Phillip Island & District Historical Society

500 Million Years of history on Phillip Island

Last updated on 08-Jul-21

July 2015:  Speaker: Member Linda Cuttriss gave a Power Point talk titled: “500 Million Years of History”,based on 500 Million Years on Phillip Island by Linda Cuttriss and Eric Bird (1995).

This is a story of Phillip Island’s natural and human history.  It describes how the island was formed and tells of the close relationship there has always been between the island’s people and its natural environment.


Cambrian Greenstones

This story begins around 500 million years ago in the Cambrian period of geological time when Australia was still part of the mega-continent of Gondwana and the base of Phillip Island was part of a vast mountain range that lay deep beneath the sea. 


Within the ancient mountains were volcanic greenstones, formed when lava burst through the sea floor.  These rocks are found on the shore near Watt Point east of Kitty Miller Bay near where the remains of the Wreck of the Speke still lie. In 1906 the S.S. Speke crashed onto rocks at Watt Point when ploughing through stormy seas on her way to Geelong to load wheat. 


Silurian Sandstones and Mudstones

South of Rhyll, a small outcrop of time-worn sandstone and mudstone dates from the Silurian, over four hundred million years ago, when these were deposits on the floor of the sea.They became layered, folded and uplifted within the mountain range, and have slowly been exposed as rain and rivers washed away the overlying rocks. 


Devonian Granite

In Devonian times, around 360 million years ago, molten rock forced its way up from the Earth’s interior to form a large blister deep beneath the mountains.  It cooled very, very, slowly beneath the ground gradually crystallising into pink granite.  When the mountains were worn down and the granite core was laid bare it was carved by rivers and the waves of the sea into the majestic promontory we now see at Cape Woolamai. 




Explorer George Bass thought Cape Woolamai looked like a snapper’s head and named it Wollamai, an Aboriginal word for snapper.  Captain John Cleeland gave the same name to his homestead and his Melbourne Cup winning racehorse, although the spelling has changed over the years.The pink Woolamai granite is among the finest quality in the world and was quarried on the north shore of Cape Woolamai from 1891 for stone to face the Equitable Insurance Building on the corner of Collins and Elizabeth Street.  The pink granite can be seen as monuments and commemorative markers around Phillip Island and San Remo.


Cretaceous sandstones & mudstones 

In the Cretaceous Period, about 120 million years ago, when Dinosaurs ruledthe landand Australia was splitting and drifting away from Gondwana, the basement of Phillip Island was far from the sea.  Streams drained down from the hills into swampy areas depositing layers of mud and sand and in places quartz sand from the decomposing Woolamai granite.  Driftwood logs were compressed into chunks of fossil wood and coal between mudstones and gritty sandstones. 


This crumbly, yellow-brown and white rock seen from the lookout on the walking track above Rhyll Inlet was quarried for road material in the 1930s.  The ‘Diamond Dolly’ quarry provided employment for local farmers during the Depression but was soon abandoned as the rock contained too much clay from the mudstones. 


Eocene basalt & tuff 

In the Eocene, about 50 million years ago, molten rock burst out through great fiery craters all over the surface of what is now Phillip Island.  Volcanic lava spread across the land and ash blasted violently into the air. 


The eruptions continued for several million years and eventually built up the thick deposits of volcanic rock which make up most of the island.  On Round Island at the Nobbies there are six distinct lava flows piled one upon the other.  The black rock found around most of the island’s coastline is basalt (volcanic lava) and the red rock seen at places like Red Rocks is generally tuff (volcanic ash).




At Quoin Hill the volcanic crater has been quarried for bluestone since 1958.  The summit was originally 78 metres but is probably now less than 50 metres as the basalt rock is still being blasted and crushed for use in making roads and concrete.  The rock has been transformed into countless house slabs, footpaths and streets in housing estates on Phillip Island and throughout the district.


