Bergell Pluton, Central Alps
Published:
Mechanisms and timescales of pluton emplacement
Publications: Samperton et al., 2015, Samperton et al., 2017
K-feldspar megacrysts entrained in a mafic enclave, Forno region
Recently deglaciated exposure is sufficiently fresh that oxidation of exposed pyrite is still ongoing.
Dense clot of K-feldspar megacrysts, Forno region
Strongly foliated amphibolite xenoliths near the roof of the Bergell pluton, Forno region
Amphibolite xenolith with calc-silicate affinities (note epidote and calcite veins) near the roof of the Bergell pluton, Forno region
Extensive exposure of the megacrystic K-feldspar granodiorite facies of the Bergell Pluton near Albigna
The spire of Piz. Badile, glacially carved out of Bergell granodiorite, Sciora region
A large mafic enclave cut and offset by an aplite dike, Sciora region
Mafic enclave diced by two small magmatic shear zones, Sciora region
Nearly hexagonal mafic enclave, Sciora region
Dust rises from an active rockfall on Piz. Cengalo, Sciora region
An aplite “schlieren-dike” offset across a magmatic shear zone in the transitional “übergangszone” facies of the Bergell pluton, Sciora region
Heterogeneous enclave swarm in the Bergell übergangszone, Sciora region
Poikilitic garnet and tourmaline crystals in a pegmatite dike, Sciora region
Large mafic enclave swarm in the Bergell übergangszone, Sciora region
K-feldspar megacryst entrained and partially resorbed within mafic enclave, Sciora region
Deformed mafic enclaves in an enclave swarm, übergangszone, Sciora region
Ultramafic xenoliths in Bergell granodiorite, altered to anthophyllite and biotite, Sciora region
Dense K-feldspar megacryst clot with biotite-rich interstices, Gianetti region. Ruler is set to 1m for scale.
Large aplite dike, Gianetti region. One of many striking roughly ~240 throughout the Bergell pluton. Kyle Samperton for scale.
Close-packed K-feldspar megacryst clot offset by otherwise-invisible magmatic shear zone, Gianetti region. Note marked concentration of biotite at margin.
Detail of megacryst clot, Gianetti region
Altered ultramafic xenolith, progresively retrograded to chlorite (center) and biotite (rim). Allievi region.
Discordant magmatic contact cut by composite aplite-pegmatite dike, Kima region
Bergell tonalite scattered with ultramafic talus fallen from Monte Disgrazia
Deformed quartz veins following a classic conjugate fracture pair, Ponti region
Discordant contact revealed by strong magmatic fabrics, Ponti region
Sharp contact of Bergell tonalite with shear zone at roof of pluton, Ponti region
Calc-silicate boudin in marble country rock near the roof of the Bergell pluton, Ponti region
