[citation needed] In the late Precambrian and Paleozoic, Avalonia (named after the Avalon Peninsula in Newfoundland) formed as a volcanic island arc off the coast of the supercontinents Pannotia which lost land through rifting and became Gondwana.
Northwest Newfoundland includes older rocks affected by the Grenville orogeny in the late Proterozoic during the collision of continents to form the previous supercontinent Rodinia.
[citation needed] Examples of ancient rocks from this period include the late Precambrian Harbour Main Group ignimbrite and ash flow tuff with obsidian and augite in the center of the Avalon Peninsula.
[3] Northern Newfoundland at the edge of the Laurentian continent witnessed columnar flood basalts in the Cloud Hills area into the Cambrian.
[4] The Avalon Zone is an area of 550 million year old sedimentary and volcanic rocks exposed only in the east that preserves the original geology of the microcontinent and extends 600 kilometers out to sea forming the below water Flemish Cap.
[citation needed] By the early Devonian, the Avalonia microcontinent and the Bronson Hill island arc, collided with Laurentia to form the mid-sized continent Euramerica, causing the Taconic orogeny.
By 356 million years ago, Gondwana collided with Euramerica, closing the Rheic Ocean and creating the supercontinent Pangea, which left Newfoundland and the Avalonian microcontinent (also known as terrane) far inland and brought widespread interior desert conditions around the world.
Archean age rocks and east-west structural trends mark the Superior Province (a small area in the west near Quebec) which encompasses the Ashuanipi Complex granulite and granodiorite intruded by pyroxene-rich felsic plutons.
The Nain Province is subdivided into the Makkovik-subprovince, which is mainly made up of the 25,000 foot thick Aillik Group quartzofeldspathic, argillite, limestone, conglomerate, paragneiss and iron formations.
Structural geologists divide it into the undeformed sedimentary and volcanic rocks Kaniapiskau Supergroup in the Labrador Trough (including gabbro sills and plutons) in the west and high-grade anorthosite and gneiss in the east.
[6] Through the Mesozoic and into the Cenozoic, the landscape eroded, shedding sand into the Labrador Shelf, mainly from older metasediments and metavolcanic rocks that reached amphibolite grade on the sequence of metamorphic facies.