They once generated enormous volumes of basaltic lava across Idaho’s Snake River Plain.
他们曾经 在爱达荷州的蛇河平原产生了大量的玄武岩熔岩。
英语百科
Snake River Plain
The Snake River Plain is a geologic feature located primarily within the state of Idaho in the United States. It stretches about 400 miles (640km) westward from northwest of the state of Wyoming to the Idaho-Oregon border. The plain is a wide flat bow-shaped depression, and covers about a quarter of Idaho. Three major volcanic buttes dot the plain east of Arco, the largest being Big Southern Butte.