Pircancha Formation | |
---|---|
Stratigraphic range: Floian-Dapingian ~ | |
Type | Geological formation |
Thickness | 1,800 m (5,900 ft) |
Lithology | |
Primary | Mudstone |
Other | Shale, sandstone, pyrite |
Location | |
Coordinates | 21°00′S65°00′W / 21.0°S 65.0°W |
Approximate paleocoordinates | 45°18′S129°06′W / 45.3°S 129.1°W |
Region | Tarija Department |
Country | Bolivia |
The Pircancha Formation is a Floian to Dapingian geologic formation of southern Bolivia. The green mudstones, shales and sandstones were deposited in a shallow to open marine environment. [1] [2] The fossil Pircanchaspis rinconensis is named after the formation.
The formation has provided the following fossils:
The Fezouata Formation or Fezouata Shale is a geological formation in Morocco which dates to the Early Ordovician. It was deposited in a marine environment, and is known for its exceptionally preserved fossils, filling an important preservational window beyond the earlier and more common Cambrian Burgess shale-type deposits. The fauna of this geological unit is often described as the Fezouata biota, and the particular strata within the formation which exhibit exceptional preservation are generally termed the Fezouata Lagerstätte.
The Malargüe Group is a group of geologic formations of the Neuquén Basin of the Mendoza, Neuquén, Río Negro and La Pampa Provinces in northern Patagonia, Argentina. The formations of the Malargüe Group range in age between the middle Campanian to Deseadan, an Oligocene age of the SALMA classification, straddling the Cretaceous–Paleogene boundary, about 79 million to 30 million years in age. The group overlies the older Neuquén Group, separated by an unconformity dated to 79 Ma. The rocks of the Malargüe Group comprise both marine and continental deposits which are over 400 m (1312 ft) thick in total.
The Pissot Formation is a geologic formation in the Armorican Massif of Normandy, northwestern France. It preserves fossils dating back to the Darriwilian to Sandbian stages of the Ordovician period.
The Tufs et calcaires de Rosan is a geologic formation in France. It preserves fossils dating back to the Katian to Hirnantian stages of the Late Ordovician period.
Canaanimico is an extinct genus of medium-sized New World monkeys from the Late Oligocene fossiliferous fluvio-lacustrine Chambira Formation of the Ucayali Basin in Amazonian Peru. The genus was described by Marivaux et al. in 2016 and the type species is C. amazonensis.
The Iscayachi Formation, in older literature also referred to as Guanacuno Formation, is an extensive Tremadocian geologic formation of western and southern Bolivia. The shales and sandstones were deposited in a shallow marine to pro-delta environment. The formation reaches a thickness of 1,000 metres (3,300 ft).
The Obispo Formation is a Dapingian geologic formation of southern Bolivia. The shales and siltstones were deposited in an open marine environment.
The Sella Formation is a Dapingian to Darriwilian geologic formation of southern Bolivia. The grey to green bioturbated siltstones interbedded with thin sandstone layers bear lenticular shell beds. Other parts of the formation contain yellow-green limy shales and grey sandy limestones. Coquinas often fill gutter casts and included brachiopods, trilobites, bivalves and nautiloids. The sediments were deposited in an open marine environment. The species Coxiconchia sellaensis was named after the formation.
The San Benito Formation is a Katian geologic formation of central Bolivia. The formation belongs to the Cochabamba Group, overlies the Anzaldo Formation and is overlain by the Cancañiri Formation. The 500 metres (1,600 ft) thick formation comprises a succession of shallow water quartzitic sandstones with minor interbeds of dark grey micaceous siltstones. Shelly fossils have been found at few horizons and consist mainly of linguliformean brachiopods, bivalves, and a few homalonotid trilobite remains. Poorly preserved graptolites occur occasionally in the shaly beds.
The Cancañiri Formation, also named as Cancañiri Tillite, is a Katian to Hirnantian geologic formation of central Bolivia. The pebbly, argillaceous sandstones, shales and siltstones of the up to 1,500 metres (4,900 ft) thick formation, were deposited in a glacial foreshore to deep water turbiditic environment. The formation is named after Cancañiri, a mining town close to Llallagua, where a local legend of a possessed woman is believed. The formation overlies the San Benito Formation in Cochabamba and the Amutara Formation in other parts. The Cancañiri Formation is overlain by the Uncía Formation.
The Kirusillas Formation is a Homerian geologic formation of central Bolivia. The formation comprises black shales, overlies the Llallagua Formation and is overlain by the Pampa and Guayabillas Formations. The Kirusillas Formation is laterally equivalent to the Lipeón Formation. The formation is a potential source rock for shale oil and shale gas.
The Catavi Formation is a Pridoli to Emsian geologic formation of northern and central Bolivia. The formation comprises a 456 m (1,496 ft) thick succession of fine-grained, olive to brown sandstones and siltstones, shales and black limestones deposited in a shallow to deep marine environment.
The El Molino Formation is a Maastrichtian geologic formation pertaining to the Puca Group of central Bolivia. The formation comprises fine-grained sandstones and sandy limestones with stromatolites deposited in a shallow marine to lacustrine environment. The formation has provided fossils of Dolichochampsa minima, and ichnofossils of Ankylosauria indet., Ornithopoda indet., Theropoda indet. and Titanosauridae indet. The tracksite of Cal Orcko is the best known example of the ichnofossil locations of the formation. The ichnofossil of Ligabueichnum bolivianum may be attributed to an ankylosaur. The fossil fish species Dasyatis molinoensis is named after the formation.
The Venado Formation is a geological formation of the Agua Blanca Group, in the Eastern Ranges of the Colombian Andes, cropping out along the Venado River in northern Huila. The sequence of pyrite containing dark grey micaceous shales interbedded with siltstones and sandstones dates to the Ordovician period; Middle to Late Floian epoch, and has a maximum thickness of 670 metres (2,200 ft) in the type section.
The Lipeón Formation is a Telychian to Pridoli geologic formation of southern Bolivia and northwestern Argentina. The formation comprises sandstones and siltstones. Plant fossils comprising rhyniophytes are scattered throughout, with some abundant concentrations on micaceous bedding plains. The fossil flora is the oldest of South America. Also present were quite diverse small, irregularly branching fragments possibly the tips of algae such as Buthotrephis or Hungerfordia.
The Anzaldo Formation is a Katian geologic formation of central Bolivia. The formation belongs to the Cochabamba Group, overlies the Capinota Formation and is overlain by the San Benito Formation.