The Roar of the Bay

The Roar of the Bay
The Roar of the Bay

Tuesday, July 26, 2011

Wards Beach / Brookville Rock (Parrsboro, Nova Scotia)

This curative walk organized by the Fundy Geologica Museum of Parrsboro (Nova Scotia) took us about 15 minutes West of Parrsboro (on the other side of Dilligent River). Here's a resume from the FGM website:

View where continents have collided, crushing Coal Age sediments and older rocks between North America and Africa during the formation of Pangea. The cliffs along the shore contain evidence of folding and faulting, and mixing of rock types together within the fault zone.

- FGM Curative Walks

This excursion emphasizes on the coming together of continents and the processes that changed the structure of the rocks in the region.

Driving south in the early morning there was thick fog everywhere from Moncton all the way down the Fundy coast. This location is located about 15 minutes West of Parrsboro. To access the beach, you have to drive down a short dirt road called Wards Brook road. Arriving at the beach it lifted, making way to a very hot Sun. It wasn't too bad as there was a nice cool breeze from the coast. What struck me at first upon setting foot on the beach was the black, shiny sand. You'd move it around and it was black through and through. The local rock is made up of a dark, shiny slate, or shale that runs for miles. Another very amazing thing is that this region is just a few kilometers from Parrsboro and the geologoly and stratigraphy is so different. Where you get your red triassic sandstone and volcanic rock, here in the Brookville area its dark shale and slate with glacial till, igneous rocks, and minerals like rhyolite.

Fog lifting (notice the black rocky sand)

Heading East

Here the cliffs are made up of these folded strata of shiny shale, deposited gently over time, and then bent and rebent numerous times over a long period when the continents were being squeezed and pushed together. The layer of brown sediment on top is glacial till from glaciers that moved and grinded, eventually melting and depositing large deposits of till. The till contains rocks and sediments from other regions that eventually made their way here. The blackish shale dates at about the formation of the supercontinent Pangea, in this case about the 300-280 million mark smack in the Carboniferous (upper/lower) period. The glacial till is a lot more recent, possibly dating from the last ice age, less than 40,000 years ago.

Here the stratum is pushed like an accordeon. The folds are pushed one way to create the waves (horizontally) and then you have other forces pushing a different direction, causing this deformed waved pattern. This tug of war created all this pushing and slipping, producing the look that you get of these cliffs today.

In these black shiny cliffs you'll sometime find quartzite. Quartzite is a rock created by metamorphism (from one form to another) by extreme heat and pressure. Quartzite was sandstone, in this case sand that infiltrated in cavities, creating layers or different size of globes that end up like the boulder in the picture above.

Usually we would be able to see the banks on the opposite side, but the fog was still thick at that time. We could make out the sound of whales singing. Our tour guide Ken Adams says that you'd usually encounter seals on this beach, but today they were nowhere in sight.

Another example of folding

The end of our destination for that day. The orange colored rock formation is mostly rhyolite, and the cliffs on its right contain different rock types.

The cliffs are made up of different rock types from different periods. You can see there's a wedge like section of the cliffs that are made up of different rocks just by the different colors. There are sections along the fault in this region that are 'bubbles' showing up like this one where you'll get this type of diversity.

What I find amazing about the Maritimes is you can find yourself in a spot, drive into another location for a few minutes and encounter a whole different topography.

Till next time!

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