Introduction

Three hundred and eighty million years ago, a barrier reef stretching 1,400 kilometres along the margin of the Gondwana supercontinent lay submerged beneath a warm tropical sea in what is now the Kimberley region of Western Australia. Today that reef stands as limestone ranges rising abruptly from the spinifex plains, carved by rivers into spectacular gorges that are among the most visited natural features in northern Australia. The rock walls of Windjana Gorge and the river cliffs of Geikie Gorge are built from the fossilised remains of that ancient reef: corals, stromatoporoids, brachiopods, crinoids, and the armoured fish that lived in the reef lagoon. The Gogo Formation, deposited in the deep-water basin behind the reef at the same time, is recognised globally as the world’s most significant Devonian fish site, a Konservat-Lagerstatte where three-dimensional soft tissue preservation has revealed muscles, nerves, embryos with umbilical cords, and internal organs that are not preserved anywhere else on Earth. Access to the primary Gogo fossil-bearing beds requires permission from private station owners and is not a general public visiting option. However, the fossiliferous Devonian reef rock is on full display at two publicly accessible national parks — Windjana Gorge and Geikie Gorge — where you can walk among the actual reef structures and see fossil corals and invertebrates preserved in the gorge walls. This guide covers both the public gorge sites and the geological significance of the broader Gogo system.

Location and Directions

Address

Windjana Gorge National Park is located on the Gibb River Road, approximately 145 km east of Derby, Western Australia. Geikie Gorge National Park is located 18 km northeast of Fitzroy Crossing on Geikie Gorge Road, Western Australia.

Directions

For Windjana Gorge: from Derby, drive east on the Gibb River Road. The turnoff to Windjana Gorge National Park is on the left approximately 119 km from Derby, then a further 23 km on an unsealed access road to the car park. A four-wheel-drive vehicle is recommended after rain. The Gibb River Road is typically open from April to October; it closes in the wet season. The car park has toilet facilities and a ranger station. Camping is available at the national park campground; fees apply and bookings are required through the Western Australian Department of Biodiversity, Conservation and Attractions (DBCA). For Geikie Gorge: from Fitzroy Crossing, drive northeast on Geikie Gorge Road for 18 km to the car park. The road is sealed. Fitzroy Crossing is on the Great Northern Highway approximately 250 km east of Derby. The car park has toilets, shaded picnic tables, and ranger facilities. A 1.3 km walking track runs along the western bank of the Fitzroy River through the gorge. Boat tours of the gorge are conducted by Bunuba Traditional Custodians and are the best way to view the cliff faces and their fossil content from the water. Both sites are within the broader Kimberley region; the nearest major service centres are Broome (to the west) and Kununurra (to the east).

What Fossils You’ll Find

At Windjana Gorge and Geikie Gorge, you are walking through a fossilised reef that is in situ — the ancient organisms are still in the positions where they grew and died 380 million years ago. The gorge walls are studded with fossil corals (rugose and tabulate forms), stromatoporoids (sponge-like colonial organisms that formed the main reef framework), brachiopods, crinoid stem segments, and bryozoans. In some areas you can see cross-sections through the original reef structure, with back-reef lagoonal sediments distinguishable from the reef-front talus. Freshwater crocodiles (Crocodylus johnstoni) live in Geikie Gorge and are visible from the walking track and boat tours — a reminder that the gorges remain ecologically active systems. The most scientifically significant fossils from this geological system — the three-dimensional fish, soft-tissue-preserved placoderms, and diverse lungfish of the Gogo Formation — come from limestone concretions found on Gogo Station and Fossil Downs Station, both private cattle properties that require individual permission to access. Those concretions, when acid-prepared, yield complete fish bodies with preserved muscles, blood vessels, and embryos, including Materpiscis attenboroughii, the first vertebrate known to give birth to live young. Prepared specimens are held at the Western Australian Museum in Perth and the Natural History Museum in London; both institutions display Gogo material in their permanent palaeontology galleries.

