Granodiorite of Mount Evans batholith

What the map says

Gray, massive to strongly foliated, coarse-grained, mostly porphyritic biotite-hornblende granodiorite, which ranges in composition from monzogranite to tonalite (Aleinikoff and others, 1993a). Locally contains as much as 5 percent of an aplite-pegmatite phase consisting of dikes and irregular-shaped bodies of massive to weakly foliated aplite and magnetite-bearing pegmatite. Formerly believed to be part of the Early Proterozoic Routt Plutonic Suite of Tweto (1987), due to petrographic and textural similarities to rocks of that suite and limited Rb-Sr data (for example, Bryant and Hedge, 1978). However, U-Pb zircon date is 1,442±2 Ma (Aleinikoff and others, 1993a), confirming emplacement with Middle Proterozoic Berthoud Plutonic Suite of Tweto (1987)

1:100,000 sheet: Kellogg and others, 2008, USGS Geologic Investigations Series 3000 (17 crags). A contact line at that scale is about 100 m wide on the ground.

Served by Macrostrat (CC BY 4.0). The wording is the map's own, quoted as a fact about the mapped unit, not about any one wall.