The Gold Report: Merrill, speaking as a geologist, what makes the Guerrero Gold Belt in Mexico so highly prospective for gold and silver mineralization?
Merrill McHenry: Two words: plate tectonics. Two tectonic events in that area of sufficient scale to create an entire region filled with gold mineralization.
In more detailed terms, the Chortis plate, which was about the size of Colorado, impacted the western side of southern Mexico. The first event, about 140 million years ago, created "laramide" north-south extensional faults. That was followed, about 70 million years later, by a strike-slip to the southeast. As the strike-slip slipped and subducted under the southern portionwhat is today Guerrero Stateit rotated many of those north-south transitional faults and shear zones into roughly 40-degree and other angles, creating a chimney effect, which brought the mineralization, in liquid form, much closer to the surface. In geological terms, this is called a metasomatic transfer. The strike-slip also created various low-angle extensional faulting allowing laterally displaced mineralization and improving strike-length potential. Continue reading "Geologist Merrill McHenry Keeps His Eye on the Guerrero Gold Belt"