The Roar of the Bay

The Roar of the Bay
The Roar of the Bay

Friday, June 15, 2012

Arisaig (Arasaig), Nova Scotia

Oh Arisaig, how I've longed to go visit ye!

I've been wanting to go visit Arisaig Provincial Park when I first compiled a list of sites to visit in Nova Scotia. Arisaig is on top of that list due to the importance of the fossils found there. It is said that the Silurian age rock outcrops in the Arisaig area are one of the best in the world. They give a good picture and interpretation into the paleoenvironment of that period.

Environment during the Silurian Period (~443 to 417 million years ago)

The Silurian Period that mostly saw life in water, from about 443 to 417 million years ago. Life stuck in the ocean and other bodies of water, as the surface was not inviting. Only a few tiny plants started to make the surface their home.

The environment in the seas and oceans of the Silurian would have been seen a diverse and abundant in animals such as early fish, trilobites, snails, molluscs (bivalves, brachiopods), crinoids (sea lilies), nautiloids, and many other genera. Most of these animals would have lived at the bottom of the sea floor or burrowing in the sand or silt. Some would have crawled and left traces, while others swam. The rich deposits of fossils at Arisaig give us a picture of a paleoenvironment that was abundant in the necessities of life for these organisms: food, oxygen, and sunlight. Sedimentary structures such as sand waves can be found, meaning that this type of environment would have been an open continental shelf with low water depths. Turbulent weather, like storms, would have helped shape the sea floor.

(illustration taken from brochure, NS Museum of Natural History)

You can click on this link < here > to find out more about the different species that made these seas their home.


Arisaig is a ways away from Moncton, about 270 kilometers. Which can take anywhere between 3 and 3.5 hours to reach, depending on which road you take. You could take the TransCanada highway 104 from Amherst to Truro, then continuing on to Stellarton and up the 345 to Arisaig, but that's boring drive. I opted instead to take the coastal road from Amherst to Tatamagouche, then onward to New Glasgow to get to Arisaig. It took me about 3.5 hours of driving time to get there, but well worth the drive!

Windsor Salt Mine (Pugwash, Nova Scotia)

After a few short stops along the way, and a few minor detours, I managed to reach Arisaig Provincial Park. The park is located before the wharf at Arisaig Point, coming from New Glasgow way. You can either park at the entrance or drive further in to the other parking lot.

Trails are nice and maintained

Trails going down to the beach

Before going down the beach, you can stop at the picnic tables under the covered hut. They installed some neat interpretive panels with information on Arisaig's paleoenvironment and geography.


Map of the park

Visual interpretation of Arisaig's environment during the Silurian

After the picnic tables, you can take the trail down to the shore. The trails split in two places, both with access to the beach. The trail East was a bit tricky to go down as the steps going down were not there due to construction. It wasn't too far down so I managed to make my way safely.

View of the West steps from the East steps

The scenery is pretty cool once you hit the sand. When you face the ocean, on the right you see this:


.. and when you look on your left, you see this:


The fossil bearing cliffs are along the West side of the park, towards McAras Brook. On the East side towards Arisaig Point, the topography changes and you get rhyolitic and basaltic rocks from the Ordovician period, mostly devoid of fossils. I didn't get the chance to check those cliffs as they might be bearing minerals, but I'll make it an item on my 'to do' list next time I come visit.

Exposed outcrop of mudstone and siltstone (Arisaig Group)

The cliffs where I was standing at, and all the way to the wharf, are poor in fossils, if any. You need to walk a couple of meters before reaching the fossil deposits. The layers are tilted at about 25 degrees, but vary along the 5 kilometer stretch West. The zone closest to the wharf show signs of work with folds and other features. You can also see the presence left by the last great iceflows from the last ice age, that disappeared about 10,000 years ago. That period of upheaval and receeding ice deposited glacial till, seen at the top of the cliffs.

Tilted layers of siltstone and mudstone

Distinct layer of glacial till (top)

After a few minutes of walking I get to my first fossil bearing outcrop. The cliffs are a mix of alternating strata of undulatory sandstone and siltstone/mudstone. The outcrops stretch to the floor for a few meters at some places. The sandstone seem to interpret a calmer environment than the other type of sedimentary layers.


It was tough for me to find the fossils at first. I wasn't sure how to check or how to approach and find anything. I took some time to eyeball some layers and in no time I found my first brachiopod.

First!

Brachiopods are a little different than normal clams (bivalves). They have two shells, but they're not of the same shape. From what I've seen, they're the most common found here in Arisaig.


The examples that you get are very nice indeed, but keeping them together can be a bit challenging as silt can easily break apart in your hands if you're not careful. Extra care should be taken when handling these.




The next few photos are what you mostly see from the outcrops jutting out from the cliffs, when you make your way towards McAras Brook. You can see the alternating layers of sediments, the kinks and breaks in the cliffs due to tectonic activity at one time or another, and the layering of different depositional sediments influenced by current environmental events.





Fossil bearing sandstone



At this point, the fossils just kept on popping from everywhere. I was surprised at how detailed and well preserved these fossils were in this kind of exposure. Other types of fossils would show up, such as graptolites, crinoids (stem), nautiloids, and fish remains (small bones, scales).



The sandstone layers are also fossil rich. Details vary depending on the layer you're looking at. In the picture above, the fossils are located where the photo scale is.


I was there for only a few hours, but for the short time I spent it was well worth the drive to Arisaig. That corner of Nova Scotia is just amazing. I know that if I'd spent more time scratching and sniffing around, I'd find trace fossils or trilobite bits.

I hope to be able to head out again later this year. The next time I swing that way, I'll venture North on the other side of Arisaig Point where the topography changes to volcanic rock, some of the oldest rocks in the area. We'll have to see about that.

