About winderjssc

Jessica Winder has a background in ecological studies in both the museum and the research laboratory. She is passionate about the natural world right on our doorsteps. She is enthusiastic about capturing what she sees through photography and wants to open the eyes of everyone to the beauty and fascination of nature. She is author of 'Jessica's Nature Blog' at https://natureinfocus.wordpress.com. Jessica has also extensively researched macroscopic variations in oyster and other edible marine mollusc shells from archaeological excavations as a means of understanding past exploitation of marine shellfish resources. She is an archaeo-malacological consultant through Oysters etc. and is publishing summaries of her shell research work on the WordPress Blog called 'Oysters etc.' at http://oystersetcetera.wordpress.com 'Photographic Salmagundi' at http://photosalmagundi.wordpress.com is a showcase of photographs and digital art on all sorts of subjects - not just natural history.

Rocks at Wasson Bluff

Wasson Bluff is famous. A site with an international reputation. It is located to the east of Parrsboro on the northern shore of the Minas Basin in Nova Scotia, Canada, and is best known for its fossils and its fascinating geology. Canada’s oldest dinosaur skeletons are being excavated in earliest Jurassic sedimentary rocks at Wasson Bluff Palaeontological Protected Site. Within these rocks an important vertebrate fauna including jaw bones and skulls of a rare protomammal, Pachygenelus were discovered, and also bones and scales of the lizard-like reptile Clevosaurus, a crocodile-like reptile Protosuchus, fish scales and prosauropod dinosaurs (Donohoe et al. 2005).

The bluff consists of complexly faulted and tilted sedimentary rocks and basalt. Most of the rocks of the Bluff itself are composed of brownish Jurassic North Mountain Basalt with evidence of hexagonal cooling joints. Much of it is brecciated. The basalt boulders that have fallen to the beach include many with pockets and streaks of various minerals; the green deposits seen in the photographs of boulders on the beach may be the mineral celadonite. A fault brings the mostly brecciated basalt into contact with The Triassic Partridge Island Member of the Upper Blomidon Formation. The Blomidon Formation rock is described as well-bedded grey, red and purple sandstone and mudstone with the Partridge Island Member of it being conglomeritic but fining upwards to siltstone but beneath the basalt. This junction of rock types can be seen in images 1 and 17 in the gallery of photographs above this text and image 25 in the gallery below.

Carboniferous Parrsboro Formation “red bed” strata are exposed for a short distance to the east of the bluff and on the east of the small stream that traverses a narrow, steep sided, tree-lined valley before it crosses the beach.

Further east along the beach, the soft red Jurassic period McCoy Brook Formation rocks which originated as sediments associated with rivers, lakes, and wind-blown sand dunes form a low crumbling cliff and can be seen in the photographs as the brighter red rocks often with white stripes and patches.

The local Fundy Geological Museum conducts tours of the site and works with academics on fossil excavations at the site every summer.

Please note that all the identifications attached to the photographs of the rocks are tentative and subject to verification – I am just an interested natural historian and not a professional geologist.

REFERENCES

Donohoe, H.V.Jr., White, C.E., Raeside. R.P., and Fisher, B.E. 2005. Geological Highway Map of Nova Scotia, Third Edition. Atlantic Geoscience Society Special Publications #1.

Nova Scotia Field Guide, Arthur D. Storke Memorial Expedition, Department of Earth and Environmental Sciences, Columbia University in the State of New York, August 23 to September 2, 2012.

A Walk at Rocquaine Bay

Follow in my footsteps with a virtual walk along beautiful Rocquaine Bay on the west coast of the Channel Island of Guernsey. It is protected by a long sea defence wall which has employed different construction techniques along its length; mostly using local stone but also with along stretch of reinforced concrete (probably originating from German occupation World War II fortifications). The beach is both rocky and sandy with some pebble patches. Seaweeds of every colour abound. Huge limpets with white shells cluster on the bright orange-spattered L’Eree granite bedrock while outcrops of monochrome microgranodiorite occur on the upper shore near Fort Grey. Marine worm casts cover the softer muddy sands. Streams flow across the shore, their clear shallow water reflecting sunlight from the ripple crests and creating shadow patterns. A small stone jetty looks marooned among the rocks and a multi-coloured carpet of weed. Small boats bobbing in the turquoise water, rusty buoys and chains half-buried in seaweed, and algae-encrusted mooring ropes add to the evidence for fishing and leisure boating activities.

