Discover Canada and Explore the Fossils and Geodiversity of Joggins Fossil Cliffs in Nova Scotia
- Wayne Munday
- 24 minutes ago
- 5 min read
Sip back and discover Canada and explore the fossils and geodiversity of Joggins Fossil Cliffs located along the Atlantic coast of Nova Scotia. Designated a UNESCO World Heritage Site in 2008 the cliffs have also been recognised in 2022 by the International Union of Geological Sciences (IUGS) as one of the “First 100 Geological Heritage Sites” worldwide. Joggins Fossil Cliffs is often called the “Coal Age Galápagos” and preserves one of the world’s most remarkable records of terrestrial life during the Pennsylvanian Subperiod of the Late Carboniferous around 323–299 million years ago. Stretching 14.7 kilometres along Chignecto Bay within the Cumberland Basin these cliffs are part of the Bay of Fundy coast, where extreme tides continually reveal fresh exposures of the Joggins Formation. Deposited near the equator during the assembly of Pangea, this 1.5-kilometre-thick sequence of coal, sandstones, shales, and mudstones records tropical forests, peat swamps, and deltaic environments shaped by salt tectonics in the Athol Syncline. Joggins is known for its upright fossilised lycopsid trees and the discovery of Hylonomus lyelli, the earliest known reptile, a key milestone in vertebrate evolution. The cliffs also preserve diverse amphibians, giant arthropods like Arthropleura, and more than 200 plant and animal species. Recognised as a UNESCO World Heritage Site, Joggins offers the visitor an exceptional geological, evolutionary, and cultural heritage experience within this Mi’kmaq traditional territory.
Often referred to as the “Coal Age Galápagos,” Joggins preserves an extraordinary record of terrestrial life during the Pennsylvanian Subperiod of the Late Carboniferous between 323 –299 million years ago. The cliffs extend approximately 14.7 kilometres along Chignecto Bay within the Cumberland Basin, part of the broader Maritimes Basin complex. This region lies on the shores of the Bay of Fundy, an area noted for some of the world’s highest tides, which continually exposes fresh fossils. Joggins is also embedded within the traditional territory of the Mi’kmaq, Indigenous inhabitants of Nova Scotia. The name “Joggins” is likely derived from the Mi’kmaq word Chegoggin, meaning “place of fish weirs” reflecting the region’s waterways.
The Joggins Formation is a globally significant Pennsylvanian (Westphalian Stage) sedimentary sequence renowned for both its exceptional fossil preservation and coal deposits. This 1.5 kilometre-thick formation lies within the Cumberland sub-basin of the Maritimes Basin, deposited near to the equator during the Late Carboniferous as part of Pangea.
The region once hosted tropical rainforests, peat swamps, estuaries and river channels and experienced periodic marine incursions shaping this coastal landscape. Syndepositional subsidence driven by the withdrawal of salt enabled rapid sediment accumulation preserving polystrate lycopsid trees in an upright position encased within more than one layer of rock, alongside a rich fossil assemblage.
The geology of the Joggins Formation comprises of interbedded coal, mudstones with fossilised root structures, sandstone, claystone and organic-rich shales. Found at the base of sandstone beds are the signatures of flute casts and tool marks produced by erosion and sediment filling from the movement of water. Flute casts are scoop-shaped hollows created by eddies in currents with the pointed end indicating upstream direction. Tool marks result from coarser debris like rocks or sticks, bouncing, rolling, or scraping along soft sediment, leaving grooves, scratches, or bounce marks that record the flow and energy of past currents.
The geology of Joggins Fossil Cliffs shows an environment of alternating cycles of transgression and regression Pennsylvanian sea levels while regional tectonics and uplift tilted the strata along the Athol Syncline have created the striking vertical cliffs exposed by the erosive power of the Bay of Fundy.
The Athol Syncline located within the Cumberland Basin formed during the late Paleozoic as a result of salt tectonics or halokinesis. This is the movement of the underlying evaporite layers that cause subsidence in the synclinal area while simultaneously uplifting nearby anticlines creating a structural depocentre that trapped vast amounts of sediment.
During the Pennsylvanian Age this process provided the space necessary for the accumulation of the thick coal-bearing strata of the Joggins Formation. The dynamics of salt withdrawal not only shaped the geology of the Cumberland Basin but also played a critical role in preserving the Carboniferous ecosystems that thrived in tropical swamps and floodplains. As a result, the Athol Syncline remains a key feature in understanding both coal formation and the geological history of eastern Canada.
Scientific interest in Joggins began in the early 19th century. Observers such as Abraham Gesner, Charles T. Jackson, and by Sir Charles Lyell a prominent British geologist and Sir John William Dawson a Canadian geologist collaborated on fieldwork in the Joggins Formation. They revealed not only a Carboniferous ecosystem but through the fossil record also the origins of amniotes.
Amniotes are vertebrates that includes reptiles, birds and mammals that share the evolutionary adaptation of having the amniotic sac. This protective membrane surrounds the embryo and provides a self-contained aquatic environment allowing reproduction to take place entirely on land. First appearing in the Carboniferous Period amniotes overcame the reproductive constraints of their amphibian ancestors by eliminating the need for a aquatic larval stage for egg development and hatching.
Their success was further supported by traits such as keratinised, water-resistant skin, rib-based lung ventilation, and specialised skull structures with temporal openings that enhanced jaw strength. These adaptations enabled amniotes to colonise and evolve in diverse terrestrial habitats like Carboniferous forests. Divided into two major lineages, firstly the Synapsids (Greek for "fused arch"), which gave rise to mammals, and secondly the Sauropsida (Greek for "lizard faces"), which include reptiles and birds. The emergence of Amniotes is among the most important evolutionary milestones in Earth’s history.
The fossil record of Joggins Fossil Cliffs includes over 200 species of plants, invertebrates, and vertebrates. True dinosaurs are absent from Joggins as the cliffs predate the Mesozoic by over 100 million years. The prominent fossils are the standing lithified trees that include the lycopsid Sigillaria and group of tall arborescent trees called Cordaites that flourished in wet and peat-forming habitats along with Club Mosses. Interestingly, many of these trees have hollows out providing a rare microhabitat where fossilised tree-hollow fauna are found.
A wide range of animals depend on natural tree cavities for survival and these hollows provide essential shelter. Among the fossils found in the tree-hollow fauna at Joggins have been tetrapod's, primitive insects and the gastropod Dendropupa vetusta the first known land snail. Among the vertebrates and the most celebrated discovery is Hylonomus lyelli, the earliest known amniotic reptile entombed within a fossil tree trunk and dating to between approximately 312 - 315 million years old.
In addition to Hylonomus, Joggins Fossil Cliffs preserves early amphibians including extinct microsaurs (“small lizards”) and larger labyrinthodonts (“maze-toothed” amphibians). Trace fossils, such as trackways provide further evidence of terrestrial activity showing how organisms moved across these ancient landscapes including the giant extinct millipede Arthropleura a terrestrial myriapod growing up to two meters in length.
The Joggin Fossil Cliffs as an UNESCO World Heritage Site is a protected coastal landscape including foreshore exposures, beache, and rock platforms. Public access is carefully managed to balance scientific preservation with educational and tourism opportunities. Fossil collection requires a Heritage Research Permit from the Province, and guided tours, educational programs, and the Joggins Fossil Centre help visitors understand the cliffs’ significance. The Bay of Fundy’s tides continually expose fresh fossil discoveries. This combination of natural erosion, careful management, and active research ensures that Joggins remains a living laboratory to experience when understanding Carboniferous life and early terrestrial ecosystems.
