Dolerite Polygons
Grant Dixon
Dolerite is an igneous rock that is unusually widespread in Tasmania and so significantly shapes the landscape. It has been described as ‘the rock that makes Tasmania’. During the breakup of Gondwana, dolerite magma intruded into the crust as subsurface dykes and sills (sheets). As the magma cooled and crystallised, regular vertical cracks propagated through the sills, forming polygonal columns. The characteristic form of many dolerite cliff-lines is due to this. Less common is such a clear exposure of a cross-section of these columns seen here, forming a glaciated pavement on the Ben Lomond plateau, their outline highlighted by a light fall of snow.
BEAKER STREET SCIENCE PHOTOGRAPHY PRIZE
This photograph was a finalist in Beaker Street’s annual Science Photography Prize. This highly-respected prize invites amateur and professional photographers to showcase the wonders of our extraordinary part of the world — which is teeming with science and scientists. Finalist images are displayed at the Tasmanian Museum and Art Gallery during Beaker Street Festival each August, with great prizes on offer for Judges’ and People’s Choice winners.
The Beaker Street Science Photography Prize is sponsored by Pennicott Foundation — thank you crew! It would not be possible without the support of Full Gamut, Tasmania’s premier fine art printers, as well as the wonderful Tasmanian businesses who donate prizes.
