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Spheroidal weathering is the result of chemical weathering of systematically jointed, massive rocks, including granite, dolerite, basalt and sedimentary rocks such as silicified sandstone. It occurs as the result of the chemical alteration of such rocks along intersecting joints.
It is quite common for spheroidal weathering, a form of chemical weathering, to occur as groundwater circulates through orthogonal joint sets in the near-surface. [10] This process results in the alteration and disintegration of bedrock adjacent to the joints.
Weathering is relatively slow, with basalt becoming less dense, at a rate of about 15% per 100 million years. The basalt becomes hydrated, and is enriched in total and ferric iron, magnesium, and sodium at the expense of silica, titanium, aluminum, ferrous iron, and calcium.
The use of weathering rinds in relative dating is widely used in Arctic, Antarctic, and alpine regions and in the correlation of glacial moraines and tills and fluvial sediments and terraces. [6] [7] [8] In addition, weathering rinds have been used to determine the absolute amount of time gravel-size rock has been exposed to the weathering ...
At one site (Ubeidiya prehistoric site near the Sea of Galilee, 1.4 million years old) around 600 baseball-sized spheroids of limestone, basalt, and flint have been found, and it has been demonstrated that they were not simply hand axes that became spherical through use, but were deliberately made as spheres.
They usually form early in the burial history of the sediment, before the rest of the sediment is hardened into rock. This concretionary cement often makes the concretion harder and more resistant to weathering than the host stratum. There is an important distinction to draw between concretions and nodules. Concretions are formed from mineral ...
Mysterious tar balls washed up on several Florida beaches, forcing closures and triggering an investigation by the U.S. Coast Guard. Fort Lauderdale’s shoreline was among the most impacted ...
Watson Lake in the Granite Dells The Peavine Trail Dells Granite showing spheroidal weathering.. The Granite Dells is a geological feature north of Prescott, Arizona.The Dells consist of exposed bedrock and large boulders of granite that have eroded into an unusual lumpy, rippled appearance.