Quenched Blobs

Lava that was erupted on May 19 and 22, 1915 contained many dark blobs whose compisitions were different from the host lavas. The compositions and shapes of these blobs show that they come from a hotter, deeper source. When this hotter liquid rock (magma) was injected into the cooler dacite magma beneath Lassen Peak, it congealed into blobs.