Basalt is usually formed when lava solidifies on the earth’s surface ... The sediment comes from eroded rocks carried there by rivers or ice, and from the skeletons of sea creatures.

The latest incident started at about 10:16 a.m. when the vents began pouring the molten rock onto the floor of Halemaumau Crater, according to CBS News. A half-hour later, lava burst out of a vent ...

Now, an investigation of ancient lava formations by ... among those who thought the rocks were volcanic, which has since proved to be the case. That means wind erosion likely scoured sedimentary ...