30 Cenozoic dynamics of the western North American plate boundary: Insights from offshore marine geology and geophysics into Cordilleran tectonics

We invite presentations on Cenozoic tectonics, volcanism, sedimentation, and geohazards offshore and along the margin of western North America. Example topics include crustal structure, mantle processes, triple-junction migration, paleomagnetism, active faulting, marine stratigraphy, and seismicity.

Friday, 24 April 2026
8:00 AM - 12:00 PM
LMH, Deli

Stratigraphic Development of the Vizcaíno Basin, Late Cretaceous–Cenozoic, Pacific Baja California

Paper number: 30-2
Program: Technical Sessions
Time: 8:25 AM – 8:45 AM

Authors

Abstract

In the Vizcaíno Forearc Basin, more than 5 kilometers of marine sediments accumulated from the Albian to the middle Eocene. These deposits overlie Cretaceous granitic rocks, Aptian and Albian volcanic rocks, and sedimentary units from the Alisitos Arc. The basin contains three major sequences separated by four unconformities: a basal unconformity, an Upper Cretaceous unconformity, a Lower Paleogene unconformity, and a regional Eocene-Miocene angular unconformity. The observed unconformities are as follows:

1- The Pre-Cenomanian Basal unconformity (~110 Ma) underlies Late Albian to Cenomanian conglomerates, and the basin experiences subsidence towards bathyal environments in the Turonian.

2. The Late Cretaceous unconformity (~80 Ma) underlies a late Turonian to  Campanian transgressive cycle, which reached bathyal environments in the Campanian and Maastrichtian.

3. The Lower Paleogene Disconformity (~64 Ma) underlies a third transgressive cycle, which began in the Early Paleocene (~62 Ma) and reached the bathyal environments in the Early Eocene (50 Ma). 

4. The regional angular unconformity from the Eocene to the Miocene (~30 Ma) underlies Neogene and Quaternary deposits in western Baja California.

 

Geological Society of America Abstracts with Programs. Vol. 58, No. 3

doi: 10.1130/abs/2026CD-410816

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