A land formation, less extensive than a plateau, having steep walls and a relatively flat top and common in arid and semiarid parts of the southwestern U.S. and Mexico.
Mesas are geological landforms characterized by flat-topped, steep-sided hills or mountains. They typically have a small, relatively flat summit area that stands above the surrounding terrain, often in the form of a plateau. Mesas are commonly found in arid or semi-arid regions and are a result of various geological processes. Mesas are formed through a combination of erosion and uplift.
I was driving through Carroll County, Georgia the other day and saw this sign. On previous trips, a multitude of houses was displaying “No Rock Quarry” signs. I have finally decided to see just what is going on in this county.
Luminescent paint is paint that exhibits luminescence. In other words, it gives off visible light through fluorescence, phosphorescence, or radioluminescence. There are three types of luminous paints: fluorescent paint, phosphorescent paint and radioluminescent paint.
When a radium salt is mixed with a paste of zinc sulfide, the alpha radiation causes the zinc sulfide to glow, yielding a self-luminescent paint for watches, clocks, and instrument dials. From about 1913 up until the 1970s, several million radium dials, coated with a mixture of radium-226 and zinc sulfide, were manufactured.
I was watching the television series “The Mystery at Blind Frog Ranch”, season 2 episode 5 on Discovery, when they came across some rocks that had been drilled and gallium placed in the voids. The rocks were then crated and hidden in a cave system. I wanted to research the gallium for myself.
These formations may also be exposed in caves, stream valleys, sinks, and in coastal lowlands.
Limestone, shell, and dolomite are types of marine deposits that have accumulated in Florida over millions of years during times when the state was covered over with seawater or shallow marshes. During this time, limestones formed by chemical deposition and the accumulation of shells from sea creatures. Many invertebrate animals (animals without backbones) take calcite from seawater to construct their shells. When they die, the shells fall to the sea bed. Over the millennia, their remains slowly built up layers of sediment thousands of feet thick. These sediments are the limestone, shell, and dolomite formations that are mined today.