Harling Point, The Harpoon Erratic, and Migmatite Bedrock
Post submitted by Bud Hardwick, Bellingham; additional geology by Dave Tucker
Harling Point protrudes into the Strait of Juan de Fuca at the southeastern tip of Vancouver Island. It is located in the municipality of Oak Bay, immediately east of Victoria. The shoreline geology provides easy access to the mixed igneous and metamorphic rocks known as migmatite. Overlying Pleistocene deposits are highlighted by the Harling Point erratic and glacial grooves and striae.
The Harling Point Erratic, also known as Harpoon or Devilfish Rock, is exceptional both in appearance and location. So distinctive is its appearance that oral legends among the Songhees First Nations people about this stone have been passed down to the present day. The stone’s vertical orientation is said to have resulted when a disrespectful complaining seal fishermen was turned into a stone harpoon by the angry Transformer. Another legend explains that if one were to walk out to the stone and touch it (low tide is necessary) the protein rich devilfish (Pacific octopus) would rise up and be easily captured.
The setting of this large vertical stone is remarkable as well. It sits on a bedrock platform scoured by sediment carried in the base of the Vashon glacial lobe around 15,000 years ago. The large, long parallel grooves are unmistakable. It is easy to imagine (if not correctly) that this very stone was responsible for the groove it straddles.
The rock at the point underlying the recent till deposits is worth examining closely. You will see two distinct types of plutonic rock, mixed together to make the metamorphic rock migmatite. This is a little complicated. The gray, pale green-gray and blackish rocks are gabbro, the plutonic equivalent of basalt. The main mineral phases are calcium-rich plagioclase feldspar and pyroxene. The other rocks are light colored granodiorite, very similar to the big erratic. The light color stems from a predominance of white plagioclase and quartz, with a subordinate sprinkling of the usual dark minerals biotite and perhaps hornblende. These two plutonic rocks have very different in compositions, yet are mixed together and visible at a number of locations in the Victoria area. According to Yorath and Nasmith’s excellent book, The Geology of Southern Vancouver Island, these plutonic rocks belong to the Saltspring Intrusions. Along the Victoria area shoreline, they have intruded into the Wark and Colquitz gneiss complexes, which were metamorphosed some 200 million years ago, when these rocks all lay somewhere far off the coast of North America, and deep inside a microcontinent plate moving toward the margin of North America. Migmatite forms at high temperatures and pressures. The rocks that are mixing are just hot enough that those with low enough melting points, such as the quartz and plagioclase rich granodiorite, do so. Conditions are extreme enough that almost all the different rocks deform plastically, schmmmmmmmmmmmearing out and mixing intimately (ahem). Sort of a, dare we say it, geo-orgy.
To quote from a helpful website by AGU about migmatites, “Migmatites actually look very similar to a related rock: gneiss. Gneisses also contain alternating light and dark layers which result under high-pressure and high-temperature conditions. However, in a strict definition gneisses are metamorphic rocks, which means that the light bands form through recrystallization alone; the light layers did not form by cooling from a melt. Distinguishing between gneisses and migmatites can be slightly challenging to do in the field. The two rock types are certainly relatives, so to speak. If a gneiss experiences just slightly higher temperatures, it may partially melt and become a migmatite. Most migmatites probably were gneisses on their way to becoming true hybrid metamorphic-igneous (metagneous? ignamorphic?) rocks.”
A Victoria-based website, JamesBay.org , discusses geology along the shoreline immediately to the west at Finlayson Point here. This website also uses Yorath and Nasmith as a reference.
The human history of this area is also outstanding. Besides the millennia of use by the indigenous people this small point figured in the more recent history of a colony and later a young nation. In the time of sailing ship dominance the point was known as Foul Point for the many submerged rocks that could damage or sink ships rounding too close to shore. In the early 1900s, displaced Chinese immigrants made this deserted piece of land the location for their cemetery (website here) with its rare funerary burner, at which time it was called Chinese Point. In the 1930s a local dentist, Dr. Fred Harling, died while attempting to rescue a family caught in a small boat during a storm off this point. It was subsequently renamed Harling Point to honor his bravery and selfless sacrifice.
When visiting Harling Point be respectful of the cemetery and funerary structures which are part of the National Historic Site. Interpretive panels describe the point’s cultural history, geology, and natural history including the rare and protected flowers that bloom in the spring. A trail corridor located outside the southeast entrance to the cemetery, allows for a short pleasant hike to or from Trafalgar Park Lookout on a bluff a short distance to the east on equally scenic Beach Drive. Inland and above the cemetery but clearly visible are the interesting summits of Gonzales and Walbron Parks. Seaward views from the shoreline and the surrounding parks are exceptional.
For an interesting walk along more glacial “tracks” visit nearby Westsong Way along the west shore of Victoria’s Inner Harbor (coming next on Northwest Geology Field Trips). You can record the orientation of the glacial grooves with a compass and compare them to different locations and see for yourself the deflection forced on the glaciers as they rounded the southern end of Vancouver Island.
2099 Penzance Rd, Oak Bay, Vancouver Island; approximate coordinates N 48° 24.348′ W 123° 19.338′
From the south shore of Victoria below Beacon Hill, follow scenic Dallas Road east and continue as it becomes Crescent Road in Oak Bay. Soon after passing Gonzales Bay, follow Crescent Road as it turns sharply south (right). In a short distance take Penzance Road angling off to the left and continue along the cemetery fence-line to the east gate. The Harling Point erratic can be found through the gate and directly south close to shore but in the tidal zone. It is best seen or visited during lower tides. Please be respectful of the cemetery and protected natural areas. BC transit buses from downtown go to the Gonzales stop, only two blocks north of the point. BC Transit Map Route 3 from Downtown to the Gonzales stop.