The lithospheric mantle below southern West Greenland: a geothermobarometric approach to diamond potential and mantle stratigraphy.

TY - JOUR

T1 - The lithospheric mantle below southern West Greenland

T2 - a geothermobarometric approach to diamond potential and mantle stratigraphy.

AU - Sand, Karina Krarup

AU - Waight, Tod Earle

AU - Pearson, D. Graham

AU - Nielsen, Troels F.D.

AU - Makovicky, Emil

AU - Hutchison, Mark T.

PY - 2009

Y1 - 2009

N2 - Geothermobarometry of primarily garnet lherzolitic xenoliths from several localities in southern West Greenland is applied to address the diamond potential, pressure and temperature distribution and the stratigraphy of the subcontinental lithospheric mantle ~600 Ma ago. The samples are from kimberlitic and ultramafic lamprophyre (senso lato) dikes and sills emplaced into three tectonically distinct crustal areas in the North Atlantic Craton. Several geothermobarometry formulations have been applied and a thorough assessment of which P-T combinations are most applicable to this sample suite has been conducted. No variation in P-T gradients between the three distinct crustal areas has been discerned. We find that the lithospheric mantle beneath this region extended to a depth of 215 km at the time of eruption, with a geotherm similar to those defined by peridotites from the Slave craton and the Kirkland Lake locality within the Superior craton. In supporting previous studies we find that the continental lithospheric mantle is layered and increases in fertility with depth. Twenty-five of 32 investigated samples are estimated to be derived from the diamond stability field that extends into the reworked Archean North of the Naqssugtoqidian deformation front.

AB - Geothermobarometry of primarily garnet lherzolitic xenoliths from several localities in southern West Greenland is applied to address the diamond potential, pressure and temperature distribution and the stratigraphy of the subcontinental lithospheric mantle ~600 Ma ago. The samples are from kimberlitic and ultramafic lamprophyre (senso lato) dikes and sills emplaced into three tectonically distinct crustal areas in the North Atlantic Craton. Several geothermobarometry formulations have been applied and a thorough assessment of which P-T combinations are most applicable to this sample suite has been conducted. No variation in P-T gradients between the three distinct crustal areas has been discerned. We find that the lithospheric mantle beneath this region extended to a depth of 215 km at the time of eruption, with a geotherm similar to those defined by peridotites from the Slave craton and the Kirkland Lake locality within the Superior craton. In supporting previous studies we find that the continental lithospheric mantle is layered and increases in fertility with depth. Twenty-five of 32 investigated samples are estimated to be derived from the diamond stability field that extends into the reworked Archean North of the Naqssugtoqidian deformation front.

U2 - 10.1016/j.lithos.2009.05.012

DO - 10.1016/j.lithos.2009.05.012

M3 - Journal article

SN - 0024-4937

VL - 112

SP - 1155

EP - 1166

JO - Lithos

JF - Lithos

IS - supplement 2

ER -