The YTT consists of polymetamorphosed and polydeformed metasedimentary, metavolcanic, and metaplutonic rocks of Upper Paleozoic and older ages that were deposited or emplaced near the edge of the North American continental margin. Rocks in the terrane record a variety of tectonic settings and have experienced varying amounts of tectonic transport, both before and after amalgamation of the YTT with North America. Sequences of mainly
parautochthonous quartz-rich sedimentary rocks derived from the North American continent also include meta-igneous rocks with mostly continental geochemical and isotopic signatures. Structurally higher sequences contain meta-igneous rocks with arc and back-arc characteristics. The
Slide Mountain/Seventymile terrane, composed of volcanic rocks typical of seafloor and of typical seafloor sediments, is recognized as an ocean basin that divided parts of the YTT before amalgamation of the Yukon–Tanana terrane with the continental margin. The right-lateral strike slip
Tintina Fault occurs along the suture zone between the YTT (on the south and west) and ancestral North America to the east; it forms a significant boundary between North America cratonic rocks and rocks of the YTT and associated terranes, although displaced continental rocks are found south of the Tintina Fault and pieces of the YTT occur north of the Tintina Fault. Parts of the YTT have been offset by at least along the Tintina Fault. In most of the Alaskan part of the YTT the
Denali Fault forms the modern day southern boundary of the terrane. In Yukon the ocean-basin rocks of the
Windy–McKinley terrane (in western Yukon), and the
Coast Plutonic Complex (CPC) form the southern boundary of the YTT. Units assigned to the YTT also occur within the CPC; and the YTT partially encloses and is complexly related to the
Intermontane superterrane (together with the
Stikine,
Cache Creek, and
Quesnel terranes). ==Metal mineralization==