Thursday, July 11, 2013

Part 133 - Marble Mountain

It took about thirty minutes of slow driving to arrive at the top of Etna Summit.  I was grateful that the driver went slowly because it was a winding road with blind turns.  At the summit, the hikers settled up with the driver, thanked him for his help, and then pulled their packs out of the back of the truck.  There were eight of us; the fast hikers took off first, the slower ones next, and I fell in at the back of the pack.  No sense in trying to get ahead of the pack, as I knew everyone would eventually pass me.

The trail climbed to the crest of the mountain and stayed there all day, giving excellent views down into deep-glaciated Mill Creek canyon and North Russian canyon before cresting Razor Ridge.  En route, I passed a couple of small lakes – Fisher and Martin, and camped for the evening in the vicinity of Cliff Lake.  Although I couldn’t see it from my camping site, I knew that off to my left, down the slope a ways was the lake with the strange name of Man Eaten Lake, and the location of a possible Big Foot sighting in 1998.  Mileage today was only fifteen miles; not much, but at least it got me away from the trail town of Etna.

 On the trail early again this morning; the trail stayed high on the crests of the mountain, traversing from one glaciated canyon to another, and entered the heartland of Marble Mountain Wilderness.  From the distance, I could see the crown jewels of this wilderness area – Marble Mountain, Black Mountain, and Kings Castle.  The trail made a steep descent into Little Marble Valley, which lay at the base of Marble Mountain, two thousand feet of vertical rock that shot straight up from the valley floor.

 Just before entering the valley, there was a junction with the Marble Rim Trail that allowed a hiker to climb to the top of Marble Mountain for unprecedented views of the Klamath Mountains.
Of great interest to me were the marble formations for which Marble Mountain Wilderness was named.  I had never seen a geological formation comprised of marble, as my whole life’s experience with geological formations had been limited to the sandstone, limestone, and shale formations found along the Colorado River in Utah and the granite formations along the Main Salmon River corridor in Idaho.

From my geology studies, I remembered that marble starts out as limestone, and limestone is a sedentary rock formed in warm, shallow seas from organic sediments comprised of shell, coral, algal and fecal material; additionally, limestone can also form from calcium carbonate that precipitates out of the water and settles to the bottom of the seabed, and collectively is known as the mineral calcite.  Calcite has great cementing properties, thus, the gray sludge or mud that collects and coagulates on the bottom of the ocean floor over time becomes solidified.

Limestone is hard, as hard as the concrete in the foundation of a building or the sidewalks in front of your home, and is quite impervious to erosion.  When it’s exposed at the surface of the earth, often the fossil remains of crinoids – think starfish or sea urchins; ammonites - think nautilus and trilobites, can be found in the matrix of the rock.  When John Wesley Powell first explored the Colorado River through the Grand Canyon, he quickly discovered that when limestone formations appeared at the water’s edge, he could expect nasty rapids, as blocks of limestone that end up in the river don’t erode very fast compared to sandstone, which melts like a cube of sugar.

Limestone, when subjected to great heat and pressure, alters its physical form and structure to create a new substance called marble.  Basically, the mineral calcite found in limestone forms small crystals that change the texture of the rock.  All the fossil remains of organic material are obliterated in the process, thus no fossil fragments are ever found in marble. On a scale of one to ten on the Mohs scale of hardness, marble has a ranking of three, which means it’s pretty soft.  Marble is highly desirable as a medium for carving statues, and if you examine a marble statue up close, you will observe that it has a wax-like sheen to it.  The reason - marble is easy to polish.

When I arrived at the base of Marble Mountain, out of curiosity, I checked several samples for fossil remains, and of course, I found none.  Then, using my small knife, I scratch the rock to test for hardness; it is soft, which made me wonder why this mountain of marble hadn’t eroded away faster than the surrounding slabs of granite.

Parts of the trail were exceptionally rocky today; in fact, it traversed along what are known as active scree slopes, which meant the loose rocks are continually sliding down the mountain, and if maintenance crews didn’t stay on top of the problem, the trail, from one year to the next, may not be there.   

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