Investigating the formation of the Cretaceous Western Interior Seaway using landscape evolution simulations

Ching Chang, Lijun Liu

Research output: Contribution to journalArticlepeer-review


Transient intraplate sedimentation like the widespread Late Cretaceous Western Interior Seaway, traditionally considered a flexural foreland basin of the Sevier orogeny, is now generally accepted to be a result of dynamic topography due to the viscous force from mantle downwelling. However, the relative contributions of flexural versus dynamic subsidence are poorly understood. Furthermore, both the detailed subsidence history and the underlying physical mechanisms remain largely unconstrained. Here, we considered both Sevier orogenic loading and three different dynamic topography models that correspond to different geodynamic configurations. We used forward landscape evolution simulations to investigate the surface manifestations of these tectonic scenarios on the regional sedimentation history. We found that surface processes alone are unable to explain Western Interior Seaway sedimentation in a purely orogenic loading system, and that sedimentation increases readily inland with the additional presence of dynamic subsidence. The findings suggest that dynamic subsidence was crucial to Western Interior Seaway formation and that the dominant control on sediment distribution in the Western Interior Seaway transitioned from flexural to dynamic subsidence during 90–84 Ma, coinciding with the proposed emplacement of the conjugate Shatsky oceanic plateau. Importantly, the sedimentation records require the underlying dynamic subsidence to have been landward migratory, which implies that the underlying mechanism was the regional-scale mantle downwelling induced by the sinking Farallon flat slab underneath the westwardmoving North American plate. The simulated landscape evolution also implies that prominent regional-scale Laramide uplift in the western United States should have occurred no earlier than the latest Cretaceous.

Original languageEnglish (US)
Pages (from-to)347-361
Number of pages15
JournalBulletin of the Geological Society of America
StatePublished - Jun 2020

ASJC Scopus subject areas

  • Geology


Dive into the research topics of 'Investigating the formation of the Cretaceous Western Interior Seaway using landscape evolution simulations'. Together they form a unique fingerprint.

Cite this