The Cambrian System of Wyoming

Ga Grenville orogen: Continent-continent collision Continent-continent collision of Laurentia with African and of Laurentia with African and South American cratons; South American cratons; SE transfer of Caborca block SE transfer of Caborca block

Ga Grenville orogen: Granitoids intrude juvenile Granitoids intrude juvenile belts as far west as Colorado belts as far west as Colorado

Life may have survived a cataclysmic global freeze some 700 million years ago in pockets of open ocean. Snowball Earth as hypothesized during the Sturtian Glaciation 700 million years ago

Laurentia Siberia Baltica Pannotia- Gondwana Panthalassian ocean n Rodinia rifted in Neoproterozoic creating large Paleozoic continents All continents had rifted passive margins, and developed broad continental shelves during the Cambrian through the middle Ordovician. Iapetus Prototethys

SAUK Supersequence TIPPECANOE Supersequence

Laurentia Late Proterozoic (Ediacaran) 600 mya Iapetus Iapetus Gondwana Baltica

Middle Cambrian 530 mya Global Sea level rise began in the Late Ediacaran Period and continued throughout the Cambrian, flooding interiors of continents, including Laurentia, depositing continental shelf and epicontinental sea deposits of the North American Sauk Supersequence. Laurentia

Late Cambrian 500 mya Global Sea level rise began in late Ediacaran Period and continued throughout the Cambrian, flooding interiors of continents, including Laurentia, depositing continental shelf and epicontinental sea deposits of the North American Sauk Supersequence. Laurentia

Cordilleran Orogen: Cambrian passive margin

Flat Head Formation n Brown Sandstone n Quartz Arenite, Medium Bedded, Cross bedded. n Lesser Green Shale and Mudstone n Lesser Micritic Limestone n Some Glauconite n Linguloid Brachiopods

Gallatin and Gross Ventre Formations n Poorly exposed, valley former between resistant Paleozoic and Basement rocks. n Thin bedded, structurally incompetent. n Interbedded shale, limestone, and sandstone n Limestones are micritic, trace fossils are common, lots of intraclasts. n Greener at the base (Gros Ventre), Pinker at the top (Gallatin).