Saturday, August 9, 2014

Geology



Geology was one of those subjects that failed to grab my attention as a youngster. Not that many subjects did. In college, they tried to hide it under the rubric of Earth Science but nobody was fooled. Same old boring rocks with unpronounceable names and worse yet, eons of dates to remember. Now sixty years mature and cruising in geographically interesting regions, I am finally attentive to my rocky surroundings.

There is nothing like being anchored in a secluded cove surrounded by the signs of obvious terrestrial upheaval etched in the rocks, even if it occurred a billion years ago, to start me wondering about what caused it. As Carrie Rose, our 32’ Nordic Tug, has cruised from Chicago south to north, west to east and now north to south she has traversed a flattened landscape the result of recent glaciers, then through one to two billion year old rock in Canada and New York, interspersed with 150 million year old sedimentary rock, and now sits in a marina which was once a slate quarry that dates to 450 million years ago.

I am not sure why the rocks have called out to me. Maybe it is because of the leisurely pace we cruise by them: 6 to 10 mph as opposed to 60 to 70 mph. Maybe because on the boat we live among them. It is easy to tell when we passed from the hard dustless environment of the granite of the Canadian Shield to the muddy rubble of the friable rock laid down layer by layer in an ancient river bottom.

Now we are mingling with rock midway between the two above extremes. It is layered in many places but much less prone to disintegrating into dust and mud. It crushes under foot like a hard cracker. And here and there, there are intrusions of smooth or volcanic rock that slid over the top or penetrated from deep below. Here on the Lake Champlain islands we can see how the rock bent and twisted in respond to the stress placed on it.

The owner of the marina informed me that the lake’s bottom around these parts is tricky to anchor on. That I will think the anchor has a good hold on the bottom but if the wind picks up it may not. It seems the mud and weed that the anchor grabs onto is only a shallow layer resting on smooth shale. The moral of the story is to anchor in a bay protected from the wind, and if the wind picks up or changes direction keep a close watch on the anchor. This I promised to do.

Soon we will leave Carrie Rose in Vermont for the winter and before venturing home spend a few days amongst the granite outcrops in NYC’s Central Park, and amid the canyons of buildings constructed of sand and limestone, and marble and granite brought in from as close as Vermont and as far a Carrera and beyond. The rock walls and floors in NYC have been selected, polished, and laid before me. It is like geology on the hoof and it cannot help but grab my attention.



A Coral Reef in the Rocks