Constraints on the evolution of the East Greenland Margin: Evidence from detrital apatite in offshore sediments

• Main Authors: Clift, Peter D., Carter, Andrew, Hurford, Anthony J.
• Format: Text
• Language: unknown
• Published: LSU Scholarly Repository 1996
• Subjects: East Greenland; Greenland; Iceland
• Online Access: https://repository.lsu.edu/geo_pubs/549; https://doi.org/10.1130/0091-7613(1996)024<1013:COTEOT>2.3.CO;2

We test a new approach to understanding the tectonic evolution of passive margins by using fission-track analysis on detrital apatites from sediments deposited offshore East Greenland. These apatites have not undergone postdepositional track annealing and therefore reflect provenance. The apatites preserve a component of the source rocks' thermal history that otherwise may not be retained within the present-day outcrop. Fission-track-derived denudational histories from samples at Ocean Drilling Program drill sites offshore East Greenland at lat 63°N are compared with data from the onshore Singertat Complex. Previous apatite fission-track studies and geomorphic mapping of the East Greenland coast have shown that locally up to 6 km of denudation may have occurred, implying significant tectonic or magmatic activity starting as much as 30 m.y. after breakup at 56 Ma. In contrast, apatite fission-track data presented here record <2 km of Cenozoic denudation in southeast Greenland, probably driven by magmatic underplating at the time of breakup. Large-magnitude, postrift denudation of East Greenland is restricted to the area around Kangerdlugssuaq (687°N). The timing (<40-50 Ma) and magnitude are in accord with revised plume track models suggesting that the Iceland plume crossed the margin here during the late Eocene.