Sea level changes

After the volcanic period came to an end the landscape stabilised but then the surface was disrupted again, this time by earthquakes, some parts were raised while others subsided.Phillip Island and French island remained at a relatively high level, but the intervening areas, bounded by cracks known as faults, subsided to form the Western Port sunkland. 


Over geological time, sea level has changed dramatically.  The greenstones were formed when the base of what is now Phillip Island was under the sea.  The sandstones and mudstones from the Diamond Dolly quarry were formed when the land that is now Phillip Island was stranded far from the sea. 


During the Quaternary, the past two million years, the sea has sometimes been higher and at other times much lower than it is today.  During the last phase of cold climate, 80,000 to 18,000 years ago, the sea was at least 100 metres below its present level.  The land that is now Phillip Island was part of a wide coastal plain, linking Tasmania to the mainland. Aboriginal people came to Australia on the land bridge from New Guinea during this time.  They moved across the continent and made their way to Tasmania, some living on the land that is now Bass Strait. 


The sea rises and shapes the coast

As the climate warmed, the earth’s ice sheets melted flooding Western Port to form the present coastline and create Phillip Island, Churchill Island and French Island.  As the sea reached its present level, around 6,000 years ago, waves began to attack Phillip Island cutting back steep cliffs and shaping rocky platforms and coastal features such as Pyramid Rock, the Blowhole, the Colonnades and Forrest Caves.  These places have long been part of Phillip Island’s scenic attractions.  The rising sea brought sand from the sea floor to form Phillip Island’s beaches


Wind-blown sand built up to form the high dunes that now connect Cape Woolamai and the former Summerland Island to Phillip Island and cover the cliffs along the south coast.These dunes have become home to a million Short-tailed Shearwaters (muttonbirds) which fly here each year from the islands off Alaska to breed.


Over the centuries, mud washed by creeks and rivers into Western Port was carried by currents on to the eastern shore of the island, where it was deposited to form tidal mudflats on which seagrass meadows and mangrove-fringed salt marshes developed.Rhyll Inlet is now part of a Ramsar site internationally recognised for its importance to migratory wading birds from the northern hemisphere.  This is a great place for birdwatchers, especially in spring and summer.These muddy habitats are also important as fish nurseries and help to make Western Port Bay a popular fishing spot. 


Over the centuries, great volumes of sand also drifted across the entrances to former embayments, enclosing them from the sea as lagoons.  These shrunk to lakes and reedy marshes, creating new wetland habitats for plants and animals at McHaffie Lagoon, Flynn Lagoon, Green Lake and Swan Lake.


Boon Wurrung people are the first to come 

Generations of Boon Wurrung people would have adapted to these remarkable changes as the sea slowly rose to surround and create Phillip Island.   It is said the Boon Wurrung visited in spring and summer when food was plentiful and the water was calm for crossing. 


Middens containing the remains of shellfish, shearwaters and marsupials can be found behind beaches and in dunes around the island including at Forrest Caves, Cat Bay, Summerland dunes and at Swan Lake where waterfowl and shearwaters are plentiful.Stone artefacts have also been found.  The McHaffies found numerous chippings from stone implements near Cat Bay, indicating that this was a manufacturing site for the Boon Wurrung.


A midden at Point Grant dated at approximately 2,000 years contained various shells including limpets (85%) and abalone (5%). The bones of penguin, wallaby, possum and small amounts of seal and fish were also present.  Stone tools, mainly flint flakes, were found as well as charcoal and ochre.


The sealers arrive

George Bass is credited as the first European to see Phillip Island.  He arrived with his six-man crew in an open whale boat on 5th January 1798.  By 1801, gangs of sealers were harvesting seals at Seal Rocks and were soon living year round on the island in bark huts.  Louis Sainson, the artist aboard Dumont D’Urville’s 1826 French expedition, sketched a sealers hut on the bluff now known as Lady Nelson Point at Rhyll.   


The sealers took Boon Wurrung women for wives and to help clean the skins.  The local Boon Wurrung clan suffered greatly and their visits soon stopped completely. 


