St. Mary Lake

This will be my last entry from our August excursion to the Gulf Islands. The next post will take us to a very different place.

Every year for twenty years we've been coming back to this beach. Maybe not just for the beach, but to the beach. I posted a more thorough description two years ago:
St. Mary Lake: August 2015

It hasn't changed too much in the last twenty years - geomorphologically. What has changed is the demographics - the little children have grown up and gone off to college and rarely make it back. The parents get older. Old folks stop coming. Younger families take their place.

The beach toys get larger and more interesting.

AERIAL VIEW

The swash zone doesn't shift much on this beach over the summer. Afternoon waves from the south try to smooth out whatever perturbations to the small pocket beach have been created with plastic shovels and buckets in the previous 24 hours. Fine sand, coarse sand, and small gravel sort and resort themselves just as on larger, more energetic beaches.

Beach toys left in shallow water influence wave patterns and sometimes leave strange little promontories, even after the temporary breakwater has been removed. 

Without a little new sand now and then and a summertime of human trampling, this little artificial beach would probably revert pretty quickly to reeds. There are too few waves and not enough sediment for beaches to form on their own.

Jackson Rock

Fulford Harbor, like pretty much everything else on Saltspring Island, is oriented NW-SE, reflecting the underlying geologic structure of the islands sedimentary rocks. Last week, during our annual trip to the island, I paddled from the head of the harbor out to Wen,Na,Nec (August 2013) and Jackson Rock, then back on the other side.

AERIAL VIEW

The northeast side of the harbor (the Fulford/Reginald Hill side) is steep and rocky and there are few beaches. The southwest side (from Drummond Park out toward Isabella Point) is a little more gradual and includes both more erodible glacial? sediments and a stream mouth or two, so the beaches are a little better developed.

Here on Jackson Rock, the only material available to build the tiny beaches is broken shell. And the orientation of the beaches and bars is a messy function of the islets' irregular configuration and bathymetry.

Quarry Beach

Tafoni weathering in sandstone

There can't be many publicly accessible beaches on Salt Spring that I haven't visited at this point, but each year I try to find something new. And fortunately, I think people on the island have done a pretty good job of generating new access points to keep me amused.

This is what most folks would probably call a rocky beach. It's not far from Vesuvius Bay (August 2013), where the geology is similar, but where at least there's a small cove to trap a nice little beach. Here, there's just not much beach, which makes it easier to admire the steeply tilted sedimentary layers of the Nanaimo Formation.

AERIAL VIEW

Could almost be a Seahawk

Yeo Point

Yeo Point itself is not a beach, but a rocky promontory at the north end of Ruckle Park on the southeastern corner of Saltspring Island. But it shelters a small, gravelly pocket beach on its south side. Nothing remarkable, but wonderfully quiet and secluded early on a weekday morning. More photos at hshipman.
AERIAL VIEW

On the north side of the point, there is an even smaller beach - probably not a beach at all by normal folks' standards. It's basically an accumulation of sand and gravel-size shell fragments (it's the only sediment available) pushed up onto the rocky ledges.

St Mary Lake

This relatively small lake on Saltspring Island has neither the waves nor the sediment to form natural beaches and is fringed by reeds everywhere except where the bedrock plunges too steeply to provide any shallow water where vegetation can take hold. And like most lakes in the great northwest, the original shoreline was probably once a tangle of fallen trees.

This beach is artificial, probably created many decades ago by cutting the vegetation, building two small rock groins, and dumping a few truckloads of coarse sand. I suppose they may have added a little sediment since, but in the 18 years I've been visiting it, I've seen very little change. 

AERIAL VIEW

Like all pocket beaches, it is swash-aligned, facing the dominant wind waves coming up the lake (corresponding to the maximum fetch). There's not a lot of action on this beach. There are no tides, although there is some seasonal fluctuation in the lake level. On windy days, waves can create small (tiny) berms, but mainly they just leave a line of froth. The only significant morphological change is the result of junior engineers building boat basins and sand castles.

I thought I'd added this beach to my collection years ago, but apparently this is its first appearance in this blog.  Ironic, given I've probably spent more time contemplating this beach than any other. It does show up regularly every August in my hshipman blog (here are posts from 2010, 2011, and 2012).

