Archivo: Stromatolites in limestone, Going-to-the-Sun Highway, Glacier NP

Descripción: Stromatolitic limestone - numerous columnar stromatolites in Precambrian limestone at Glacier National Park, Montana, USA. Stratigraphy: Helena Formation (Siyeh Formation), Belt Supergroup, Mesoproterozoic, ~1.45 Ga Locality: roadcut on northern side of Going-to-the-Sun Highway (0.9 km east of NE corner of parking lot for Logan Pass visitor center), Glacier National Park, northwestern Montana, USA. Stromatolites are large, layered structures built up by mats of cyanobacteria. Stromatolites vary in appearance, ranging from slightly wrinkled horizontal laminations in sedimentary rocks to low mounds to prominent mounds to columnar structures and other forms. Stromatolites are most common in the Proterozoic fossil record. They are scarce today, but famous modern examples occur at Shark Bay, Western Australia.
Título: Stromatolites in limestone, Going-to-the-Sun Highway, Glacier NP
Créditos: Stromatolites in limestone (Helena Formation (a.k.a. Siyeh Formation), Belt Supergroup, Mesoproterozoic, about 1.45 Ga; Going-to-the-Sun Highway, Glacier National Park, Montana, USA) 4
Autor(a): James St. John
Términos de Uso: Creative Commons Attribution 2.0
Licencia: CC BY 2.0
Enlace de Licencia: https://creativecommons.org/licenses/by/2.0
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