lava | Stoness Travel Blog

Basalt lava flow covered with mosses and lichens

Volcanoes are not choosy. They erupt wherever they can, and whenever they are ready. Two hundred and fifty years ago a terrible calamity hit the Nass River Valley in British Columbia. A volcano erupted and spewed lava down the hillside into the valley and then flowed northward to burn and bury two villages of the Nisga’a aboriginal tribe. The gases and the lava killed over 2,000 natives. The flow buried some of the original channel of the Nass River and pushed the entire river northward across the valley to its present location.

Today, a 179 square kilometre park is preserved as a memorial to those families who

perished. The park is managed together by the aboriginals and the Provincial Government. If you visit you will find a campground with 16 sites, and a colourful Visitor Centre which may have a resident artist on duty during the summer time. There are also maps of the track of the lava flow, and native artefacts.

Solid blocks of lava thrown upward as lava pushed

A guided tour will take you on a trail to the lava cone. The trail is moderately hard so wear good hiking boots for the 4 hour hike which takes you 3 kilometres over the lava to the cone.

If you travel from Terrace, heading north, you will see Lava Lake. This lake is the result of the lava damming the river. Often the river now flows under the lava and is out of sight in places. The basalt lava flow is extensive and very interesting to examine as you follow trails across the surface. Normally you would find basalt lava to be very black. In the lava field it has a surface coating of lichens and mosses and looks somewhat tan, or yellow. Do not leave the trail as it destroys this new vegetation which is slowly turning the basalt into soil.

Notice how the surface is often buckled, and heaved up in blocks. This is caused by the lava surface solidifying or freezing, while underneath, the lava was flowing quickly. This is similar to a stream with ice flows. Sometimes the flow would pushNisga’ upward, and blocks of basalt would flow and jam causing even more buckling of the crust. You will see

these areas and realize the tremendous

Hole in frozen lava caused when lava flowed around a living tree, which later rotted.

force and pressure required to redesign the landscape in this manner. If you follow Tree Mould Trail you will see several examples of this, and you will see a hole through the rock formed when lava flowed around a live tree and solidified. Later on the tree rotted leaving the round tunnel through the rock. Some blocks whose edges you can see show multiple holes. These were gas bubbles that were trapped in the freezing lava.

There are also attractive rapids and waterfalls.

The drive in from Terrace is very scenic with great views of the mountains. Then suddenly you are on top of the lava beds. Take time to go and visit the site of Canada’s last volcanic eruption.

Happy RVing!

For more than four decades James Stoness has travelled the roads of North America, photographing and writing about what he has seen. His travel articles and beautiful pictures have been published in several magazines and newspapers. He is also the author of five western novels. Visit his website at: www.stonesstravelguides.com

Before it was something for humans to worry about , the North American Continent was wracked by huge volcanic eruptions the like of which humans have never seen. Those who travel to Yellowstone National Park observe the eroded remnants of these calamitous explosions which form the Yellowstone Caldera.

Yellowstone NP is the youngest of a string of calderas stretching from Oregon to Wyoming. One theory is that about 17 million years ago a meteor plunged through the earth’s crust into the underlying mantle which released the pressure below and a massive eruption followed.

The question is then, how come there is a caldera at

Yellowstone in Wyoming, when the hotspot was created in Oregon? Well,the answer is a bit confusing. The hotspot never moved. It’s still where it was created 17 million years ago. Instead Yellowstone NP is now sitting over the hotspot because the crust of Central North America is slipping southwest at about 2” each year, so 17 million years later, Wyoming is sitting where the old Oregon would have been.

There are other theories, but I like this one. Now, on the crustal journey southwest as the crust moved across the hotspot the eruptions would cease for a time, and then pop up sort of like a cutting torch punching through steel, and then there would be another huge eruption and another caldera. There is a chain of the calderas running northeast across the country from Oregon to Wyoming.

These eruptions are so severe because the eruption releases rhyolite magma. Rhyolite

magma has the ability to absorb huge quantities of water which remain absorbed so long as the pressure is kept on the top. Release the pressure by cutting through the crust and the steam expands in a massive explosion carrying magma and anything else in the way to the surface. Great clouds of hot rock move across the landscape in great pyroclastic flows that weld together forming tremendous cliffs of soft rock.

When you travel in Yellowstone NP some of the great cliffs are the result of these cooling pyroclastic flows. If you try to follow the trail of the calderas you will find it difficult to see much. Erosion has done its work and many of the old calderas are flattened. Highways pass right through the Rexburg Caldera but you’d not know it was there.

Your drive is made interesting by secondary eruptions that have occurred across these plains and have spewed out a very liquid black basalt lava which has created

very interesting lava beds, and nearby there may be cinder cones from which the lava often flowed. Craters of the Moon National Monument has preserved many of these lava flows and has good examples of cinder cones.

Whether at Yellowstone National Park, or areas farther west you will find interesting scenery, and great camping. Take some time and explore.

You can find more information and maps showing some of these features in my scenic tours book, “The Lure of Pine and Sage”, which is available as a download from my website, www.stonesstravelguides.com

Tag: lava

Nisga’a Memorial Lava Bed Park

On the Trail of the Giant Calderas