Search results
Results from the WOW.Com Content Network
The Green River Formation is an example of a prominent freshwater sedimentary formation containing numerous limestone beds. [70] Freshwater limestone is typically micritic. Fossils of charophyte (stonewort), a form of freshwater green algae, are characteristic of these environments, where the charophytes produce and trap carbonates. [71]
Purbeck Marble – Fossiliferous limestone found in the Isle of Purbeck, Dorset, England (not a "true marble"; fossiliferous limestone) Sussex Marble – Limestone Pages displaying wikidata descriptions as a fallback Pages displaying short descriptions with no spaces (not a "true marble"; fossiliferous freshwater limestone)
Tufa columns at Mono Lake, California. Tufa is a variety of limestone formed when carbonate minerals precipitate out of water in unheated rivers or lakes. Geothermally heated hot springs sometimes produce similar (but less porous) carbonate deposits, which are known as travertine or thermogene travertine.
Travertine terraces at Mammoth Hot Springs, Yellowstone National Park, in 2016 Calcium-carbonate-encrusted, growing moss in a low-temperature freshwater travertine formation (1 euro coin for scale) Travertine (/ ˈ t r æ v ər t iː n / TRAV-ər-teen) [1] is a form of terrestrial limestone deposited around mineral springs, especially hot ...
The Sacred Cenote at Chichen Itza, Mexico. Cenotes are surface connections to subterranean water bodies. [5] While the best-known cenotes are large open-water pools measuring tens of meters in diameter, such as those at Chichen Itza in Mexico, the greatest number of cenotes are smaller sheltered sites and do not necessarily have any surface exposed water.
A freshwater lens on an island. In hydrology, a lens, also called freshwater lens or Ghyben-Herzberg lens, is a convex layer of fresh groundwater that floats above the denser saltwater and is usually found on small coral or limestone islands and atolls.
East Kirkton Quarry, or simply East Kirkton, is a former limestone quarry in West Lothian, Scotland, now a renowned fossil site.The quarry is known for terrestrial and freshwater fossils about 335 million years old, from the late Viséan stage of the Mississippian subperiod (Early Carboniferous Period).
Marl ponds of the northeastern United States are often kettle ponds in areas of limestone bedrock that become poor in nutrients (oligotrophic) due to precipitation of essential phosphate. Normal pond life is unable to survive, and skeletons of freshwater molluscs such as Sphaerium and Planorbis accumulate as part of the bottom marl. [13]