Geologic History

The Ancient Environment

The Gogo Formation and the surrounding Lennard Shelf reef complex date to the Late Devonian, specifically the Frasnian Stage, approximately 380 to 384 million years ago. At that time, the Kimberley region sat at tropical latitudes and was submerged beneath a warm, shallow epicontinental sea. A barrier reef roughly equivalent in scale to the modern Great Barrier Reef extended for 1,400 kilometres along the Gondwana margin, separating a shallow lagoon to the south from a deeper, quieter basin to the north. The Gogo Formation accumulated in this deep basin. When fish died in the reef and lagoon waters, they sank to the anoxic seafloor of the basin — conditions with no dissolved oxygen meant that bacteria could not decompose the bodies quickly. Calcium carbonate precipitated around the fish before decay was complete, encasing complete three-dimensional carcasses in limestone nodules. The extreme preservation of soft tissues resulted from this combination of rapid encasement and minimal bacterial activity. The reef complex was buried by later sediments, then progressively exhumed by erosion over hundreds of millions of years. The Fitzroy River and its tributaries cut down through the limestone, exposing the reef faces as the dramatic gorge walls visible today.

How the Gogo Formation Became a Fossil Viewing Site

Cephalopod fossils from the Kimberley reef complex were first described scientifically in 1890. Systematic collection from the Gogo Station concretions began in the 1940s and accelerated dramatically in 1963 when Harry Toombs of the Natural History Museum in London developed the acid preparation technique — dissolving limestone nodules in dilute formic or acetic acid to expose pristine fossil surfaces. This technique transformed Gogo from a moderately interesting site into the world’s most important window on Devonian vertebrate anatomy. Over 60 major scientific papers have described material from the formation. The Windjana and Geikie gorge areas were designated national parks to protect the reef landscapes and their cultural significance to the Bunuba people, whose country encompasses the gorges. Public access to the gorges has been managed through the national park system since the 1970s.

Visiting Rules and Regulations

Is Fossil Collecting Allowed?

Fossil collecting is not permitted at Windjana Gorge National Park or Geikie Gorge National Park. All geological and biological material within national parks in Western Australia is protected under the Conservation and Land Management Act 1984 (WA) and the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). Removing any rock, fossil, or mineral from a national park is an offence. The Gogo Formation fossil-bearing concretions on private station land are protected as a Category A State Fossil Site under the Western Australian Museum Act 1969, which requires a ministerial permit for any collection. Visitors to Windjana Gorge and Geikie Gorge may observe and photograph fossil invertebrates in the gorge walls freely. Entry fees and camping fees apply; check current rates with DBCA before visiting.

Recommended Equipment

The Kimberley is one of Australia’s most remote and demanding environments. For visiting between April and October (dry season), carry a minimum of three litres of water per person per day when walking. A hat, sunscreen with SPF 50+, and long-sleeved light clothing protect against intense UV radiation. Closed-toe shoes with good grip are essential on the uneven gorge floor. A basic first-aid kit is advisable. For overnight stays at Windjana Gorge campground, bring a fly net for your sleeping area as insects can be heavy near the river. Fuel up in Derby before travelling the Gibb River Road; the distance between reliable fuel stops is substantial.

Safety

Both gorges have permanent water and are home to freshwater crocodiles (Crocodylus johnstoni). Freshwater crocodiles rarely attack humans unless provoked, but do not swim in gorge pools, do not approach crocodiles on the bank, and keep children and dogs clear of the water’s edge. Saltwater crocodiles (Crocodylus porosus) can also move into the Fitzroy River system during the wet season; the CrocWise guidelines from the Western Australian Department of Biodiversity, Conservation and Attractions apply throughout the Kimberley. Flash flooding is possible after rain in the gorges even when skies above appear clear; check weather forecasts and do not enter narrow gorge sections during or after rain. Flies are abundant from March to October; carry insect repellent and a fly net. Mobile phone coverage in the Kimberley is extremely limited — a personal locator beacon (PLB) is recommended for any travel on the Gibb River Road.

Sources

• https://www.dbca.wa.gov.au/parks/windjana-gorge-national-park
• https://www.dbca.wa.gov.au/parks/geikie-gorge-national-park
• https://www.museum.wa.gov.au/research/collections/earth-and-planetary-sciences/palaeontology/gogo-formation
• https://en.wikipedia.org/wiki/Gogo_Formation
• https://en.wikipedia.org/wiki/Windjana_Gorge_National_Park
• https://en.wikipedia.org/wiki/Geikie_Gorge_National_Park
• https://en.wikipedia.org/wiki/Materpiscis
• https://en.wikipedia.org/wiki/Devonian_reef

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