Link to USGS home page.
USGS HOME
Contact USGS

  • Assess
  • Prepare
  • Forecast
  • |
  • Activity
  • Products
  • Observatories
  • About

Glossary - Dike

Dike

Dikes are tabular or sheet-like bodies of magma that cut through and across the layering of adjacent rocks. They form when magma rises into an existing fracture, or creates a new crack by forcing its way through existing rock, and then solidifies. Hundreds of dikes can invade the cone and inner core of a volcano, sometimes preferentially along zones of structural weakness.


Glossary Terms


A
B
C
D
E

F
G
H
I
K
L
M
O
P

Q
R
S
T
U
V