P–T–t Evolution of Ultrahigh-Temperature Granulites from the Saxon Granulite Massif, Germany. Part II: Geochronology

Romer, Rolf L.; Rötzler, Jochen

doi:10.1093/petrology/42.11.2015

Cited by 60 publications

(42 citation statements)

References 55 publications

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“…However, if the zircon ages of c. 340 Ma in these granulites do correspond to the peak granulite facies conditions [7], and the 40 Ar/ 39 Ar mica cooling cooling ages are within the range of 330-340 Ma [60], the exhumation rate of the Śnieżnik granulites would have to be by an order of magnitude higher. A similar scenario of extremely fast exhumation (10-15 mm/year) is known from the 340 Ma granulites of the Granulitgebirge [12] and Erzgebirge [2,3].…”

Section: Timing Of P-t Paths In the Granulitessupporting

confidence: 52%

“…They display a range of PT peak metamorphic conditions (exceeding 1000 o C and 20 kbar in several cases), and various isotopic ages, with two distinct, albeit broadly defined groups at c. 400 and 340 Ma [e.g., 4,[10][11][12]. Originally, the older granulites were interpreted as related to the subduction of continental crust, whereas the younger ones were regarded as products of deep crustal processes connected with collision during the Variscan orogeny [1].…”

Section: Introductionmentioning

confidence: 99%

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Devonian deep-crustal metamorphism and exhumation in the Variscan Orogen: evidence from SHRIMP zircon ages from the HT-HP granulites and migmatites of the Góry Sowie (Polish Sudetes)

Kryza

Fanning

2007

Geodinamica Acta

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The high-temperature and high-pressure granulites in the internal zone of the Variscan belt are witnesses of deep crustal processes and subsequent exhumation of deeper lithospheric fragments. The Góry Sowie Block granulites in SW Poland and the surrounding gneisses and migmatites contain different inherited zircon age spectra, testifying different sources of their protoliths: mainly Cadomian (ca. 580 Ma) igneous rocks, and early Ordovician (ca. 500 Ma) granitoids (or their reworked products), respectively. The metamorphic spheric and oval zircons in the granulites give two statistically distinct ages of c. 395 and 380 Ma, in excess of experimental uncertainty. These ages may correspond to the high-temperature (HT) and high-pressure (HP) granulite facies metamorphism and subsequent amphibolite facies retrogression. However, essentially isochemical reconstitution of zircons and inheritance of radiogenic Pb cannot yet be excluded. The retrogression in the granulites coincided with the amphibolite facies metamorphism in the surrounding gneisses evidenced by a range of various isotopic ages between 384 and 370 Ma. The new SHRIMP zircon data provide new evidence of the presence of "old" (c. 400-395 Ma) HT-HP granulites in the central European part of the Variscides. The granulites were subsequently exhumed to mid-crustal levels, and tectonically interleaved with gneisses. Continuing uplift and decompression caused migmatization in the surrounding gneisses and partial re-equilibration of the granulites, at around 380 Ma. This high-temperature and medium-pressure (HT-MP) event was followed by rapid uplift and exhumation at c. 360 Ma due to Eo-Variscan orogenic movements.

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Section: Timing Of P-t Paths In the Granulitessupporting

confidence: 52%

Section: Introductionmentioning

confidence: 99%

Devonian deep-crustal metamorphism and exhumation in the Variscan Orogen: evidence from SHRIMP zircon ages from the HT-HP granulites and migmatites of the Góry Sowie (Polish Sudetes)

Kryza

Fanning

2007

Geodinamica Acta

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“…Our Re-Os molybdenite age is in good agreement with this CHIME age for the same pluton, which was interpreted as recording cooling to about 700ºC (Suzuki and Adachi, 1998). This temperature is in agreement with high closure temperature estimates for U-Pb systematics in monazite (e.g., Romer and Rötzler, 2001;Bingen and van Breemen, 1998).…”

Section: Results and Interpretationsupporting

confidence: 89%

Re-Os age of molybdenite from the Busetsu two-mica granite, central Japan.

舜三

.シュタイン

亮吏

2002

Bull. Geol. Surv. Japan

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“…We chose to analyze monazites because this mineral generally does not contain inherited cores and does not suffer radiogenic Pb loss at low temperatures, both common problems in zircons (see Parrish 1990 for discussion). Additionally, the closing temperature of monazite, although slightly lower than that of zircon (for details see Romer and Rötzler 2001), is sufficiently high to maintain the system unperturbed by low-temperature postcrystallization events.…”

Section: U-pb Geochronologymentioning

confidence: 99%

Lower Carboniferous post-orogenic granites in central-eastern Sierra de Velasco, Sierras Pampeanas, Argentina: U–Pb monazite geochronology, geochemistry and Sr–Nd isotopes

Grosse

Söllner

Báez

et al. 2008

Int J Earth Sci (Geol Rundsch)

111

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The central-eastern part of the Sierra de Velasco (Sierras Pampeanas, NW Argentina) is formed by the large Huaco (40 9 30 km) and Sanagasta (25 9 15 km) granite massifs and the small La Chinchilla stock (2 9 2 km). The larger granites intrude into Ordovician metagranitoids and crosscut Devonian (?) mylonitic shear zones, whereas the small stock sharply intrudes into the Huaco granite. The two voluminous granites are biotitic-muscovitic and biotitic porphyritic syeno-to monzogranites. They contain small and rounded tonalitic and quartz-dioritic mafic microgranular enclaves. The small stock is an equigranular, zinnwaldite-and fluorite-bearing monzogranite. The studied granites are silica-rich (SiO 2 [70%), potassium-rich (K 2 O [4%), ferroan, alkali-calcic to slightly calk-alkalic,

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P–T–t Evolution of Ultrahigh-Temperature Granulites from the Saxon Granulite Massif, Germany. Part II: Geochronology

Cited by 60 publications

References 55 publications

Devonian deep-crustal metamorphism and exhumation in the Variscan Orogen: evidence from SHRIMP zircon ages from the HT-HP granulites and migmatites of the Góry Sowie (Polish Sudetes)

Devonian deep-crustal metamorphism and exhumation in the Variscan Orogen: evidence from SHRIMP zircon ages from the HT-HP granulites and migmatites of the Góry Sowie (Polish Sudetes)

Re-Os age of molybdenite from the Busetsu two-mica granite, central Japan.

Lower Carboniferous post-orogenic granites in central-eastern Sierra de Velasco, Sierras Pampeanas, Argentina: U–Pb monazite geochronology, geochemistry and Sr–Nd isotopes

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