- Columbia River Basalt Group Stretches from Oregon to Idaho (usgs.gov)
The thick, layered lava flows of the CRBG erupted as flood basalts, which originate as some of the most highly effusive eruptions in the world. The CRBG sequence a classic example of flood basalt activity that erupted more than 350 lava flows from about 16.7 Ma to 5.5 Ma. The eruptions originated from a series of generally north-northwest-trending linear fissures, ranging from tens to hundreds of kilometers in length, located along the Washington/Oregon/Idaho border. The magma that fed these massive eruptions may have come from a plume-like upwelling from the mantle called a hot spot. Since the time of the CRBG eruptions, the North American plate has moved in a west-southwestwardly motion, and that hot spot is now believed to reside beneath Yellowstone volcano in northwest Wyoming.
- Twoflower (Wikipedia)
Twoflower is a native of the Agatean Empire, on the Counterweight Continent, living in the major sea port of Bes Pelargic where he works as an “inn-sewer-ants” clerk where he calculates the level of insurance premiums. The first tourist ever on the Discworld, he wrote “What I did on my Holidays” after his return to the Empire.