The Proterozoic Era
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About
300 to 500 million years ago, slates were layers of black mud on
the bottom of shallow seas. As epochs passed, the mud hardened by
the process of compaction and cementation. At the same time the
sea basins sank, allowing vast amount of new sediments to settle
upon the hardening mud.
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After
some 2 to 400,000,000 years the slates-to-be were firm shales that
lay beneath younger formations 5 to 6 miles thick.
As the Paleozoic Era came to an end, the continents were squeezed by rocks beneath the oceans. They pushed the hardened sea muds upwards, shoving and crumpling them into huge, high folds. |
Creating Mountains
| When the shales were squeezed into sharp folds, pressure became so great that they raised nearly 6 miles of rock above them crumpling the top-most shale into mountains. The intense heat and pressure generated caused many particles to recrystallize and flatten, | often at right angles to direction of compression. This gave the rock a "grain" called "slate cleavage" that allows it to be split easily along one plane but not another. |
Components of Slate
| Slate is chiefly comprised of quartz and illite, with mica, calcite, and minor quantities of other various minerals. Slates vary in color, most commonly seen in black, gray, red, purple, or green. | The red color is due to the presence of Hematite, while green colors are due to Chlorite. Grey and black are due to carbon and/or graphite. Shades of red, purple and tan are related to varying amounts of iron oxides. |
Quality Slate from ASC
| American Slate Company has the largest inventory and range of natural colors of the finest domestic and international slates and quartzites and the largest selection of natural slate roofing and floor tiles in a range of over sixty natural colors from around the world. | Roofing slate is available in standard and rough texture in a wide range of colors. Flooring slate is available in a variety of sizes 12" x 12" to 24" x 24" plus irregular random to 4 ft. The variety of material, plus the ability to machine to an even thickness, will fit almost any project requirements. |
| The natural beauty of slate enhances the quality, image, value and safe usage in residential and commercial projects and is an excellent product for both indoor/outdoor living styles. | You are invited to visit one of our showrooms to see the quality of our products, along with the broad range of colors, sizes and textures. We would also be pleased to to meet with you and to provide samples or discuss uses of slate in your projects, without obligation. |
Welcome
to the natural and enduring beauty of slate!
