POSTED: Sunday, Feb. 07, 2010

Bellingham geologist creates Web sites about rocks in region

BELLINGHAM - Walk in Arroyo Park with Bellingham resident Dave Tucker and you get more than pleasant conversation in a pretty, wooded setting.

You'll get to hear the geologist talk about time stretching back millions, maybe hundreds of millions, of years. You'll learn about hot, flowing rock that eventually cooled and pushed through the Earth's crust. You'll ponder over that same rock, which fell on a glacier and was transported from somewhere up in the Coast Mountains of British Columbia and dumped in Arroyo Park by the river of ice.

And you thought that was just a dull-looking boulder alongside the Hemlock Trail - crisscrossed by fallen trees and covered in greenish vegetation that makes it look like nature's Chia Pet.

"There's a lot of story in this rock," said Tucker, a 59-year-old research associate in the Geology Department at Western Washington University, while standing next to it.

"Unfortunately, we can't see a whole lot of it because of the vegetation. But it's a cool one. It's amazing the number of people who don't even know it's here," he added.

More people will know about it in the future, thanks to a Web site that Tucker launched in December called Northwest Geology Field Trips, which features write-ups of the geology of northwest Washington and southwest British Columbia.

They are hiked and written up by Tucker, who also posts pictures and directions. Some of the hikes are easy and easily accessible. Others are leg-burners or require travel further afield.

"The idea is for people to go in there (the Web site) and find a field trip that interests them," he said of the self-guided outings that are at nwgeology.wordpress.com.

The geology educator said he launched the Web site to also reach "armchair geologists" - a group he described as "people who are just curious about nature."

"There's a phenomenal amount of interest in geology in the Northwest. I cannot give a lecture without it being packed to the gills and it's not me, it's the subject," said Tucker, who also is working on two guide books.

His interest in geology has been lifelong.

"As a kid I grew up in the Northwest (in Steilacoom), and I saw volcanoes all around me," he said. "If you're at all interested in the outdoors, you can't help but have an interest about what makes the Earth the way it is here."

The former professional mountaineering guide earned a graduate degree in geology at WWU in 2004, although his primary source of income is his roof- and gutter-cleaning business.

He has given talks about Mount Baker, which is an active volcano, and is known for his research of volcanoes in the North Cascades. He's also led field trips through North Cascades Institute as well as geology tours of downtown Bellingham for a class he created for the Academy for Lifelong Learning through WWU.

During the recent outing to Arroyo Park and Donovan Avenue in Fairhaven, Tucker did a show and tell of Bellingham-area glacial erratics featured on his new Web site.

Such rock forms were essentially brought elsewhere to this area by a glacier.

That's the case of the Arroyo erratic, which came to Whatcom County from British Columbia.

"We can tell it's been glacially transported because the surfaces are kind of planed off where they've been ground underneath the ice," he said while standing next to the Arroyo erratic.

He pointed to fine veins running through the granitic rock, veins that were caused by thin molten material moving up into fractures in the rock before crystallizing.

Tucker then walked a few steps and picked up pieces of the local bedrock, known as Chuckanut sandstone.

It is about 50 million years old and used to be river sand. "It's pretty friable. It just breaks apart," he said.

At Donovan Avenue, he talked about a line of rocks near Interstate 5 that looked - at least to the untutored - unremarkable.

The weathered rocks belonged to a towering boulder that was dynamited to pieces in 1965 to make way for the freeway. That boulder started out in the Pacific Ocean about 200 million years ago.

It used to be on the sea floor of an ancient ocean, and plate tectonics carried that floor along until it hit North America. There, earth forces couldn't push all of the floor underneath the North American plate. A slab was scraped off and got stuck to North America.

At some point, it fell down onto the continental ice sheet and was carried from an area near present-day Hope, B.C., and Manning Provincial Park and dropped off at present-day Donovan Avenue about 11,000 or 12,000 years ago.

Known as Jackass Mountain Conglomerate, it is a mish-mash of different rocks such as granite, sandstone and lava. But it's not from outer space, as some locals have long believed. At least that's what one man told Tucker in an e-mail.

"It's not a meteorite," Tucker said. "It would be cool if it was."

ON THE WEB

Find Bellingham resident and geology educator Dave Tucker's Web site focusing on self-guided walks and hikes of the region's geology at nwgeology.wordpress.com. He created the site, Northwest Geology Field Trips, in December.

MOUNT BAKER TALK

What: Dave Tucker, a research associate in the Geology Department at Western Washington University, will give a talk on the eruptive history and hazards of Mount Baker, which is an active volcano.

When: 2:30 to 4 p.m. Thursday, Feb. 18.

Where: Skagit Valley College, 2405 East College Way in Mount Vernon. The talk will be in Lewis Hall Room 65 (L-65).

Who can go: The event is open to the public.

Cost: Free.

Details: David Muga, (360) 416-7665.