Click on the first picture to view the images in the gallery in the sequence that they were taken during the walk.

A Vogesite Dyke at L’Eree

Detail of a vogesite dyke at L'Eree in the Channel Island of Guernsey

Dykes formed when molten lava flowed into deep cracks and fissures in pre-existing rocks millennia ago. The lava set in a sheet form within the other rock but frequently dykes are seen on the surface today, after many years of erosion and earth movements, as lines of contrasting rock type. Dykes are composed of many different mineral combinations. When I visited Guernsey in the Channel Islands last year I discovered three types of dyke cutting through the predominantly igneous and metamorphosed rocks. I have already shown some pictures of dolerite, albite dolerite, and lamprophyre dykes, all of which seem to be quite common on the island. However, on an expedition to L’Eree on the north-west coast I spotted a dyke with a very different texture cutting east-west across the other  north-south dykes. This proved to be a vogesite dyke.

Vogesite has a very characteristic texture made up of rounded mineral inclusions – ‘large euhedral amphibole phenocrysts’  – set in a fine grained groundmass of plagioclase feldspar, alkali feldspar and quartz (Roach et al. 1991).

REFERENCES

British Geological Survey Classical areas of British geology: Guernsey, Channel Islands Sheet, 1 (Solid and Drift) Scale 1:25,000. NERC, Crown Copyright 1986.

De Pomerai, M. and Robinson A. 1994 The Rocks and Scenery of Guernsey, illustrated by Nicola Tomlins, Guernsey: La Société Guernsaise, ISBN 0 9518075 2 8, 30-34.

Roach, R. A., Topley, C. G., Brown, M., Bland, A. M. and D’Lemos, R. S. 1991. Outline and Guide to the Geology of Guernsey, Itinerary 9 – Jerbourg Peninsula, 76. Guernsey Museum Monograph No. 3, Gloucestershire: Alan Sutton Publishing. ISBN 1 871560 02 0, p 22.

Changes with the seasons – The Stile

Rural view with stile in summer on the Cerne Valley Trail, Dorset, England.

I’ve been recording the changes that come with season and weather as I walk along the Cerne Valley Trail in Dorset, England. The horse chestnut tree by the stile in these photographs is a convenient marker to illustrate the transition from bare branches of winter to full foliage in summer. Already, by September, the leaves are turning brown getting ready to fall. It is not only the tree that shows the changes but the ground cover vegetation, and the crops in the fields.

Parrsboro Shore

Beachscape with lighthouse at Parrsboro, Nova Scotia, Canada.

Views of the Parrsboro shore and harbour at low tide one evening in May 2016. We stopped off there to have a seafood supper at the Harbour View Restaurant. The tidal rise and fall on this beach can be as much as 45 feet and the sea goes way out. Boats moored in the harbour are stranded on the mud at low tide. The small town of Parrsboro lying a little further inland and up river of the shore is where we based ourselves to explore the area. We stayed at the Parrsboro Mansion Inn from which we travelled out to Joggins Fossil Cliffs, Cap D’Or, Spencer’s Island, Clarke Head, and Wasson Bluff. On a previous visit to the area in 2014 we visited the Fundy Geological Museum, Partridge Island, and Joggins.

Beachscape with moored boat at Parrsboro, Nova Scotia, Canada.

Beachscape with lighthouse at Parrsboro, Nova Scotia, Canada.

Beachscape with red cliffs at Parrsboro, Nova Scotia, Canada.

Beachscape with evening light reflected on mud at Parrsboro, Nova Scotia, Canada.

Beachscape with lighthouse at Parrsboro, Nova Scotia, Canada.

Beachscape with low tide standing water pools at Parrsboro, Nova Scotia, Canada.