November 18, 2008

Hog Back Heaven

Last week I had a warm window of opportunity to get out and hike up to the hogback adjacent to the “Ecology Park” here in Canon City. The wind was blowing pretty strong, especially at the top of the hogback, which made it quite cold compared to the parking area where I started from, but it was worth it. First, a little history about the hogback and my interest in it.

There are rare places on land where one gets to see the physical evidence of colossal collisions of time and space. Here in Canon City we sit on the edge of an ancient sea dating back some 65 million years ago(MYA). But older still are the mountains that cradle us. Along the northern, and especially western edge of town a prominent hill circles around us and marks the dividing line between sea and mountains, and between the Precambrian and Cenozoic eras. The difference is about a half a billion years, if you can really imagine a time such as that. Even though the sea dried up many millions of years ago, its beginning and end were only a yesterday compared to the distant past when the rocks that make up the mountains were formed. The hill that surrounds the city here is known as the “Hogback” and is made up of rocks of the Dakota Sandstone formation. Skyline Drive, along the cities western edge, traces along this hogback. The portion that I climbed lies just to the south of Skyline Drive across Highway 50 and the Arkansas River.

Older still, by about 500 MYA, are the granite, and metamorphic rocks that surround the Royal Gorge. The Arkansas River cut down to and exposed the precambrian granites, mostly of the Pikes Peak granitic pluton, but just above them are the metamorphic and sedimentary rocks of the Ordovician Period. Laced throughout these rock layers are magmatic intrusions and pegmatites. Many different kinds of crystals can be found in these pegmatites and the interfaces between them and the surrounding rocks. The granites at the bottom are actually older still at about 1,700 MYA and are considered to be remnants of the ancestral Rockies. Because of the heat and pressure presented by the uplifting of these older rocks next to the more recent sea rock(the Dakota Sandstones of the Hogback) many minerals and crystals can be found in this area. For me, the most curious deposits are the gemstones and our friend Uranium!

I climbed up the “top” and geologically newest side of the Hogback to look across Grape Creek over the mountains that surround the Royal Gorge. the first half consists of mostly loose gravel and debris that slid down and accumulated along the bottom. A farmer over a century ago created a little road that climbed along the lower half of the hogback. I followed this as far as I could and then headed straight up the solid rock face on this eastern side. Some of the pictures I took show the ripples of an ancient beach frozen in rock and time. Once I reached the ridge line near a little notch I could look over to see the much older mountain side. From this notch I could look down on the western edge of the hogback and see the remains of an old mine, the creek, and further still the pink granite at the base of the mountains. I was at this point sitting on the edge of time and space quite literally.

View more pictures of my hike here.

1 comment:

Shaw said...

Hey jody! Hogback looks quite beautiful. Did the area see any change in colors with the trees for fall? Not sure if fall in the higher elevations is quite the same?

I had 25 folks for SFN/Psychonomics this year. That's alot for this group. All went well though, just busy. I spent the past couple of days vegging out, shopping and drawing. I feel back to normal now! I have no travel plans till Xmas, heading home.