Since 1992, extensive oil seeps have been discovered in Cretaceous sediment
and Paleogene basalt onshore central West Greenland. Offshore, the basalts
are buried under younger sediments. Interpretation of seismic data offshor
e has shown the presence of a closed structure at top basalt level. Within
the sediments above the closed structure can be seen bright reflections tha
t have strong AVO (amplitude variation with offset) anomalies. These featur
es may indicate the presence of hydrocarbons that have migrated through the
basalts from deeper source rocks and been trapped in the sediments above t
he basalts.