Laboratori de Deformació Experimental (Universitat Autònoma de
Barcelona, Spain)
The BCN-Stage at the Departament de Geologia, Universitat Autònoma de
Barcelona (Carreras et al., 2000) is a kinematically controlled device
that operates under pure shear boundary conditions at variable room
temperature (range of ≈20-35ºC). It is ideal for the modeling of ductile
and ductile-brittle structures with analogue materials such as paraffin,
plasticine, polymers or even other materials with melting point at room
temperature such as chocolate, to simulate cooling of melts during
progressive deformation (Druguet and Carreras, 2006). The apparatus is
fully capable of reproducing the conditions that lead to deformation
partitioning. Several analogue materials can be combined in a single
experiment in order to set complex initial configurations which may
include layer and mechanical anisotropies, bodies of different shapes
made up of rigid or molten materials, and material discontinuities
(Druguet et al., 2015).
It is a prototype designed from a concept of J. Carreras and M. Julivert
implemented by the company Enginyeria Teknics Sabadell, S.I. The sample
is inserted in a rectangular deformation cell. While the vertical (Y)
dimension of the cell remains constant at 10 cm, the lengths of the X
and Z sides are variable, being driven by two electric motors which
shorten/extend the deformation cell. In order to maintain confinement
conditions and allow visualization during the experiment, the sample
inside the deformation cell is covered by a thick glass panel. The
deformation is operated by computer using the "Makina Control" software
designed by AdCon sistemes S.L. Accessory devices connected directly to
the BCN-Stage are a high resolution digital camera, two spotlights and a
heater that is operated by a temperature control.
The mechanics and software of the BCN-Stage have been recently updated
and a high-resolution digital camera has been adapted to the apparatus
for photographic monitoring of experimental models. It is considered as
one of the most sophisticated deformation devices in the world.
The BCN-Stage experiments focus on the assessment of the factors
controlling localization and distribution of deformation in the Earth’s
crust, preferably under ductile and ductile-brittle conditions. Folding
and boudinage structures, fault and shear zones, and structures
associated with the presence of rigid or soft inclusions are on the
scope of our experiments. The controlling factors can be grouped into:
rheological contrasts (e.g. lithological variations), mechanical
anisotropies (e.g. foliation), structural discontinuities (e.g.
fractures) and the interaction between different lithomechanical
parameters. The impact of particularly complex pre-existing
configurations on the distribution of the deformation can also be
analyzed. The main parameters to be evaluated are the medium
(homogeneous / heterogeneous, isotropic / anisotropic) and, in the case
of heterogeneous and anisotropic media, the orientation of the
anisotropy (bands, foliation, fractures) with respect to the kinematic
axes.
Please find further information:
http://grupsderecerca.uab.cat/miet/content/laboratory
