The Devonian: Age of Fishes

• In search of our origins
  • Records of past life
    • The notion of geologic time
    • The history of the Devonian System
  • Witnesses to evolution
  • A lost world
    • Tectonic context
    • Paleogeography
    • Climate
    • A Devonian day
  • Life in crisis
    • The Late Devonian extinction event
• The plant world
  • The conquest of land
  • The first forests
  • The plants of Miguasha
    • Protobarinophyton
    • Archaeopteris
    • Spermasporites
    • Spores by the millions
• The animal world
  • Life in the sea
  • The diversification of fish
  • Toward the first tetrapods
  • The animals of Miguasha
    • A window through time
      • Representativity
      • Fossil quality
      • Specimens by the thousands
    • The food chain
      • Of predators and prey
      • Stomach contents
      • Coprolites
    • Invertebrates
      • The aquatic environment
      • Land-based communities
    • Vertebrates
      • Jawless fish
        • Anaspids
        • Osteostracans
      • Jawed fish
        • Placoderms
          • Antiarchs
          • Arthrodires
        • Acanthodians
        • Actinopterygians
        • Sarcopterygians
          • Actinistians
          • Porolepiforms
          • Dipnoi
          • Osteolepiforms
          • Elpistostegalians

The Miguasha Group

Where the Ristigouche River estuary joins the Baie des Chaleurs, its banks are made of sedimentary and volcanic rocks that represent almost the entire Devonian Period.(76 kb) These geologic layers form a large, gently folded U-shaped structure called the Ristigouche Syncline. The southern flank of this structure is found in New Brunswick and the northern flank in Quebec.

The two youngest Devonian rock formations in the region are the Fleurant and Escuminac formations, both located in the Miguasha area on the Quebec side. These two formations are always found together, and even have a similar mode of deposition. This intimate association is underscored by the union of these stratigraphic units into a single geological group, the Miguasha Group.

The Miguasha Group is particularly well exposed along the coastal cliffs at the southern tip of Miguasha Point, and on Pointe à Fleurant at the eastern extremity of the municipality of Escuminac.

(52 kb)The notion that the Miguasha Group only outcrops in this one geographic area has persisted for more than a century. But recent discoveries of Fleurant and Escuminac outcrops have been made at the eastern tip of the Ristigouche Syncline, north of Miguasha Point, and 40 km further east in the valley of the Grande Cascapédia River near New Richmond. These discoveries have forced geologists to change their earlier perception.

(44 kb)The Escuminac and Fleurant formations were part of an extensive sedimentary system that formed while the Appalachian Mountains were still in their final stages of uplift. The ancient Miguasha estuary covered a large area along the margin of the young mountain chain, so perhaps it is no exaggeration to compare this estuary to those of the Mississippi, the Amazon, or even the Nile. The ancient estuary occupied a lowlands zone, which later hosted a great alluvial plain that extended into an arm of the sea during the Carboniferous Period.

Miguasha: A story written in stone

• The Gaspé Peninsula: A world of oceans and mountains
  • The birth of the Appalachians
  • The closing of an ocean
  • A sea of fossils
  • Faunal realms
  • Devonian lands in the Gaspé Peninsula
• The Miguasha Group
  • The Fleurant Formation
  • The Escuminac Formation
    • Geological characteristics
    • Localization systems
    • Biostratigraphy
    • An ancient estuary
    • An environment of exceptional preservation
• Of cliffs and men
  • The Seigniory of Shoolbred
  • A World Heritage Site
  • Miguasha fossils around the world
  • The geology craze of the 19th century
  • The first discoveries
  • Scientists come to Miguasha
  • Links to Scotland
  • Local fossil hunters
  • Erik Jarvik and the Prince of Miguasha
  • The birth of the Miguasha project
  • The 1991 International Symposium
• Le Parc national de Miguasha
  • Protecting a unique heritage
  • Fossil digs and research
  • The on-site museum

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The Miguasha Group
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© Miguasha National Park 2007

Title: The Fleurant Formation and its contact with the Escuminac Formation
Author: Parc national de Miguasha
Sources: Parc national de Miguasha
Year: 2002

Description:
This photo shows the contact between the conglomerate of the Fleurant Formation (bottom) and the lowermost sandstone beds of the overlying Escuminac Formation. The rounded pebbles and cobbles were derived from the erosion of Ordovician and Siluro-Devonian sedimentary beds that were exposed north of the Miguasha area at that time. The Fleurant and Escuminac sedimentary formations constitute the geological Miguasha Group.

Title: The Restigouche syncline
Author: François Bienvenue
Sources: Parc national de Miguasha
Year: 2007

Description:
Simplified geology of the Restigouche River. The Miguasha Group that includes the fossiliferous Escuminac Formation crops up in the eastern section of a long syncline, a basin-shaped fold that affects the sedimentary layers in the region. The axis of this structure runs through the Restigouche River between Quebec and northern New Brunswick.

Title: Distribution of the Miguasha Group
Author: François Bienvenue
Sources: Parc national de Miguasha
Year: 2007

Description:
Location of the principle outcrops of the Miguasha Group along Quebec’s boundaries in Baie-des-Chaleurs. The recent discovery of the Fleurant and Escuminac formations in the New Richmond area east of Miguasha involves a very extensive sedimentary system.