Major episodes of Mesozoic plutonism in California correlate with periods of oblique subduction and trench-parallel transport of western California along intrabatholithic faults. Major episodes of plutonism occurred in the Late Jurassic, during left-oblique convergence, and in the mid-Cretaceous, during right-oblique convergence. In contrast, a conspicuous lull in plutonism (but continuation of volcanism) in the earliest Cretaceous coincides with a time when the North America-Farallon convergence vector, although large in magnitude, was oriented perpendicular to the trench. This correlation suggests that plutonism is facilitated by strike-slip faulting within the batholithic belt; one explanation, which helps to solve the plutonic room problem, is that plutons are passively emplaced at releasing bends in the strike-slip faults, and volume is conserved by thrusting at the trench. If this correlation is generally applicable, then it implies that mid-crustal plutonism is limited beneath arcs in which the convergence vector is subperpendicular to the trench. Continental growth in such arcs may occur dominantly by volcanism.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page of Plutonism, oblique subduction, and continental growth: An example from the Mesozoic of California
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.