Search results
Results from the WOW.Com Content Network
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, [1] [2] categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start fires. Flint occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones.
Lynch Quarry Site, North Dakota, NRHP-listed and a U.S. National Historic Landmark, a flint quarry that was "a major source of flint found at archaeological sites across North America, and it has been estimated that the material was mined there from 11,000 B.C. to A.D. 1600."
Alibates Flint Quarries National Monument is a U.S. national monument in the state of Texas. For thousands of years, people came to the red bluffs above the Canadian River for flint, vital to their existence. Demand for the high-quality, rainbow-hued flint is reflected in the distribution of Alibates flint through the Great Plains and beyond.
Flint mining is the process of extracting flint from underground. Flint mines can be as simple as a pit on the surface or an area of quarrying, or it may refer to a series of shafts and tunnels used to extract flint. Flint has been mined since the Palaeolithic, but was most common during the Neolithic.
Concretions in Torysh, Western Kazakhstan Concretions with lens shape from island in Vltava river, Prague, Czech Republic Marlstone aggregate concretion, Sault Ste. Marie, Michigan, United States A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary ...
The Hill/Decision Desk HQ’s aggregate of polls shows Harris and her GOP opponent, former President Trump, neck and neck in Michigan. The vice president holds a razor-thin lead with 48.3 percent ...
The Lynch site, whose known extent is at least 690 acres (280 ha) has an estimated 20,000 pits from which flint was quarried. The pits range in depth from 3 to 10 feet (0.91 to 3.05 m), and are accompanied by spoil piles. It is located on the banks Spring Creek, a tributary of the Knife River. [8]
Among the sedimentary rocks, chert and flint are cryptocrystalline. Carbonado, a form of diamond, is also cryptocrystalline. Volcanic rocks, especially of the felsic type such as felsites and rhyolites, may have a cryptocrystalline groundmass as distinguished from pure obsidian (felsic) or tachylyte (mafic), which are natural rock glasses.