Cannonball rock formations found in Summerland being studied by geologists

Rare 'cannonball' rocks

Casey Richardson

Have you found a lava bomb, better known as a cannonball rock?

One Summerland historian is hoping the Okanagan community also has rocks similar to those in his collection to help geologists pinpoint whether their locations expand further than the one district. 

David Gregory has been collecting the spherical rock specimens for more than 30 years. Found in the hills of Summerland, the speculated main source of the lava coming from one of the extinct volcanoes: Rattlesnake Mountain.

“The Summerland area is a geological wonderland,” Gregory said. “As we keep studying it, there is more and more to the story.”

He first found some of the rocks when hiking through the area, which could be as old as 55 million years. Described as having a crusty surface texture, a spherical shape that can sometimes form into a teardrop and a solid inside with no crystallization, the size can range from that of a ping pong ball to two metres across. 

“It’s a pretty dense rock, so when you pick it up, it’s heavier than you think. When you extract it from the rock, you have to be really careful because any stress put on this, it’ll split exactly in half.” 

“Almost all longtime Summerland people have collections of cannonballs, almost everybody. If people have lived here a long time they got one or two cannonballs in their backyard,” Gregory chuckled. 

While the cannonball rocks are thought to be created from extinct volcanoes in the area, their exact formation is still being looked into.

“They’re looking at density because density is pretty important for, you know, is it really lava related. It surely is,” Gregory said. “How it forms spheres like this, there’s some physics behind how these are formed, and I think that’s what they’re thinking about. It’s dripping already in a lava lake with water and volcanic ash.”

“It’s a lava bomb or similar to a lava pillow. I thought it was formed by the volcano spitting the lava into the air and the air creates a raindrop shape, and then it falls into the water and it quickly cools. But the latest thing is we think it was already in the water.”

The stones have gained such an interest that the Fitzpatrick Family Vineyard wanted to display them and use them as inspiration for their wine. 

“We like to tell stories and every good bottle of wine should have a story,” said Gordon Fitzpatrick, winery president.

“Just because of the relationship with geology and the dirt that we’re working with, we just thought it was fun to share that with the visitors.”

The winery became aware of the rocks when Gregory was doing one of his history lectures at the Fitzpatrick Winery and shared the cannonball story at the end.

“People loved the story, and they (the winery) said ‘Hey let’s do a cannonball wine.’ I said ‘Okay, well if you’re going to do that I’ll give you my best cannonballs.” 

From this, the winery first did a specialty sparkling wine but liked the name so much they’re using it for another upcoming creation with grapes grown in Summerland.

“We’re going to be releasing about this time next year a Gamay that we’re calling our Cannonball Gamay in honour of these interesting geological activities.”

Gregory hopes to continue sharing the story of the Summerland cannonballs and find out where others have found these spherical marvels to pinpoint how far these rocks reach. 

”We have one for sure in Naramata, it looks exactly like these. There might be one from people who phoned me yesterday from the pincushion mountain in Peachland.” 

If you’ve found any lava drops, contact Gregory at 250-494-9030 to show off your findings.

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