Late Cretaceous to early Paleocene deformation and metamorphism of strata of the Kahiltna basin varies in depth and style from east to west during the collision of the Wrangellia composite terrane. In the east, the Maclaren Glacier metamorphic belt experienced kyanite-grade regional metamorphic conditions of 650 °C at >670 MPa during top-to-the-south thrusting. About 100 km along strike to the west, the Devil Creek area experienced contact metamorphic conditions at 300 MPa forming andalusite, with sillimanite migmatite near pluton margins. Three plutons from the Devil Creek area yield U-Pb zircon ICP-MS dates of 68.3 ± 2.6 Ma, 66.1 ± 2.6 Ma, and 62.6 ± 2.1 Ma, which we interpret to be the crystallization ages of the plutons. In the Maclaren Glacier metamorphic belt, a 74 Ma, 1-kilometer-thick tonalite sill intruded during top-to-the-south thrusting. In the Devil Creek area, pluton emplacement occurred during NW-SE shortening and NE-SW near horizontal stretching. The age dates suggest that deformation and metamorphism in these two areas was diachronous, and the difference in depth of metamorphism of at least ∼14 km between the Maclaren Glacier metamorphic belt and Devil Creek shows that exhumation of the strata of the Kahiltna basin was greater in the eastern part of the Alaska Range suture zone.

Several narrow terranes occur along the Denali fault in the Eastern and Central Alaska Range in Southern Alaska. These terranes are the Aurora Peak, Cottonwood Creek, Maclaren, Pingston, and Windy terranes, and a terrane of ultramafic and associated rocks. Exterior to the narrow terranes to the south is the major Wrangellia island arc composite terrane, and to the north is the major Yukon-Tanana metamorphosed continental margin terrane. Overlying mainly the northern margin of the Wrangellia composite terrane are the Kahiltna overlap assemblage to the west, and the Gravina-Nutzotin-Gambier volcanic-plutonic-sedimentary belt to the east and southeast. The various narrow terranes are interpreted as the result of translation of fragments of larger terranes during two major tectonic events: (1) Late Jurassic to mid-Cretaceous accretion of the Wrangellia island arc composite terrane (or superterrane composed of the Wrangellia, Peninsular, and Alexander terranes) and associated subduction zone complexes; and (2) starting in about the Late Cretaceous, dextral transport of the Wrangellia composite terrane along the Denali fault. These two major tectonic events caused: (1) entrapment of a lens of oceanic lithosphere along the suture belt between the Wrangellia composite terrane and the North American Craton Margin and outboard accreted terranes to form the ultramafic and mafic part of the terrane of ultra-mafic and associated rocks, (2) subsequent dextral translation along the Denali fault of the terrane of ultramafic and associated rocks, (3) dextral translation along the Denali fault of the Aurora Peak, Cottonwood Creek, and Maclaren and continental margin arc terranes from part of the Coast plutonic-metamorphic complex (Coast-North Cascade plutonic belt) in the southwest Yukon Territory or Southeastern Alaska, (4) dextral translation along the Denali fault of the Pingston passive continental margin from a locus along the North American Continental Margin, and (5) formation and dextral transport along the Denali fault of the mélange of the Windy terrane from fragments of the Gravina-Nutzotin-Gambier volcanic-plutonic-sedimentary belt and from the North American Continental Margin.