Author Archive

FRASER VALLEY FORMS

February 16, 2010

Preamble:

Distance, to paraphrase, is Nature’s way of keeping everywhere from being in the same place. Hence we need transportation.

While Zweisystem is taking a breather, I’ve been asked for some thoughts. Rail for the Valley takes on a broader meaning if we use “rail” in the sense of “argue vociferously”. I’d like to do a little railing. Think out loud about moving people and stuff from place to place in the Fraser Valley.

In 1998 or thereabout a rascal named Jim Wallace raised the prospect of revitalizing the Fraser Valley Interurban during a meeting of the Surrey Heritage Commission, which I was chairing at the time. The next weekend, with my grandson as navigator, we traced the tracks from Brownsville, on the Fraser River to Chilliwack. It was obvious. The track was there and used for freight. It would be dead easy to reinstate Passenger traffic.

During the intervening years, a lot of material has been collected. I’d like to pass it along to this forum, together with occasional thoughts. Here goes.

Making the Valley

Might as well start at the beginning. Visualize the Fraser Valley:

This triangle of green is clearly visible from space; a distinct fertile, flat form. An ideal place for people to settle. Where people settle, semi-paradoxically, they need to move around.

The map below shows the mouth of the Fraser River at the end of the last ice age, an ice choked fjord dotted with islands. For 15,000 years, the Fraser River has conveyed silt from the Interior to the Salish Sea. Think of Sumas Mountain as a valve.

Originally the river ran south of Sumas Mountain with a main stem following the alignment of the Nooksack River through a delta.

The early Fraser Valley formed as a delta south of Sumas Mountain.

The oral tradition of the Tswwassen people tells of their ancestors standing on Mount Sleese and seeing their future Point Roberts home as an island across an inland sea.

The maps show water in dark blue, elevations above 300 metres in white and green is the “bottom land” of the Fraser Valley. 

The soil of the valley was pushed here by glaciers and deposited, particle by particle, by the river. The result is a tumultuous series of soil profiles. Glacial till offers firm bearing and resists erosion in some places, while soft alluvial deposits underlie marshes in others. As the delta developed, life, including people, advanced westward with the edge of the land.

At some point the channel south of Sumas mountain silted up or an ice dam melted and the main stem flipped to the north side. A new delta began forming.

Later the main stem of the river switched to the north side of Sumas Mountain and the delta was pushed west.

Here is our basic land form, a V-shaped alluvial valley about 140 kilometres long, set in a wedge of mountains with salt water to the southwest. Because the whole landscape had been depressed by the weight of ice several miles thick, there was rebound. The old delta to the south (now mostly in the United States) is higher than the new delta. Glacial rebound continues.

This is a very simple version of the story. The Geological Survey of Canada provides more detail at:  http://gsc.nrcan.gc.ca/urbgeo/geomapvan/geomap3_e.php

For at least 10,000 years, the Fraser Valley has been an ideal place for people to settle. And where people are settled as noted above, they are going to want to move.

Respectfully Submitted

Terry Lyster

Advertisements