Good morning! It’s our last full day here in Hawaii, and I’m writing this from the pool deck at our hotel here in Kona. Yesterday was quite a day, as I was finally able to share my topic with the group – xenoliths!
A xenolith is a rock that is trapped in/a part of another, different rock. It can occasionally be trapped in a sedimentary rock, but usually it’s in an igneous rock (a rock got trapped in magma and then the magma cooled around it). This normally happens when the current from the magma flowing below the earth’s crust is strong enough that a piece of the mantle breaks off and starts flowing with the magma.
The xenoliths we saw yesterday were from Hualālai’s 1800-1801 alkalic lava flows, which are actually famous for their unusually high quantities of xenoliths. We saw lots of olivine, peridotite, pyroxenite, and gabbro xenoliths. Some of them were from the mantle, but most of them were formed by built-up amounts of the minerals that crystallized from the magma before it erupted.
It was super cool to see the xenoliths and share what I had learned with everyone, and afterwards we each did a creative presentation that had something to do with Hawaii. We did a rap song – the lyrics are below – and the other group put on a skit! It was so much fun.
– Caroline
