Upper Ordovician and Silurian carbonate shelf stratigraphy, facies and evolution, eastern North Greenland

Abstract

A new lithostratigraphic scheme is erected for the uppermost Ordovician and lower Silurian shelf carbonate rocks of Peary Land and Kronprins Christian Land, eastern North Greenland. All carbonate rocks were deposited on a fairly stable shelf which was bordered to the north and east by deep-water basins. The shelf foundered in the latest LIandoverian, terminating carbonate production. Five formations and two members are defined and extend from the uppermost Ordovician (Cincinnatian) to the uppermost LIandoverian, or possibly lowermost Wenlock in the Silurian. Lithostratigraphic units include: Turesø Formation (new) composed of alternating light and dark grey peritidal to shallow subtidal laminated or massive dolomites, cryptalgal laminites and fenestral lime mudstones – uppermost Ordovician (Richmondian, Cincinnatian) to Lower or Middle Llandoverian; Ymers Gletscher Formation (new) composed of light grey peritidal lime mudstones, fenestral lime mudstones and cryptalgal laminites 0150 Lower to Middle Llandoverian; Odins Fjord Formation (new) composed of shallow to deep subtidal dark lime mudstones, wackestones and commonly floatstone and rudstone biostromes – Middle (possibly Lower) to Upper Llandoverian; Melville Land Member (new) composed of light grey peritidal lime mudstones, fenestral lime mudstones and cryptalgal laminites – Middle (possibly Lower) Llandoverian; Bure lskappe Member (new) composed of drowned shelf, dark grey to black laminated lime mudstone with terrigenous mudstone interbeds – Upper Llandoverian; Samuelsen Høj Formation (new) composed of light grey to white reef limestones – uppermost Llandoverian; Harefjeld Formation (new), a faulted, folded and cleaved black lime and terrigenous mudstone unit in eastern Kronprins Christian Land – Ordovician to Silurian (Llandoverian).