The Tererro Formation is a geologic formation in Sangre de Cristo Mountains of New Mexico . It preserves fossils dating back to the early Mississippian .
5-646: The formation is mostly crystalline or calcarenite limestone with a total thickness of up to 130 ft (40 m). It is exposed throughout the Sangre de Cristo Mountains and in the San Luis , Las Vegas-Raton , Palo Duro , and Estancia Basins , as well in the western Tusas Mountains and the Nacimiento Mountains . It lies unconformably on the Espiritu Santo Formation and is unconformably overlain by
10-541: Is a light to medium gray calcarenite, limestone-pebble conglomerate , and finely crystallized locally cherty limestone (thickness 39 feet (12 m)); and the Cowles Member, which is a light yellow gray to olive yellow cross-bedded silty calcarenite (thickness 50 feet (15 m). The Manuelitas Member contains fossils of the foraminiferan Endothyra sp. of Meramecian ( Visean ) age. The Macho, Turquillo, and Manuelitas Members contain microfossils characteristic of
15-597: Is the carbonate equivalent of a sandstone . The term calcarenite was originally proposed in 1903 by Grabau as a part of his calcilutite , calcarenite and calcirudite carbonate classification system based upon the size of the detrital grains composing a limestone. Calcarenites can accumulate in a wide variety of marine and non-marine environments. They can consist of grains of carbonate that have accumulated either as coastal sand dunes ( eolianites ), beaches , offshore bars and shoals, turbidites , or other depositional settings. This article related to petrology
20-837: The Log Springs Formation in the Nacimiento Mountains, the Flechado Formation in the northern Sangre de Cristo Mountains, and the La Pasada Formation in the southern Sangre de Cristo Mountains. The formation is divided into the Macho Member , which is a massive ledge-forming limestone breccia (thickness 30 feet (9.1 m)); the Turquillo Member, a thick-bedded mudstone ; the Manuelitas Member, which
25-852: The Meramecian while the Cowles Member contains microfossils characteristic of the Chesterian (late Visean and Serpukhovian ). The formation was first defined by Baltz and Read in 1960. Armstrong and Mamet included it as the upper formation of their Arroyo Penasco Group in 1974 and added the Turquillo Member. Calcarenite Calcarenite is a type of limestone that is composed predominantly, more than 50 percent, of detrital (transported) sand -size (0.0625 to 2 mm in diameter), carbonate grains. The grains consist of sand-size grains of either corals , shells , ooids , intraclasts , pellets , fragments of older limestones and dolomites , other carbonate grains, or some combination of these. Calcarenite
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