09.03.10 - Rocks on new stamps
Rocks that make up the Island feature on a new set of postage stamps released by Jersey Post under the title of Petrology.
Petrology is the branch of geology that studies rocks, and the conditions in which rocks form. The stamp issue is dedicated to this discipline and follows on from the Mineralogy stamps issued in 2007 which depicted various mineral specimens discovered in Jersey and its offshore reefs.
The rocks illustrated on the Petrology stamps are on display at the geology museum at La Hougue Bie and were painted by UK artist Jennifer Toombs who has been working with Jersey Post since 1970. Petrology is her 26th commission. Other issues painted by her include Mineralogy, Viking Heritage and Dr Lilian Grandin who was Jersey’s first female doctor. The Curator of Archaeology at Jersey Heritage, Olga Finch, assisted Jersey Post in the research for this stamp issue.
One of the rocks featured is Rozel Conglomerate which is found in the north-east of the Island. It is a sedimentary rock composed of rounded fragments of granite, shale, rhyolite and andesite cemented together.
Ms Finch said: ‘Rozel Conglomerates are the youngest rock formation in the Island, having been formed about 400 million years ago. The oldest rocks are the shales - which are more than 700 million years old - and they were formed by muddy currents flowing down a sloping seabed which deposited layer after layer of fine sand and clay which, over time, were compressed and cemented into shales. The best known rocks in Jersey are the pink and grey granites and diorites which make up a third of the Island and were formed between 560 and 480 million years ago by molten rock cooling and solidifying deep between the Earth’s surface.’
The Presentation Pack shows shale from L’Ouzière in St Ouen while the First Day Cover envelope features conglomerate and shale found at Tête des Hougues in Trinity.
The other rocks and rock formation featured are: pegmatite found at Ronez, St John, diorite from Grève D’Azette, granite from Mont Mado, St John and andesite - a volcanic rock - which occurs on the north and south coast and in the centre of the Island.