What are discordant plutons that cut across the layering of the host rock called?

Discordant plutons that cut across the layering of the host rock are specifically referred to as dikes. A dike is a type of igneous intrusion that forms when magma moves through pre-existing rock layers, forcing its way and solidifying into a vertical or steeply inclined structure. This cutting across of the layering is a key characteristic of dikes, distinguishing them from other types of plutons that typically conform to the original layering of the host rock.

In contrast, batholiths and stocks are larger intrusive bodies that generally form from the accumulation of magma over time, often resulting in a more regional or massive intrusion that can exhibit a high degree of concordance with the surrounding rock layers, at least in terms of their overall outlines. Laccoliths are another type of intrusion that typically cause the host rock layers to arch upwards while remaining mostly conformable, which contrasts with the disruptive nature of dikes.

Understanding the definitions and characteristics of these terms helps in recognizing how they relate to geological formations and processes, as well as their significance in mining and geological studies.