Question R8 Q19 - NSB Round Robin 2009

When geologists find pillow basalts in ancient rock sequences, which of the following BEST explains their presence:

W) the area was once underwater

X) volcanic bombs and lapilli landed on snow or ice and quickly cooled

Y) they hardened in mid-air, sometimes forming a tear-drop shape

Z) nearby volcanoes erupted enormous quantities of ash

Science Bowl Question