Evergreen line gets scientists to core of Lower Mainland

TRI-CITIES (NEWS 1130) – As the new Evergreen SkyTrain extension takes people to work, it’s also transporting SFU scientists back in time to better understand what the Lower Mainland looked like thousands of year ago.

Core samples taken from the tunnel section of the new line were donated by the construction company and offer a glimpse into the region’s geological past.

The core pieces were taken when workers encountered sinkholes in the tunnels and range between 48 and 130 metres in length.

“To pay for this kind of coring is far outside the budget of any university researchers, and we were just very lucky to get access to them,” earth science professor Brent Ward says.

“They go through a bunch of sediments that tell us about glaciation in the Lower Mainland over the last, at least 100,000 years. It’s an amazing window on geologic time that we now have access to.”

Ward says they’ve already uncovered evidence which suggests the area between Burnaby Mountain and the upper surface of Coquitlam used to be a large valley. Compacted sediment was found in places where scientists originally expected to find bedrock.

They also found volcanic ash which could be from extinct volcanoes that once exploded in the surrounding area.

Ward says the samples help them reconstruct glaciers and old sea levels, but it will also help modern engineers understand the land they are building on, and what equipment they might need.

“Better understanding [what’s below the ground] actually assists the engineers when they’re designing things,” he says.

Ward wants to preserve the core samples so future students can study and learn from them.