After we explored the Ogre’s Den and the Miner’s Cave we headed on over to what is called the Marcus Landslide, one of the largest landslides in Arizona when tons of rocks just slid off the hillside above us (oh, my) onto the desert below. Enough material to fill 6 football stadiums. Here’s a picture from the side in the late afternoon sun as Gary and I approached it along the trail. I am looking away from the slide and all the slide material is on the right. Note how many boulders are on the desert floor here to the right but none to the left. Hmmm.
Let’s go through some of the facts about the landslide. Here are some of the massive boulders that came down.
The rock to the left is the ‘Submarine’ rock and the one to the right is the ‘Torpedo.’ Those who found discovered that this was a huge rock slide and studied it got to name the rocks. BTW - I’m in the picture too.
I liked these two rocks.
How did 25.8 billion pounds of massive boulders along with soil, smaller rocks and vegetation all slide down the slope and across the valley below for 1 mile in a minute at approximately 44 mph?
Here’s the previous angle of the slope. Note how steep it is - probably that is one of the main causes: massive boulders, steep slope, lots of rain.
They slid so well on what is called gnus - small ball-bearing-like bits of ground up granite. We hike on these little ‘marbles’ every time we come to this area of Phoenix to hike. These little pea-sized bits of rock are slippery and one reason why the boulders slid so far.
Here’s what it all looks like now.
So, that’s my version of the geology of the landslide. However, the story of its founding is pretty cute. Seems that two young geologists were with a group of older professorial types who got involved in a lengthy, involved discussion of something. The two young guys wandered off, bored to tears probably, and sat down on some boulders for lunch. They noticed some differences in the rocks above them and then looked at all the rocks piled at their feet. Same rocks. Wow, how did so many of these rocks get here and why are they all pointing back up the hill? Hmmm, they mused. And they exchanged ideas and, voila, they realized that an ancient landslide had occurred.
Today, not only is it a great place to hike and learn, a great place for geologists to study ancient land movement BUT a real caution:
DO NOT BUILD HOMES NEXT TO STEEP SLOPES WITH LOTS OF MASSIVE BOULDERS ON THEM. Let’s build a hiking trail.
As we hiked the last 2 miles back to our car, we met up with a large family with 4 generations. They asked if we could take their picture and we walked back to our car with them. The young son was quite a talker. We learned the subjects he gets in 2nd grade and how a typical day goes. Then we played ’50 Capitals’ where we would name a state and he would tell us the capital of that state. Boy, did I louse up - I thought the capital of Maryland was Baltimore. Nope, he told me, it is Annapolis.
We got back to the trail head and said good-bye to our new friends and headed on over to the bathrooms. Not only did I learn the capital of Maryland today, I also learned a lesson I have learned many times over but sometimes forget: check the toilet paper BEFORE you sit down. Oh, darn. Luckily, I had some Kleenex in my pocket. Saved.
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