Laccolith
（重定向自Laccolite）
![A laccolith intruding into and deforming strata](/Images/godic/202501/23/Laccolith.svg0600.png")
![Laccolith exposed by erosion of overlying strata in Montana](/Images/godic/202501/23/Laccolith_Montana0600.jpg")
![Pink monzonite intrudes within the grey Cambrian and Ordovician strata near Notch Peak, Utah](/Images/godic/202501/23/NotchPeak0600.jpg")
A laccolith is a sheet intrusion (or concordant pluton) that has been injected between two layers of sedimentary rock. The pressure of the magma is high enough that the overlying strata are forced upward, giving the laccolith a dome or mushroom-like form with a generally planar base.