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.

7 Replies to “Rocks at Wasson Bluff”

  1. What cool rocks, patterns and colours! Is “cool” a technical term in geology? I have been looking at many many rocks and their formations on the South West coast of Scotland while on holiday lately but while fascinated by the structures etc., I was frustrated at not knowing the geological reasoning behind them. Maybe I will post some of them in the next few weeks.

  2. Trying to understand what you are looking at with rocks and their formations is like unravelling a multidimensional puzzle in space and time. I have found that it is useful to find something about the geology of the general area first and then home in on information about the specific location. A good starting point for south west Scotland for example, if you have not come across it already, is the Scottish Natural Heritage and British Geological Society publication “Southwest Scotland: A Landscape Fashioned by Geology” which can be downloaded as a pdf file from http://www.snh.org.uk/pdfs/publications/geology/southwestscotland.pdf

  3. Thank you, Frogend_dweller. I am hoping that the effort will keep my little grey cells from diminishing. Learning geology with all its specialist terminology is like learning an exotic foreign language.

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