The oldest Cambrian series of the area was deposited in the
Franklinian Basin and is poorly exposed in fragmentary, heavily metamorphosed outcrops in
Peary Land. It was emplaced during the
Ellesmerian orogeny.
Paleogeography During the Cambrian, Greenland was located in the southern tropical to temperate region. The Buen Formation forms part of the southern shelf succession of the Franklinian Basin of North Greenland and the Canadian Arctic Islands. The formation, approximately thick, consists of a lower, sand−dominated, member overlain by an upper member dominated by dark grey−green mudstones and siltstones in its type area in southern
Peary Land. It thickens to around in northern Peary Land where it comprises a mud−rich transitional succession into deep water trough deposits of the
Polkorridoren Group. Dark grey to black mudstones form part of this transitional succession from the shelf to the slope. To the south they lie in faulted contact with pale dolomites of the underlying
Portfjeld Formation, and to the north with bioturbated mudstones and sandstones of the Buen Formation. == Fossil content ==