Buen Formation


The Buen Formation is a geologic formation and Lagerstätte in Peary Land, North Greenland. The shale preserves fossils dating back to the Early Cambrian period.

Description

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

The following fossils have been reported from the formation:
GroupTaxonImageNotes
AnnelidsPhragmochaeta canicularis
ArthropodsBuenaspis forteyi
ArthropodsBuenellus
ArthropodsAaveqaspis
ArthropodsKerygmachela
ArthropodsTamisiocaris
ArthropodsLimniphacos
ArthropodsWaptia
ArthropodsKleptothule rasmusseni
ArthropodsIsoxys volucris
ArthropodsHadranax augustus
ArthropodsPauloterminus spinodorsalis
MolluscsHalkieria evangelista
DemospongesChoia hindei
OthersHeliosphaeridium dissimilare
OthersTrapezovitus malinkyi
OthersKalaallitia myliuserichseni
OthersNasaaraqia hyptiotheciformis
OthersNevadotheca boerglumensis
OthersSullulika broenlundi
OthersAlutella siku