Polished stone: breccia texture
Scale: each of the larger, elongate black fragments are about 2 cm wide.
As noted for previously posted shots of this same breccia (see captions for breccia photos in my "Geology in building stone" album), this is a tectonic breccia, produced via fault motion and hydrofracture veining. Larger fragments/clasts can be seen being disaggregated into smaller fragments ('caught in the act,' we might say), with some small clusters of fragments showing jigsaw-like patterns where the pieces (smaller fragments) can be fitted back together. Note the numerous examples of small whitish veinlets cutting across and breaking apart the larger dark fragments.
C. J.R. Devaney
Polished stone: breccia texture
Scale: each of the larger, elongate black fragments are about 2 cm wide.
As noted for previously posted shots of this same breccia (see captions for breccia photos in my "Geology in building stone" album), this is a tectonic breccia, produced via fault motion and hydrofracture veining. Larger fragments/clasts can be seen being disaggregated into smaller fragments ('caught in the act,' we might say), with some small clusters of fragments showing jigsaw-like patterns where the pieces (smaller fragments) can be fitted back together. Note the numerous examples of small whitish veinlets cutting across and breaking apart the larger dark fragments.
C. J.R. Devaney