Challenging long-held assumptions of 'erosive-type' convergent margins with 3D seismic imaging offshore Costa Rica
Joel Edwards, UC Santa Cruz
Wednesday, February 20, 2019 at 10:30 AM
- Building 3, Rambo Auditorium
The Costa Rican convergent margin is widely considered an 'erosive-type' convergent margin. Its forearc displays several key proxies thought to be linked to basal erosion, including continental basement extending to near the trench, a record of outer forearc slope subsidence and trench embayment. However, recently collected 3D seismic reflection and drilling data offshore the Osa Peninsula reveal forearc structure and composition that conflicts with the forearc basal erosion model. This talk utilizes these new 3D seismic reflection and drilling data to explore Pleistocene shortening, vertical motion and an in-situ mass budget that challenges the basal erosion model, suggesting that proxies used to characterize convergent margins as erosional may need to be revisited.