Ontario Cave Reveals Some Really Unusual Geology

IMG_5170, originally uploaded by Mic2006.

A friend and I had visited a small local cave today to enjoy its beauty and hopefully examine the area and locate other likely caving spots. Following up a densely wooded valley there were signs of slumping rock and an old stone construction along the valley wall. We soon abandoned this course of action as it was not as fufilling as photography in the cave. It is such an incredible spot that the explorations away from the cave become harder to justify as your distance from the tunnels increases.

Having visited here on several previous occasions I had always regretted not paying better attention to the rock and was excited to find the diverse and beautiful metamorphic striations through which we were exploring. It is a change to the typically sedimentary nature of Ontario’s cave strata.

Near the upper entrance to the cave (or natural land bridge as it is also known) the rock dipped at a steep angle down into the ground and a little stream had cut a notch into the near vertical strata. Bending down beneath an overhanging slab I observed a salmon-colored plate of syenite – a silica poor rock, its surface peppered with brassy prisms of corundum. Deeper down the passage the marble strata was worn into all sorts of incredible grooves and flakes of mica and small crystals of indeterminate system stood out in bas-relief from the surrounding rock. I had hoped that they might also be a finer grade of corundum as some crystals almost appeared spindle-like in form and of a milky color. Pink blocks of calcite were exposed higher on the walls.