Stoping is a process accommodating the ascent of

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

tic bodies from their sources in the mantle or lower crust to the surface. The theory was independently developed by Canadian geologist Reginald Aldworth Daly and American geologist Joseph Barrell.1925. ''Biographical Memoir of Joseph Barrell'' by Charles Schuchert
/ref> The process involves the mechanical disintegration of the surrounding

country A country is a distinct part of the world, such as a state, nation, or other political entity. When referring to a specific polity, the term "country" may refer to a sovereign state, state with limited recognition, constituent country, ...

/host rock, typically through fracturing due to pressure increases associated with thermal expansion of the host rock in proximity of the interface with the melt. After fractures are formed, melt and/or volatiles will typically invade, widening the fracture and promoting the foundering of host rock blocks (i.e. stoped blocks). Once suspended in the melt, stoped blocks may either sink or float depending upon the

density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

of the block relative to that of the melt. Additionally, blocks submerged within melt are subject to further thermally-induced fracturing which may account for the often observed "lack of evidence" for the process of stoping.

References

Igneous petrology Geological processes {{igneous-petrology-stub

See also

References