Antler orogeny it have been tried—east dipping subduction, west-dipping subduction, and strike-slip motion. None of them is without serious problems and the nature and driving force of the orogeny remain uncertain. This much is known concerning the Antler orogeny: Based on stratigraphic relations near Antler Peak, of the Battle Mountains, Roberts introduced the term Antler orogeny in an abstract as follows: "The earliest orogeny, here named the Antler orogeny ... took place during Mississippian (?) and early Pennsylvanian time." That abstract was followed in 1951 by his geologic map of the Antler Peak quadrangle in the text of which he described the
Grenville orogeny here. Ages are approximated from the magmatic activity associated with the individual cycles of the orogeny. The gaps in the ages of the compression cycles and isotope analysis of hornblende, biotite, and potassium feldspar suggest that extension was occurring when compression had momentarily ceased. Rivers' 2008 paper has now examined the timing of the different periods of the orogeny and reconstructed the timeline based on the spatial and temporal metamorphism of the rocks present. According to this newer version of the timeline which is a composite of Rivers 1997 and Gower and Krogh 2002, the Elzevirian orogeny occurs from 1240