A lot of people don’t know that San Diego has it’s own volcano that was active 15 million years ago.
The name is Calavera Volcano, and is located in Carlsbad, North San Diego County, California. Just across a valley from where I live. It’s a great place to hike and check out a little history.
What you see in the photos is what is called a plug.
A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of pressure if rising volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption.
This plug you see contains a fine – grain Basalt which actually clogged the volcano’s throat. After it’s last eruption, the cone slowly eroded, leaving only the plug which is pictured.
Check out the people on the top left corner for size reference.
Look closely and you can see people in the photos, which show the size of this plug. One of the people is my son, the other a friend of his.
They actually found a trail right up one of these veins, and climbed to the top of the rim.
So yes, San Diego County has it’s own Volcano.
Hope you enjoy!