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The Chazy Reef Formation is a mid-Ordovician limestone deposit in northeastern North America. It consists of some of the oldest reef systems built by a community of organisms [ 1 ] rather than the deposit of a limited range of similar organisms, such as Stromatolite mounds deposited by ancient cyanobacteria.
The earliest phase of the seaway began in the mid-Cretaceous when an arm of the Arctic Ocean transgressed south over western North America; this formed the Mowry Sea, so named for the Mowry Shale, an organic-rich rock formation. [1] In the south, the Gulf of Mexico was originally an extension of the Tethys Ocean. In time, the southern embayment ...
Moonstone cabochon. The most common moonstone is of the orthoclase feldspar mineral adularia, named for an early mining site near Mt. Adular in Switzerland, now the town of St. Gotthard. [1] [better source needed] A solid solution of the plagioclase feldspar oligoclase +/− the potassium feldspar orthoclase also produces moonstone specimens.
Lake islands of North America: Atlin Lake, Theresa Island, highest elevation inside a freshwater lake in North America at 2059m; Lake Huron. Manitoulin Island, world's largest inland island; Saint Joseph Island, world's 8th largest inland island; Drummond Island, world's 9th largest inland island; Thirty Thousand Islands; Lake Superior
The Mid-Pacific Mountains (MPM) is a large oceanic plateau located in the central North Pacific Ocean or south of the Hawaiian–Emperor seamount chain.Of volcanic origin and Mesozoic in age, it is located on the oldest part of the Pacific Plate and rises up to 2 km (1.2 mi) (Darwin Rise) above the surrounding ocean floor and is covered with several layers of thick sedimentary sequences that ...
The North Atlantic Igneous Province (NAIP) is a large igneous province in the North Atlantic, centered on Iceland. In the Paleogene , the province formed the Thulean Plateau , a large basaltic lava plain , [ 1 ] which extended over at least 1.3 million km 2 (500 thousand sq mi) in area and 6.6 million km 3 (1.6 million cu mi) in volume. [ 2 ]
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The island of Aruba formed within the past 145 million years, beginning in the Cretaceous, as part of the Lesser Antilles island arc. The island is built on a thick sequence of volcanic rock, but also has carbonate sediment deposits because it was submerged for parts of its existence.