The formation, named by Laird in 1963, crops out in the
Churchill Mountains, part of the
Transantarctic Mountains of southwestern Antarctica. The most complete exposures are in the
Holyoake Range. Paleontological data and carbon isotope stratigraphy indicate that the Shackleton Limestone ranges from lower
Atdabanian through upper
Botomian. The formation is a thick carbonate deposit with a lower unit of unfossiliferous interbedded
quartzite and
limestone, overlies the Late Proterozoic
argillaceous turbidite Goldie Formation and underlies the
Starshot Formation. Other
lithologies noted in the Shackleton Limestone are
marble with
breccia,
conglomerate,
sandstone and
shale. The abrupt transition from the Shackleton Limestone to a large-scale, upward coarsening
siliciclastic succession records deepening of the outer platform and then deposition of an eastward-prograding molassic wedge. The various formations of the upper Byrd Group show general stratigraphic and age equivalence, such that coarse-grained
alluvial fan deposits of the
Douglas Conglomerate are proximal equivalents of the marginal-marine to shelf deposits of the Starshot Formation. The sandstone-rich lower member of the Shackleton Limestone is exposed at Cotton Plateau beneath Panorama Point, where it consists of up to of interbedded white- to cream-weathering, vitreous,
quartz sandstone and brown-weathering, white, fine-grained
dolomitic grainstone. These beds are in fault contact with the adjacent Goldie Formation. The formation postdates the
Beardmore Orogeny of the
Neoproterozoic, and was deformed by the
Ross Orogeny. == Fossil content ==