Old Harry Rocks, the Jurassic Coast

The Jurassic Scene tied up at Poole Quay - it takes trippers over to Swanage around the Jurassic Coast

In August 2010, on a drizzly day, we took a boat trip from Poole Quay to Swanage, around Old Harry Rocks on the Jurassic Coast of East Dorset.

We had already seen these chalk stacks in the distance from various points – from Brownsea Island, from Studland and even from Bournemouth. So they were a sight we wanted to view from a closer vantage point.

Old Harry Rocks can be seen from Brownsea Island, looking through the mouth of Poole Harbour, from Studland and even from Bournemouth

Old Harry Rocks can be seen from all over East Dorset - this is a view from Brownsea Island, snapped in 2009

Old Harry Rocks seen from Studland village - a picture taken in 2009

A distant view of Old Harry Rocks, seen from Bournemouth's beach in August 2010

A Harry Paye day is held every June on Poole Quay to celebrate the notorious pirate, who died in 1419...

Some say the Old Harry of the name is the devil, others believe it was named after the famous Poole pirate Harry Paye, who died in 1419.

Old Harry Rocks mark the eastern end of the Jurassic Coast UNESCO World Heritage Site. The cliffs have gradually eroded over the centuries, with new isolated stacks forming as the arches grow and breach into gaps. The small stump next to Old Harry himself (the end stack) used to be of equal stature and is known as Harry’s wife, but she crumbled in 1896.

The western end of the Jurassic Coast is at Orcombe Point near Exmouth in East Devon and from there to Old Harry the distance is 95 miles (153 kilometres).

On the way to Old Harry Rocks, a spit of Studland sand in the foreground

Vehicles at Studland awaiting the arrival of the chain ferry across the mouth of Poole Harbour to Sandbanks

The Poole side of Old Harry Rocks

The cliffs are made of limestone, with thin bands of flint. Some geologists believe they were originally joined up to the Needles, similar stacks off the Isle of Wight, and formed a range of hills until they were inundated at the end of the last Ice Age about 14,000 years ago.

Until the 1770s it was possible to walk all the way along from the headland of Handfast Point to Old Harry, before the rocks crumbled and the gaps formed.

A closer view of the stacks of Old Harry Rocks, seen from the Poole side

Rounding the bend of Old Harry Rocks

Old Harry Rocks from the Swanage side – the stretch in the middle is known as No Man’s Land and the gap between it and the headland of Handfast Point is called St Lucas' Leap

A yacht sails past the stacks of Old Harry Rocks

Old Harry Rocks - the tiny stump next to Old Harry himself used to be his wife, but the rock crumbled into the sea in 1896

The Jurassic Coast between Old Harry Rocks and Ballard Point

Although it’s called the Jurassic Coast, it consists of Triassic, Jurassic and Cretaceous cliffs, spanning the Mesozoic Era, documenting 180 million years of geological history.

The stretch of chalk between Old Harry and Swanage, around Ballard Point, formed towards the very end of the Cretaceous period, over 65 million years ago.

Chalk is almost pure limestone (calcium carbonate), made from trillions of microscopic skeletons and shells from plankton which fell to the seabed in the warm waters of the time and formed characteristic horizontal strata or layers.

The chalk also contains fossils of larger creatures such as ammonites, gastropods, sea urchins, sponges and bivalve sea shells.

Sponges and a type of plankton called radiolaria used silica instead of calcium carbonate to form their skeletons and when they died their remains formed nodules of hard, black flint, a glassy material which appears in bands as a distinctive feature of the chalk cliffs.

At the end of Ballard’s Point the strata have been tilted by upheavals to become vertical.

The Jurassic Coast between Old Harry Rocks and Ballard Point - look at those diagonal strata of the Ballard Fault...

Ballard Point with its vertical strata

Ballard Down leading to Ballard Point - looked a bit slippery on top...

Going around Ballard Point on the Jurassic Coast

Approaching Swanage on the Jurassic Scene on a drizzly day in August 2010

Swanage pier

Alongside Swanage pier before the return trip to Poole

The Jurassic Coast - Ballard Down with tiny people on top to demonstrate the scale of the cliffs

Old Harry Rocks on the way back from Swanage

Going around Old Harry Rocks from the Swanage side

A yacht sails past the cliffs of the Jurassic Coast

A sheltered corner of the Jurassic Scene

The Poole harbour pilot boat escorting a cargo ship out to sea

The Poole harbour pilot boat returns to port past the chain ferry on Sandbanks

The Scot Explorer heading into Poole Harbour, with a Condor ferry to the right

The Scot Explorer was bringing in a cargo of timber - one pallet had Cardiff written on it...

Cargo vessels in Poole Docks - many leave with gravel or china clay from the stone of the Isle of Purbeck, the peninsula to the south of Poole

A Condor ferry in port in Poole - it travels to the Channel Islands

Some useful links:
The Jurassic Coast official website
The Jurassic Coast on Wikipedia
The geology of Old Harry and Ballard Point in detail
The website for Blue Line Cruises around Old Harry Rocks