Kimberlite source of mined diamonds today. The consensus on kimberlites is that they are formed deep within the mantle. Formation occurs at depths between , potentially from anomalously enriched exotic mantle compositions, and they are erupted rapidly and violently, often with considerable carbon dioxideand other volatile components. It is this depth of melting and generation that makes kimberlites prone to hosting diamond xenocrysts. Despite its relative rarity, kimberlite has attracted attention because it serves as a carrier of diamonds and garnet peridotite mantle xenoliths to the Earth's surface. Its probable derivation from depths greater than any other igneous rock type, and
Geology of the Lassen volcanic area called the Chaos Jumbles. The first and largest of these traveled downslope and was able to climb up the side of Table Mountain. The trigger for the rockfall is unknown, but it was most likely a large earthquake. Normal weathering also weakens fractured volcanic rock and contributes to small rockfalls. In the summer of 1994, a rockfall of occurred on the northeastern flank of Lassen Peak. During periods of extreme rainfall or snow melt, mudflows are sometimes generated by mobilization of loose volcanic debris and soil on the slopes of volcanoes. The only current visible activity in the Lassen volcanic