A hardy group of structural geology students, equipped with hard hats,
safety glasses and rock hammers, descended on the Pike Industries sand
and gravel quarry in Hookset, NH. I'm not sure I'd want to meet this
group on a dark street. The fellow with the white hard hat is Ryan
Crosbie, our intrepid quarry guide.
quarry is sited in the Rangley formation, a wonderful mix of igneous
and metamorphic rocks and plenty of yummy structural geology. Can you
spot the boudins in the image below?
make things even better, the Pine Hill fault runs through the quarry.
Careful investigation by the students determined that the damage zone
was at least 100 m wide which suggests that this is a major fault.
Isolated surface outcrops indicate a length of at least 50 km.
crushed stone for aggregate and asphalt are produced at the quarry. We
also learned about the quarrying operation and the associated
environmental issues. Many thanks to Ryan Crosbie who was an informative
and helpful guide to the interesting geology of the quarry and the