Breccia and pebble columns associated with epigenetic ore deposits

The author defends various statements made in his paper on breccia and pebble columns [Geoscience Abstracts 3-3111]. He points out that "co-hydrothermal structures differ from pre-hydrothermal volcanic structures in showing closer spatial coincidence with mineralization, lack of fused matrix, and in some cases show no evidence of having been volcanic." The absence of metallization associated with the pipes does not indicate a lack of hydrothermal activity. In addition, this lack of metallization need not point to a volcanic origin. Finally, mineralization stoping as a mechanism for breccia pipe formation need not be dismissed simply due to a lack of evidence for physical connection with the surface at the time of ore deposition.

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