clarence valley

CLARENCE STUDY

Watercolour on paper,
40cm x 30cm

The three red floral shapes represent the three volcanic shield centres of The Scenic Rim (Main Range, Focal Peak and Mount Warning).
The Clarence River once flowed north west into the Condamine River. However, today it flows south east down the western margin of the Clarence Morton Basin, against the folded and fractured rocks of the New England Fold Belt. It then takes a right angle bend at Grafton and flows northeast to Yamba on the New South Wales coast.

ONCE ONLY

Acrylic on canvas,
149cm x 89cm

The lower Clarence River today has very few large lakes associated with it. Sand, silt and clay have filled in much of the big, old lake that existed 6,000 years ago.

The reason the Clarence flows north-eastwards from Grafton is probably because its passage eastwards is blocked by the remnants of the old Tasman Mountain Range. These remnants can be seen at Brooms Head.

TELL TALE PEBBLES

Acrylic on canvas,
55cm x 44cm

The grey, areas at the top left are ancient marine sediments that were intruded with hot, granite magma around 250 million years ago (red, orange and yellow areas).

Geological evidence suggests that from around 220 to 100 million years ago the Clarence River flowed north westwards into the Condamine and on into a central, Australian, inland sea. The brown areas are rocks deposited when the Clarence River flowed north west into the Condamine. All this happened before there was a Tasman Sea.

The “green” areas on the “mauve, wriggly line” (the Condamine/Clarence watershed) are pebble remnants of the old north-westward flowing river system.

The current, north-east flowing, tributaries on the western side of the Clarence give clues to the original westward flow.

6,000 YEARS BEFORE PRESENT

Acrylic on canvas,
55cm x 44cm

Six thousand years ago the Clarence emptied into a giant lake system that stretched from Grafton to just west of Yamba. Remnants of the old, folded, Tasman Mountain Range can be seen in the bottom right. Immediately left of these are the talus, scree and fan deposits. Left again are the first river channels out of the mountains. The green represents the flood plains of the pre-historic Clarence River when it flowed “backwards” into the central inland sea, the “Eromanga”. The purple areas represent the lagoons in the flood plains that filled with plant material and later formed coal.

CENTRED

Acrylic on canvas,
55cm x 44cm

Following the formation of the Tasman Mountain Range it is thought that the primitive Clarence Valley was forming in the arm of a giant mega-fold, known as the Coffs Harbour Orocline. This would suggest that the birthplace of the Clarence River now lies somewhere out in the middle of the Tasman Sea.
At 220 million years to around 100 million years ago it seems the Clarence River ran north westwards into central Australia. Australia was on its side during this time and so the east coast of today was the south coast during this time. Hence the primitive Clarence River is depicted as running from bottom to top (south to North).

ART AND GEOLOGY ON THE CLARENCE

Sharing geoart and geostories in the outdoors with a TV camera makes for new approaches and challenging logistics. The mix of art, rocks, history and geography makes for a heady and exhilarating experience. Each story develops its own character and never stops evolving.