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Does this photo show evidence of ductile or brittle deformation? (Field of view is about 15 cm wide and 10 cm tall)

a) Mainly ductile
b) Mainly brittle
c) Equal evidence of ductile and brittle deformation
d) Unable to determine deformation type from the photo

1 Answer

3 votes

Final answer:

Without a photo, we cannot discern whether the evidence points to ductile or brittle deformation. Ductile deformation is associated with bending and folding under high pressure and temperature, while brittle deformation involves breaking and fracturing of rocks under lower conditions.

Step-by-step explanation:

Without a photo, it's not possible to determine whether the deformation is ductile or brittle. Ductile deformation typically involves bending and folding of rocks, often under high pressure and temperature conditions that allow the rocks to deform plastically. In contrast, brittle deformation involves the fracturing and breaking of rocks, which occurs at lower pressures and temperatures where rocks are unable to undergo significant plastic deformation.

In a geological context, folds are evidence of ductile deformation (as with layer G showing compression and folding), while faults are indicative of brittle deformation. To identify the rock types such as sedimentary, igneous, or metamorphic, one should look for texture, layering, and mineral composition that respectively define each rock type. Concerning strain, a graph showing stress vs. strain can help determine whether rocks have undergone brittle or ductile deformation, as the pattern of the curve changes at the point of failure or permanent deformation.