(1) Závada, P., Schulmann, K., Racek, M., Hasalová, P., Jeřábek, P., Weinberg, R.F., Štípská, P., and Roberts, A., 2017, Role of strain localization and melt flow on exhumation of deeply subducted continental crust: Lithosphere, https://doi.org/10.1130/L666.1. GSA Data Repository Item 2017403 Data Repository File (Role of strain localization and melt flow on exhumation of deeply subducted continental crust) This data repository file presents the additional information about the methodology and provides extra datasets associated with the manuscript. The first section, the “Image analysis of melt topology”, explains in detail the image analysis procedure (segmentation) of the cathodoluminescence image mosaics (Fig. DR1). The second section, “Thermodynamic modeling of PT equilibria”, includes the details of the phase equilibria modeling for the pressure and temperature estimations. “Additional datasets” shows seven phase maps and details of the microstructures in hand line-drawings alongside the cathodoluminescence images that are also presented as a shorter version in the Fig.8 of the manuscript (Fig. DR2A-G and DR3A-G). Another panel (Fig. DR4) reveals the pseudosection calculated using the thermodynamic equilibria modeling. In addition, the isocon and volume-composition diagrams show the comparison of the element contents between the studied anatectic samples and are presented in Fig. DR5. Compositional data for representative mineral paragenesis that were obtained by electron microanalysis and used later for the P-T calculations (P-T pseudosection in Fig. DR3), are presented in Table DR1. Whole rock compositional data of the studied samples are shown in Table DR2. Volume-composition calculations displayed in Fig. DR5, are also shown in Table DR3. Image analysis of melt topology Image analysis processing was performed in order to discern the contrasting phases in the cathodoluminescence images (CITL Mk5-2) interpreted as new phases that crystallized from interstitial melt (e.g. Hollness and Sawyer, 2008; Hasalová et al., 2008b; 2011). The segmentation worked well for albitic overgrowths on plagioclase grains (e.g. in plagioclase bands, K-feldspar bands or inclusions in quartz) that have contrasting dark purple or dark blue
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(1)
Závada, P., Schulmann, K., Racek, M., Hasalová, P., Jeřábek, P., Weinberg, R.F.,
Štípská, P., and Roberts, A., 2017, Role of strain localization and melt flow on
exhumation of deeply subducted continental crust: Lithosphere,
https://doi.org/10.1130/L666.1.
GSA Data Repository Item 2017403
Data Repository File (Role of strain localization and melt flow on exhumation of deeply
subducted continental crust)
This data repository file presents the additional information about the methodology
and provides extra datasets associated with the manuscript. The first section, the “Image
analysis of melt topology”, explains in detail the image analysis procedure (segmentation) of
the cathodoluminescence image mosaics (Fig. DR1). The second section, “Thermodynamic
modeling of PT equilibria”, includes the details of the phase equilibria modeling for the
pressure and temperature estimations.
“Additional datasets” shows seven phase maps and details of the microstructures in
hand line-drawings alongside the cathodoluminescence images that are also presented as a
shorter version in the Fig.8 of the manuscript (Fig. DR2A-G and DR3A-G). Another panel
(Fig. DR4) reveals the pseudosection calculated using the thermodynamic equilibria
modeling. In addition, the isocon and volume-composition diagrams show the comparison of
the element contents between the studied anatectic samples and are presented in Fig. DR5.
Compositional data for representative mineral paragenesis that were obtained by electron
microanalysis and used later for the P-T calculations (P-T pseudosection in Fig. DR3), are
presented in Table DR1. Whole rock compositional data of the studied samples are shown in
Table DR2. Volume-composition calculations displayed in Fig. DR5, are also shown in Table
DR3.
Image analysis of melt topology
Image analysis processing was performed in order to discern the contrasting phases in
the cathodoluminescence images (CITL Mk5-2) interpreted as new phases that crystallized
from interstitial melt (e.g. Hollness and Sawyer, 2008; Hasalová et al., 2008b; 2011). The
segmentation worked well for albitic overgrowths on plagioclase grains (e.g. in plagioclase
bands, K-feldspar bands or inclusions in quartz) that have contrasting dark purple or dark blue
(2)
colors with respect to pinkish plagioclase and light blue K-feldspar in the optical
cathodoluminescence images (Fig. DR1). Post-processing including manual correction of the
automatically segmented images to obtain best estimate of the modal content of individual
ized in the interstices.
In the first step, a set of cathodoluminescence images (~90-150 pcs) were stitched
together using a software “kolor auto pano GIGA” (www.kolor.com) that included automatic
blending of the sutures between the stitched images and exposure correction. Resulting
images were then subjected to image segmentation in ArcView 10.2.1 using the “Maximum
likelihood classification” method for selected color samples. Resulting classified image was
corrected by smoothing procedure (‘Boundary clean’ function in Spatial Analyst toolbox) and
transformed to a shapefile (‘Raster to Polygon’ conversion tool). Finally, resulting shapefiles
were corrected with ‘Eliminate’ tool to merge small polygons with larger ones to decrease
size of the shapefiles (typically exceeding 100 000 polygons after raster to polygon
conversion). Manual correction by merging and splitting of the individual polygons was
applied in the last step. Melt content and modal analysis from fine-grained samples (EC12-8G
– mylonite; EC12-8C2, EC12-K6 – granofelses), was carried out by manual tracing of
representative areas (at least 500 grains), since automatic segmentation method did not
correctly identify the small melt pockets. Migmatite sample EC12-3C2 was also interpreted
only by manual tracing of pseudomorphed melt pools. Shape preferred orientation of the melt
pockets was obtained by line tracing (2 node lines) of ‘melt films’ primarily in the K-feldspar
aggregates. Shapefiles (line) were then statistically analyzed in Matlab™ using the PolyLX
Matlab™ toolbox (function „prose“) (Lexa et al., 2005).
Thermodynamic modeling of PT equilibria
In order to get constraints on the P-T conditions of coupled deformation and melt flux,
the P-T pseudosection was calculated for the representative sample of the banded orthogneiss
(sample EC12-K1), the results of the modelling were then compared with the observed
mineral assemblage and corresponding mineral chemistry, namely of muscovite and garnet
(see Table DR1 for representative analyses). The P-T pseudosection was calculated using the
software Perple_X (Connolly, 2005, version Perple_X 07) with dataset 5.5 (Holland &
Powell, 1998, November 2003 upgrade), in the system MnO–Na2O–CaO–K2O–FeO–MgO–
Al2O3–SiO2–H2O–TiO2 (MnNCKFMASHT). The following activity models were used: Mn-
bearing model for cordierite is a combination of formulations by Mahar et al. (1997) and
Holland & Powell (1998), garnet is from White et al. (2007), biotite from White et al. (2005),