Granite-Gabbro Relations in the Mineral Lake Instrusive Complex

Abstract

The Mineral Lake Intrusive Complex (MLIC) is a Layered Ma c Intrusion (LMI) located in northeastern Wisconsin. Granitic and gabbroic rocks are intimately associated in the MLIC, with each rock type often containing inclusions of the other. The relationship of these two magma types is the subject of some debate among geologists. Recently, we have developed an alternative model for the origin of granite in LMIs. The model holds that both the granitic and gabbroic rocks were derived from a common parent magma that experienced liquid immiscibility as crystallization proceeded. Here we examine the major and trace element variations of MLIC rocks to test this model for the origin of granite.