· Field program (Neves area): August 25th to 27th
· Lecture program Bruneck (Brunico): August 28th to 31th
Timetable 25-31 August 2017
field course will be held in the Nevessee (Lago di Neves) area (South Tyrol, northeast Italy) and
will address the structural analysis of deformation structures within the
Tauern meta-granitoids. The structures are present on polished outcrops at the
base of the south-eastern Grosser Möseler (Mesule)
1, Fig. 2) that provide spectacular exposures for
structural analysis of 2D deformation geometries. The area is located at
about 2600 m and is reachable by a well-marked track from the Chemnitzerhütte (Rifugio Porro),
at 2419 m. We will stay at this hut, which one reaches along a broad path
from the Nevessee in about 1 hr
45 mins walking time (about a 500 m climb).
· Mancktelow, N.S. and Pennacchioni, G., 2005. The control of precursor brittle fracture and fluid–rock interaction on the development of single and paired ductile shear zones. Journal of Structural Geology 27, 645–661. PDF
· Mancktelow, N.S. and Pennacchioni, G., 2010. Why calcite can be stronger than quartz. Journal of Geophysical Research 115, B01402, doi:10.1029/2009JB006526. PDF
· Pennacchioni, G. and Mancktelow, N.S., 2007. Nucleation and initial growth of a shear zone network within compositionally and structurally heterogeneous granitoids under amphibolite facies conditions. Journal of Structural Geology 29, 1757-1780. PDF
· Mancktelow, N. S., and Pennacchioni, G., 2013. Late magmatic healed fractures in granitoids and their influence on subsequent solid-state deformation. Journal of Structural Geology 57, 81-96.
· Pennacchioni, G., and Mancktelow, N. S., 2013. Initiation and growth of strike-slip faults within intact metagranitoid (Neves area, eastern Alps, Italy). Geological Society of America Bulletin, 125, 1468-1483.
· Pennacchioni, G., Ceccato, A., Fioretti, A.M., Mazzoli, C., Zorzi, F. and Ferretti, P., 2016. Episyenites in meta-granitoids of the Tauern Window (Eastern Alps): unpredictable?Journal of Geodynamics, 101, 73-87.
Students will be taught to analyse:
· the time relationships between the different intrusions of the pre-Alpine protolith;
· the control of structural and compositional heterogeneities on nucleation of shear zones;
· the role of fluids during ductile deformation;
· the kinematic relationships between the different structural element of the deformation network (shear zones and veins);
· the interference between intersecting shear zones;
· geometry and linkage of brittle faults developed during exhumation.
The second part of the school will include a series of lectures The classes will cover the following topics:
1) Solid-state ductile deformations within cooling of
The lecture will describe the solid-state deformation structures developed in different plutons (e.g.: Adamello, Southern Alps, Italy; Mono Pass Intrusive Suite, Sierra Nevada, California) during their cooling. The main focus will be on deformation structures developed at high temperatures (T ≥ 500°C) and the role of structural (joints) and compositional (e.g. dykes) heterogeneities on nucleation of shear zones. The deformation structures in cooling plutons will be compared with those seen during the field excursion in the Tauern metagranitoids in the Neves area. These observations provide the basis of a new model for the nucleation of ductile shear zones in granitoid plutons.
2) Fluid rock interaction in faults and shear zones.
(a) Physical effects of fluids on stregth and mechanical behaviour of faults and shear zones
3) Deformation mechanisms and
strain weakening in natural shear zones.
The lecture will show examples of deformation
microstructures of quartz and feldspars in natural shear zones formed at
mid- to lower-crustal conditions. The observations will be discussed in terms
of (i) the effect of fluid rock interaction on the
activation of different deformation mechanisms, and (ii) the implications for
the strength evolution of the mid- to lower crust. The following topics will
analogue and numerical modelling of shear zone structures.
Strain localization and the development of heterogeneous shear zones
5) Introduction to Finite Element Modelling in Geoscience
6) Deformation of
quartz-rich rocks in nature and experiments
is one of the most important rock-forming mineral and significantly controls the rheology of the Earth's continental crust. Experimentally calibrated piezometer and flow laws
can be used to determine stress and strain rate of naturla deformation if deformation mechanisms are the same in nature and experiments, and if the deformatione temperature is known.
Crystal plastic deformation of quartz covers a wide range of conditions. Based on natural and experimantal data it will be shown that this range can be even wider than commonly expected.
Topics of this lecture are:
6) Role of chemical processes on strain localisation
The aim of this lecture is to discuss the role of metamorphic and metasomatic reactions on the process of strain localisation. Using various natural examples coming from the Alps, including the Neves area, we will describe the mineralogical and chemical change involved from the early shear zone nucleation stage to the widening stage. These changes, as well as the P-T conditions of the deformation, will be modeled using phase equilibria modeling (pseudosections). All these results and observations will be used to determine how chemical and mechanical processes interact during the formation of a shear zone.
7) Crystallographic preferred
orientations and CPO-derived physical properties of rocks
The aim of this lecture is to present information about the development of crystallographic preferred orientation (CPOs) in geological materials, with examples, in quartz and calcite. The following topics will be addressed:
(a) Mechanisms of formation of crystallographic preferred orientation in Earth's materials
(b) CPO examples of quartz in nature and experiments
(c) CPO examples of calcite in nature and experiments
o The field area is easy of access
and no climbing or special Alpine experience is required. However, the field course
is in a high mountain environment and adequate equipment is essential. What do you
need? Download the checklist!
o Course language: English.
o Course participants: priority is given to PhD students, post-Docs and young researchers specializing in structural geology. Finishing masters students in the process of starting PhD will be considered if there are places left.
o Course max number of participants: 35 (on a first come first served basis).
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