardi, 2004;Seaton et al, 2009).…”

Section: Marblementioning

confidence: 99%

Quartz and calcite microfabric transitions in a pressure and temperature gradient, Sivrihisar, Turkey

2013

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Interlayered quartzite and marble in the southern Sivrihisar Massif, Turkey, record metamorphic conditions ranging from high-pressure/low-temperature through a Barrovian overprint from chlorite-to sillimanite-zone conditions. This sequence was exhumed under transtension, producing macroscopic constrictional fabrics (L-tectonites) during crustal thinning. Quartz microstructures consist of dynamically recrystallized aggregates in the dislocation creep regime dominated by grain boundary migration. Quartz microstructures are relatively constant across the high metamorphic gradient, and crystallographic fabric patterns transition from plane strain to constriction strain. Calcite fabrics are characterized by progressive overprinting of a columnar texture inherited from the high-pressure polymorph aragonite. In the low-temperature Barrovian domain (<400°C), shearing of calcite rods produced a very strong c-axis point maximum. At moderate temperature, calcite rods were partially to totally recrystallized and the strong preferred orientation maintained. At temperature >500°C and high constriction strain, marble has no crystallographic fabric, likely reflecting a transition from dislocation creep to diffusion creep. Phengite in high-pressure/low-temperature marble and quartzite yields relatively simple age spectra with Late Cretaceous 40 Ar/ 39 Ar ages. Barrovian muscovite records significantly younger ages (63-55 Ma). The transtension system and associated metamorphism may have occurred above a subduction zone in Paleocene-Eocene time as a precursor to intrusion of Eocene (~53 Ma) arc plutons.

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Section: Marblementioning

confidence: 99%

Quartz and calcite microfabric transitions in a pressure and temperature gradient, Sivrihisar, Turkey

2013

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“…Hecht, 1984;Dixon and Ridley, 1987;Seck et al, 1996). The petrological, structural and tectono-metamorphic evolution of the island of Syros has been investigated in a large number of studies (Dixon, 1968;Bonneau et al, 1980;Ridley, 1982Ridley, , 1984Ridley, , 1986Ballhaus and Schumacher, 1995;Trotet et al, 2001a;Rosenbaum et al, 2002;Ring et al, 2003;Brady et al, 2004;Keiter et al, 2004). For different rock types, a prograde P-T path was derived, characterised by a high P/T ratio, typical for subduction zone metamorphism.…”

Section: Geologymentioning

confidence: 99%

Partitioning and budget of Li, Be and B in high-pressure metamorphic rocks

Marschall

Altherr

Ludwig

et al. 2006

Geochimica et Cosmochimica Acta

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Partitioning and budget of Li, Be and B in high-pressure metamorphic rocks from the island of Syros (Greece) were studied, using secondary ion mass spectrometry, inductively coupled plasma optical emission spectrometry and prompt gamma neutron activation analysis. Partitioning between coexisting mineral phases was found to be rather constant and independent of element concentrations. For several mineral pairs, apparent partition coefficients vary in a narrow range, while concentrations vary by more than an order of magnitude. Hence, it was possible to establish sets of inter-mineral partition coefficients for Li, Be and B among 15 different high-pressure minerals. This data set provides important information on the behaviour of the light elements in different lithologies within subducting slabs from the onset of metamorphism to the eclogite stage. It is essential for modelling trace-element and isotope fractionation during subduction and dehydration of oceanic crust.

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“…Dixon 1968;Ridley 1984;Rosenbaum et al 2002;Brady et al 2004;Keiter et al 2004;Forster and Lister 2005;Bröcker and Keasling 2006 Fig. 1 Simplified geological map of the northern part of Syros (after Keiter et al 2004).…”

Section: Geology Of Syros and Occurrence Of Tourmalinementioning

confidence: 99%

Detrital, metamorphic and metasomatic tourmaline in high-pressure metasediments from Syros (Greece): intra-grain boron isotope patterns determined by secondary-ion mass spectrometry

Marschall

Altherr

Kalt

et al. 2007

Contrib Mineral Petrol

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The boron isotopic composition of zoned tourmaline in two metasediments from the island of Syros, determined by secondary-ion mass spectrometry (SIMS), reflects the sedimentary and metamorphic record of the rocks. Tourmaline from a silicate-bearing marble contains small (B20 lm) detrital cores with highly variable d11 B values (-10.7 to +3.6%), pointing to a heterogeneous protolith derived from multiple sources. The sedimentary B isotopic record survived the entire metamorphic cycle with peak temperatures of *500°C. Prograde to peak metamorphic rims are homogeneous and similar among all analysed grains (d 11 B & +0.9%). The varying d 11 B values of detrital cores in the siliceous marble demonstrate that in situ B isotope analysis of tourmaline by SIMS is a potentially powerful tool for provenance studies not only in sediments but also in metasediments. A meta-tuffitic blueschist bears abundant tourmaline with dravitic cores of detrital or authigenic origin (d 11 B & -3.3%), and prograde to peak metamorphic overgrowth zones (-1.6%). Fe-rich rims, formed during influx of B-bearing fluids under retrograde conditions, show strongly increasing d11 Bvalues (up to +7.7%) towards the margins of the grains. The d 11 B values of metamorphic tourmaline from Syros, formed in mixed terrigenous-marine sediments, reflect the B signal blended from these two different sources, and was probably not altered by dehydration during subduction.

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Aragonite pseudomorphs in high-pressure marbles of Syros, Greece

Cited by 53 publications

References 19 publications

Quartz and calcite microfabric transitions in a pressure and temperature gradient, Sivrihisar, Turkey

Quartz and calcite microfabric transitions in a pressure and temperature gradient, Sivrihisar, Turkey

Partitioning and budget of Li, Be and B in high-pressure metamorphic rocks

Detrital, metamorphic and metasomatic tourmaline in high-pressure metasediments from Syros (Greece): intra-grain boron isotope patterns determined by secondary-ion mass spectrometry

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