Lopolith

A Lopolith is in geology a specific expression of a form igneous plutons. The solidified body of rock is formed into a central bowl- shaped depression.

The intrusion is essentially concordant with the surrounding layers. The migration pathways of igneous material are either schlot shaped or formed as Dykes.

Lopolithe are found in rock units of all ages, from the Archean up to the Eocene. They are often built up layers of large ultramafic and mafic layers. Gabbro is a common rock in Lopolithen.

Examples are the Sudbury Igneous Complex in Ontario, the Bushveld complex in South Africa, the Skaergaard Complex in Greenland and the Humboldt Lopolith in Nevada. The occurrence of Sudbury and Bushveld were related to large meteorite impacts and associated melting of Erdkrustenmaterial.

The Duluth Gabbrokomplex, who had been regarded for a long time as the archetype of a Lopoliths, proved to be approximately 16 km powerful storage aisle.

Defines and first used the term was by Frank Fitch Grout beginning of the 20th century in the description of the Duluth Complex in northern Minnesota and adjacent Ontario.