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Unformatted text preview: High ellipticity values are high less
than 400 m from a fault, whereas low values to undeformed molds are found more than 1000 m from a fault. These 427 observations indicate that greater strain occurs closer to faults, and therefore is not a strain pervasive to the entire
Shattered pebbles and veins
The conglomeratic unit atop of the Cretaceous sequence of the Piedras-Girardot foldbelt shows a conspicuous
deformation fabric of intragranular calcite-filled microscopic veins perpendicular to bedding. The total area change
accommodated by intraclastic veins with average intensity is only between 1 and 2 percent. The trends of these
microscopic veins is mostly to the northwest, defining a direction of the maximum finite stretch of the finite strain
ellipse to the northeast. Such stretch is approximately perpendicular to the direction of minimum finite stretch
independently deduced from cleavage and deformed fossils.
The results above outlined, combined with a palinspastic reconstruction of the Piedras-Girardot foldbelt (Fig. 2...
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This document was uploaded on 02/06/2014.
- Winter '14