Tuesday, June 12, 2012

In Alma, All I See Is Red

I had the Friday off (May 18th) before the long weekend of May. It sucked that I had to work the long weekend, but knew that I'd have plenty of time off coming up. So being stuck at work during the nice, long weekend wasn't too bad to bare. I wasn't planning to do too much that day, so I moped around the house for a bit. I was getting bored out of my mind and needed to get out of the house, so I decided to hop in my car at around 2pm and go for a drive. At first I didn't plan to go too far, but I found myself driving from Riverview towards Hillsborough.

By the time I stopped driving, I was pulling in the Fundy Park Info Center parking lot. I said to myself, might as well go in and check the boutique. Bought a few goodies and went back in town.


I decided to stop at the Tides Restaurant in Alma for an early supper. They usually open for the season during the long weekend, but ended up opening early for Mother's Day. I can say that the food here is freakin good and the view is awesome. Depending on the tide, you can see the boats move around at high tide, or people walking at low tide on the beach where those same boats would have been.


I always go for the herbed chicken. So good! The restaurant also has an outdoor patio where the menu is a little different. I had room for dessert, so I asked if they had anything new on their menu. The waitress mentioned a new vanilla and salty caramel cake. I jumped on the occasion and let me tell you, that cake didn't last long on my plate. The chocolate desserts she had showed me earlier looked good, but man that cake topped it. Didn't even have the time to take a photo of it, it was already long gone!

I looked at my watch and it wasn't 5pm yet, and we were smack in the middle of low tide. Since it was so nice out, I drove my car and parked at the old rink, and walked down the path by the Alma fishmarket and to the beach.


I've been here before but haven't walked real far. The sand stone in this area is mostly medium size grain to coarse, buff colored, and full of plant material. There are numerous layers of bio-rich plant bearing mudstone, and a shit load of channel bodies.

Dark, greyish band is rich in biomass

The buff colored sandstone is littered with plants (orange)

Channels, different deposition

Calamites (left extremity bending down and tapered)


Minor fault (?), minor displacement

Big arse channel, with alternating depositional sediments

I didn't bring my normal tools with me or my camera, so I took those pics with my blackberry phone, which was about to croak on me. I was taking pics and checking the sandstone at my feet when I noticed this on the horizon:


The foreground shows the typical buff colored sandstone cliffs you'd see from Alma to this location (albeit hard to see in this picture is the incline change of the strata). In the background, you get these purple-reddish cliffs, with another smaller section that's popping a shade redder. I WAS gonna turn around and head back to town, but when I saw that, that peeked my interest. I knew that from the other side near Dennis Beach near Cape Enrage you'd get red Triassic sandstone and/or conglomerates (quartzite), but from reading New Brunswick topo maps and actually being on site, something just doesn't jive.

Red arrow indicates area of interest
('bout 1.4Km from Alma)
N 45 36' 21.31
W 64 54' 43.59


From the coordinates I've indicated above, the split (middle right of photo) seperates two formations that couldn't be more topographically different. For this blog's purposes, I'll call it a fault (Major? I know there's the Harvey-Hopewell Fault that strikes and dips at a different direction) for the sake of being different, right? The base of the 'fault' lies a talus pile, a somewhat heap of rock. On the left side (using the picture as orientation) of the talus pile are layers (or strata) of red to dark brown sandstone that strike at a different angle than the buff or tan colored sandstone from the ones West of this spot. The sandstone contains from what I could tell at the time paleosol, with distinct features on the surface of the stratum. This red sandstone here only forms a tight, small triangular wedge between the purple-reddish rock on the right of the 'fault', and the buff 'Boss Point' buff to tan sandstone on the left. If you walk a couple of hundred feet West from that spot, you'll notice that the layers of sandstone are flipped to an almost vertical position and very distorted. These sandstone also contain plant rich grey mudstones several feet in thickness.

On the right of the talus pile, including this heap of loose stuff, is this purple-red metamorphic looking stuff. At quick glance it looked like rhyolitic metamorphic stuff. Second pair of eyes that looked at my samples I brought from this area suggested a more hetatite-ish composition. To add to this is that this stuff is what makes up these cliffs from here to way further East. I didn't venture further than Owl's Head, but I can tell you that the cliffs here are of the same stuff. I'm sure I'd find the same red sandstone from when first encountered, but I'd have to come back to walk all the way to Red Head, past Dennis Beach. I'm very familiar with Waterside Beach as I've done some recent work for my friend Matt, but not at all with Dennis Beach.

Ss - Sandstone I'm familiar with in the area. Selected in red are areas of future study


One of several waterfalls


At this point my Blackberry was dying on me. I managed to take a few more pics before it ran out of juice. The left portion of the picture above shows the buff sanstone, seen here as distorted and gnarled. The middle section is the red sandstone with distinctive layers. The right is the purple-reddish metamorphic looking stuff that make most of the neighboring cliffs seen in the immediate area East of this position.

Close-up of the red sandstone, showing different physical features
(last pic my phone took before kicking the bucket)


I've brought a few samples with me to have a closer look at them. The samples contained different type of minerals and possibly metals. Some of the pieces were quite heavy, some heavier than they looked.


I'm planning to go back very soon. I've got some vacation coming up and if weather permits, I'll be heading back down there for the day to get a better look, bring my tools, and my freakin' camera. My plan is to reach the other side of Owl's Head and see how far we get this type of rock, or even how they package up. I hope to be able to made some crude topo mapping of the area and jut up something to be able to play with after. I'm not convinced that what we see on the maps are what we're seeing on the field. We'll have to find out then, yeah?

Till next time!