I Discover a 1935 U.S. Coast and Geodetic Survey Benchmark

I Discover a 1935 U.S. Coast and Geodetic Survey Benchmark

Geology, Technology
I travel the county quite a bit, meeting and talking with people. Since my conversation is varied, I naturally receive all kinds of responses. One day, a man who is a bit of a recluse drew my attention to an artifact at the edge of the property. He told me that if anyone was to dig it up, including himself, he would get into trouble with the Federal Government! Naturally, I was intrigued. What was this artifact? The Unobtrusive Artifact The man pointed to a small concrete-filled pipe, rusted on the outside, that stuck up from the ground only a very little distance. In the middle of the smoothed concrete top was a little disk, imprinted with words in a circular fashion, much like a large coin. The words read:…
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Why All Helium Has Not Escaped Earth’s Atmosphere

Geology, Physics
[caption id="attachment_14665" align="alignleft" width="440"] Hydrogen or Helium?[/caption] Ninety of the elements occur in nature. The smallest and lightest of the elements is hydrogen. Yet, it is abundant in Earth. Almost no hydrogen gas escapes Earth’s atmosphere. This is partly because hydrogen is reactive and exists almost exclusively in combination with other, heavier elements. Helium, too, is a gas. It is the second lightest element. However, it is neither reactive nor abundant. It does not occur in nature in compound form. Why doesn’t it all escape Earth’s atmosphere? Comparing Hydrogen and Helium Although hydrogen is the lightest element and atom, it almost never exists, even as a gas, in atomic form. It assumes, not monatomic form, H, but diatomic form, H₂. The weight of that is twice the weight of an…
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Devils Dice – What Are They?

Chemistry, Geology
[caption id="attachment_13950" align="alignleft" width="380"] Peruvian Striated Pyrite - Rob Lavinsky iRocks.com CCSA3.0[/caption] I was in my 30s when I first heard of Devils Dice. What are they? I was raised in New Jersey. At the age of 33, I moved to Virginia. This short north-to-south emigration exposed me to certain speech, food, and culture changes. It took me a month to get over the accent. During that time, my brain adjusted and the accent sounded totally normal to me! I missed scrapple a lot. Since then, I’m happy to say scrapple successfully has invaded the south. But there were other changes as well. In the south, there are buzzards. There are red bud trees. There are ABC stores! Even the ground itself offered something new. There is this kind of…
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Why is Soapstone Slippery?

Geology
[caption id="attachment_8570" align="alignleft" width="380"] A 12th century soapstone Byzantine relief.[/caption] Most rocks are rough to the touch. Some are smooth. Asbestos is stringy. Sulfur is brittle. One very interesting rock variety is soapstone. It is called smooth and slippery. What makes soapstone slippery? I was raised in the North then moved to the South to where soapstone is is mined, Nelson County, Virginia. I take special interest in the stuff. As a young child, I watched spellbound as my father took a handheld soapstone and used it to sharpen our enormous carving knife. General Rock Types As kids we were taught there are three types of rock, sedimentary, igneous, and metamorphic rock. Sedimentary rock forms from mineral and organic materials near at earth's surface. These deposits form rock deposits over…
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What is Red Clay?

Geology
[caption id="attachment_4995" align="alignleft" width="440"] Red Clay - CCA 2.0 Generic by CC:BY[/caption] Red clay or red mud, is the common name for a variety of ultisol found in the SE United States. Residents who live in the area often speak poorly of the soil, although in fact it isn't as poor as all that. Some dislike it because it is hard to keep their clothes and homes clean. The USDA’s “Soil Taxonomy – 2nd Edition” includes ultisols among its twelve soil orders. Red clay is rich in weathered minerals. Over time, rain leaches out soil calcium, magnesium and potassium. This makes a soil 'old.' Particles in such soils are smaller than 2.0 microns. The red color is due to iron oxide. General Clay Composition Clays include the kaolinite of red…
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Wissahickon Creek Garnets

Geology
[caption id="attachment_4022" align="alignleft" width="440"] Wissahickon Creek[/caption] Childhood memories are intense. They can last into adulthood. One memory I haveconcerns a trip to see my grandparents. They lived in Manayunk, PA. I lived in Camden County, NJ. Toward the end of the trip, we would pass the Wissahickon Creek. The area of the Wissahickon is beautiful, both for its natural scenery and its architecture. Especially so for the Henry Street Bridge. I was about ten years old at the time, in 1958. I had a deep interest in rock hounding, so I would gaze admiringly at the Wissahickon Creek. Just the same, we never did stop there. What was it that fascinated me so? The Wissahickon's garnet schist. [caption id="attachment_4024" align="alignright" width="405"] Henry Avenue Bridge crosses the Wissahickon[/caption] Wissahickon Creek Garnet…
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