Chocolate Beach

The Chain Islands run in a line out of Ganges Harbor and make a great island hopping kayak tour. All are rocky and there is neither sediment nor opportunity for beaches to form. With this notable exception. Here on Third Sister Island, shell debris has found a place to accumulate and it has formed a wonderful white beach consisting almost entirely of broken shell fragments.

From a distance, I expected it to be a tombolo, but it is actually just a low rocky area where a beach has been able to form on one side. If the process that formed it is still active, which I expect it would be, then this beach is fairly young. Otherwise I would expect the shell debris to continue to accumulate and to wash over and cover the rocky backshore. I was surprised it hadn't. I wonder if the perfect storm could actually clear the shell completely off this beach, requiring time to rebuild.

Mark and I did it on our own, but this beach is the destination for guided half-day kayak trips out of Ganges and maybe it's called Chocolate Beach because it's where the chocolate bars come out of the dry bags. I was curious about how these daily visits affect the beach itself? One of the lessons of Cama Beach was that without people, the berm consists of largely intact clam shell, especially after a big storm. Once you let people back in, it is all rapidly turned to crushed shell.

AERIAL VIEW (Google Maps)

Wen,Na,Nec

I like that every time I come to Salt Spring, I find one or two new beaches. This one was unexpected and a new favorite. It's actually a couple of beaches along the exposed rocky shoreline at the south end of the island. The easternmost beach is a extremely well-sorted gravel pocket beach. The western beach is more complicated and is actually a small tombolo with fringing pocket beaches on each side.


These small beaches lie on land of the Tsawout First Nation and I really appreciated that they have allowed it to remain accessible. Hiswke - thank you! My apologies that my font options don't allow me all the proper accents/characters on the name of this site. This felt like a very special spot. And clearly, it had been special to many, many people before me, as witnessed by the anthropogenic stratigraphy of the exposed banks.

AERIAL VIEW (Google Maps)

The trees hanging over the rocky cliffs included both Madrone (Arbutus here in Canada) and Garry Oaks, which are fairly common in the Gulf Islands.

Price Road

Many small beaches on Salt Spring are swash-aligned pockets, completely contained by bedrock points.  Beddis Beach (Gravel Beach 2008), a short distance south of this one, is a great nearby example. 

This one off Price Road is not a pocket beach. The shoreline orientation changes and the beach becomes a little more swash-aligned, which allows a wider beach to build, but there's nothing at the distal end to keep it from spilling around the corner.  A small stream delta acts like a groin, and there's a small rock groin, too, but these simply the slow the beach down, they don't stop it.

The sediment on this beach appears to come from the shoreline to the south - eroding banks and a small stream mouth.

Farther downdrift the beach is coarse and narrow, except where a couple of groins attempt to trap the rapidly moving finer material. Half a mile farther north, where the coastline turns west again, the beach itself just keeps going strait, forming a small spit (a site for a paddle trip in a future year).

AERIAL VIEW (Google Maps)

I think one lesson here is that in this highly oblique wave environment (the west shore of Ganges Harbor), the width of the beach (the volume of the beach) is a function of the speed with which sediment passes through - which in turn is a function of the orientation of the beach.

Walker Hook

The northeast shore of Salt Spring Island is a relatively strait, steep, rocky edge along Trincomali Channel. Sediment sources are limited and wave action is highly oblique, so beaches are few and consist largely of narrow lenses of sand and gravel held by ledges of bedrock (Fernwood 2009) or associated with small stream deltas.

AERIAL VIEW (Google Maps)

But Walker Hook is a small rocky islet that lies just offshore and a tombolo has formed between it and the main island. The result is swash-aligned barrier facing into the southern waves with a protected embayment on its north side.

The island is public. The tombolo is not. So I paddled around from the public road end on the bay and landed discretely at each end of the beach to stretch my legs and take some pictures.

The beach is relatively sandy. Annuals were growing in the berm. Algae had washed up on the upper intertidal. And some sort of burrowing critters had left the mid-beach looking like it had goose bumps.

Like south-facing beaches anywhere on the Salish Sea, this one collects logs, but here someone has come along and stacked them like shingles. The backshore is high, suggesting it was filled in the past, and the imbricated logs act as a bulkhead.