Antler orogeny Antler orogeny in detail and somewhat refined its age span: "During the Antler orogeny, formations in Battle Mountain ranging in age from Ordovician to Mississippian (?) were complexly folded and faulted. As these rocks are unconformably overlain by the Battle Formation of Early Pennsylvanian (Des Moines) age, the orogeny probably took place during the Late Mississippian. The orogeny may have continued into Early Pennsylvanian, however, for the coarse conglomerates of the Battle Formation indicate derivation from a rugged highland area." In a subsequent influential paper, Roberts and others adjusted the age of the Antler orogeny as follows: "This belt is
Svecofennian orogeny rocks and the emplacement of the Jormua and Outokumpu ophiolites about 1950 million years ago. In the later stages of the Lapland-Savo orogeny an island arc, the Knaften arc, accreted to the Keitele-Karelia-Norrbotten collage. The stage to the Fennian orogeny was set by a collision between Keitele and Karelia about 1920–1910 million years ago which resulted in a reorganization of the local plate tectonics. As concequence the Bergslagen microcontinents collided with the Keitele–Karelia collage starting the Fennian orogeny. The until then linear Fennian orogen was "buckled" from 1870 million years ago onwards due to an orthogonal change in tectonic compressive