The Iapetus Ocean was an ocean that existed in the late Neoproterozoic and early Paleozoic eras of the geologic timescale. The Iapetus Ocean was situated in the southern hemisphere, between the paleocontinents of Laurentia, Baltica and Avalonia. The ocean disappeared with the Acadian, Caledonian and Taconic orogenies, when these three continents joined to form one big landmass called Euramerica. The "southern" Iapetus Ocean has been proposed to have closed with the Famatinian and Taconic orogenies, meaning a collision between Western Gondwana and Laurentia.
Avalonia was a microcontinent in the Paleozoic era. Crustal fragments of this former microcontinent underlie south-west Great Britain, southern Ireland, and the eastern coast of North America. It is the source of many of the older rocks of Western Europe, Atlantic Canada, and parts of the coastal United States. Avalonia is named for the Avalon Peninsula in Newfoundland.
New Chelsea-New Melbourne-Brownsdale-Sibley's Cove-Lead Cove is a local service district and designated place in the Canadian province of Newfoundland and Labrador.
The Chamberlain's Brook Formation is a thin but distinctive geologic formation of dark red calcareous mudstones that crops out from Rhode Island to Massachusetts and, Nova Scotia, New Brunswick and Newfoundland. It preserves fossils, including trilobites, dating back to the lower mid-Cambrian period. Its lowermost member is the Braintree Member and the uppermost member is the Fossil Brook Member.
The Brigus Formation is a fossiliferous upper lower Cambrian geologic formation in Newfoundland and Labrador.
The Conception Group is a geologic group in Newfoundland and Labrador. It preserves fossils dating back to the Ediacaran period. It mainly contains turbidites, but is interrupted by a glacial diamictite, and tops out with sand and siltstones. It corresponds to the lower portion of the Connecting Point Group.
The St John's Group is a fossiliferous shale-dominated Ediacaran geologic group in Newfoundland and Labrador, younger than 565 ± 3 million years ago.
The Random Formation is a rock unit in Newfoundland dating to the early Cambrian period, dominated by tidal quartz arenites deposited in a near-shore environment, but also incorporating intertidal and open-shelf deposits, including glauconitic and mud-cracked mudstones, and red channel sandstones. It was deposited quickly and is approximately 175 m thick. The Blue Pinion Formation was originally recognized as a separate formation, but is now interpreted as an expression of the Random Formation.
The Smith Point Formation is an Early Cambrian, fossil-rich, pink to brick red limestone formation cropping out in Newfoundland.
Crown Hill Formation is a late Ediacaran volcanic non-marine sedimentary formation in Newfoundland. It's topped off with a bright red conglomerate, with silt and arkose sands of similar hue too.
Young's Cove Group is a stratigraphic group covering the Ediacaran-Cambrian boundary (in the Chapel Island Formation, cropping out on the Burin Peninsula and elsewhere in Newfoundland.
The Marystown Group is a Neoproterozoic stratigraphic group of predominantly volcanic sediments – subaerially deposited ash flow tuffs from rhyolites and alkali basalts, with a central sandstone unit, cropping out in Newfoundland.
The Harcourt Group is a stratigraphic group of siliciclastic rocks deposited in the Gondwanan Margin, cropping out in the Avalon Zone of Newfoundland.
The Signal Hill Group is a siliciclastic Group of marine Ediacaran strata, cropping out in Newfoundland, in the eastern Bonavista Peninsula and the eastern Avalon peninsula.
The Musgravetown Group is a terminal Ediacaran stratigraphic group of terrestrialish sandstones, lavas and tuffs cropping out in Newfoundland.
The Love Cove Group is a metamorphosed volcaniclastic sedimentary group cropping out in southeastern Newfoundland. Strata from towards the middle of the formation have been dated to 620 ± 1 million years ago.
The Bull Arm Formation is a volcanic formation cropping out in Newfoundland, the youngest of the Musgravetown Group. It is defined as everything between the first and last volcanic horizon, with a recognition that some sandstones will be interbedded, and its start and finish may vary across the region depending on how widespread volcanic horizons are in practice.
The Heart's Desire Formation is a formation of 'olive-green' sandstones cropping out in Newfoundland.
The geology of Saint Pierre and Miquelon is part of the 680 to 550 million year old, late Proterozoic Avalon Zone, a part of the Canadian Appalachians. The oldest rocks are 615 million year old metasedimentary and metavolcanic rocks, intruded by diorite and trondhjemite in the Cap de Miquelon Group. The metamorphic rocks are descended from an earlier volcanic arc-marine platform, rather than more ancient basement rock from the Avalonia microcontinent. The St. Pierre Group formed 581 million years ago with felsic and pyroclastic flows. Together with mafic rocks and andesite, they are evidence of back arc environment. The late Neoproterozoic Belle-Riviere Group includes bimodal volcanic rocks such as basalt and rhyolite overlain by terrestrial sedimentary rock. Belle-Riviere Group rocks partially overlie the Tommotian Fortune Group and the early and middle Cambrian Langlade Group, which have fossiliferous limestone beds and siltstone. Discordant contact between older Precambrian rocks and Paleozoic sedimentary rocks as well as thrust faults indicate Acadian orogeny related deformation.
The geology of Newfoundland and Labrador includes basement rocks formed as part of the Grenville Province in the west and Labrador and the Avalonian microcontinent in the east. Extensive tectonic changes, metamorphism and volcanic activity have formed the region throughout Earth history.
Newfoundland 
Canada 