By 1860 the seal colony was virtually decimated and in 1891 seals were protected by law. 


Woodlands and scrub are cleared for farming and crops

In 1842, just seven years after Melbourne was founded, J.D. McHaffie leased the whole of Phillip Island.  At first fire was used to clear the woodlands and scrub.  One hundred years on, tractors and government incentives accelerated the pace of land clearing, radically changing the landscape.


Chicory farming began in 1870.  It was a popular coffee substitute before the days of instant coffee.  The root was harvested and dried in steep-roofed brick or concrete kilns.  Much of the Island’s remaining timber was used to fire the kilns.  It took three tons of wood to produce just one ton of dried chicory.  The last crop was dried in 1987. 




Holidays, hotels and housing estates 

Phillip Island has been a holiday destination since the early days of European settlement and was marketed as the “natural attraction” long before the term ‘ecotourism’ was first coined.In the 1840s, Melbourne’s social elite travelled by horse and buggy then boat across Western Port to visit the McHaffies.  Some went shooting hares, pheasants, partridges and quail that had been introduced by the acclimatisation society. 


From 1870 people stayed at the Isle of Wight Hotel and went boating on Green Lake.  Artists came to paint the landscape including Eugene von Guerard, Tom Roberts and Arthur Streeton.  Eugene von Guerard first visited in 1869 and his famous ‘View of granite rocks at Cape Woolamai’ was painted in 1872.  Naturalists came to observe nature, recording the plants, animals and landscape of late nineteenth and early twentieth century Phillip Island. 


In the 1920s A.K.T. Sambell’s Holiday Development Company built a jetty, a golf course and a guest house on the Summerland Peninsula near today’s Penguin Parade.The golf course is now the Penguin Parade car park and remains of the old jetty are still standing in Cat Bay.Charles Grayden Jnr. operated a tourist bus on the island in the 1920s taking visitors to the Nobbies and Summerlands.In 1928, Bert West led the first penguin viewing by torchlight.


In 1940 a bridge connected Phillip Island to the mainland.  In the 1950s, with easy access to the island, holiday houses started springing up at Surf Beach and Summerland Estate.  Through the 1960s, 70’s and 80s, housing estates stretched along the coast from Cape Woolamai to Smith’s Beach.  More and more people came to surf and swim at the beaches, go fishing in Western Port Bay, enjoy the coastal scenery and see the remarkable wildlife. 


Over the first century of European settlement, the island’s woodlands were replaced by farmland.In the decades that followed, housing development spread like wildfire across the landscape and people began to wonder what the island would look like in 30 or 50 years.


Keeping the nature of Phillip Island

Phillip Island has had a rocky history of people living and working closely with nature.Sealing almost decimated the seals in the 1800s but now Seal Rocks is home to 30,000 seals. 


Early farming practices so comprehensively cleared the land that soils became saline and stock had little shelter.  Since then, hundreds of thousands, perhaps millions of trees, shrubs and grasses have been planted on farms, foreshores and conservation reserves across the island.Much has been done to repair degraded landscapes, restore habitats and provide boardwalks and walking tracks to protect popular places from trampling feet while enabling people to enjoy this beautiful place. 


But perhaps one of the biggest threats to Phillip Island’s natural environment and rural landscape is being loved to death.  Three and a half million people visit this small island every year and houses still creep onto farmland to the east and west of Cowes. 


As the 150th anniversary of free settlement approaches, it is time to reflect upon the island’s outstanding natural, rural and scenic heritage.  It is time to consolidate future development in existing townships and keep the nature of Phillip Island for its wildlife and for generations of people to come.

Photos by Linda Cuttriss.



Vote of thanks:

John Eddy gave the vote of thanks, saying that the Geology chapter of Phillip Island in Picture and Story was his geology “Bible” as a young person. Linda had managed to make her information highly accessible, with beautiful photos to illustrate her points. She also connected everything we as humans do on Phillip Island with the geology and landscape.