4 Sedimentary Systems and Provenance in the Western Cordillera

This session invites contributions on sedimentary processes, depositional environments, stratigraphic frameworks, and provenance evolution across western North America. Topics may include basin analysis, source-to-sink studies, and applications of stratigraphy to energy and environmental questions.

Wednesday, 22 April 2026
8:00 AM - 12:00 PM
LMH, Fiesta Terrace Salon

Sepur-Soyaló foreland basin (Late Cretaceous–Paleogene): a sedimentary record of the North American–Caribbean plate collision in Guatemala and Chiapas, Mexico.

Paper number: 4-6
Program: Technical Sessions
Time: 9:40 AM – 10:00 AM

Authors

Abstract

Foreland-basin turbidites accumulated in northern Guatemala and Chiapas during the Late Cretaceous–Paleogene. The deposits are dominated by interbedded sandstone and mudstone, with subordinate conglomerate and limestone. This stratigraphic record documents the collision between the Greater Antilles Arc and the North American passive margin (the Maya block).

In the southernmost part of the Maya Block, northern Guatemala, the turbidites rest on Campanian limestone, where the Globotruncanita calcarata biozone (late Campanian) marks the transition from platform to basin conditions. During the Paleocene, the basin depocenter migrated northward into the Maya Block, reaching central Chiapas. At this stage, turbidites were deposited over Campanian–Maastrichtian limestone and K/Pg breccias.   

To constrain the geologic evolution of the North American–Caribbean collision in Guatemala and Chiapas, we conducted fieldwork, petrographic analysis, and U-Pb detrital zircon geochronology of sandstones from the turbidite successions.

Based on their facies assemblages, the turbidite successions comprise channels, lobes and interlobes, fan fringes, overbank deposits, and slumped and debris-flow elements. Most of the samples analyzed are lithic-rich, containing a higher proportion of lithics fragments relative to quartz and feldspar. Lithic components include limestone, volcanic rocks, serpentinite, and metamorphic rocks. Late Cretaceous turbidite sandstones are characterized by a dominant Cretaceous detrital zircon population and lack pre-Mesozoic ages. Paleocene turbidite sandstones from Guatemala yield mainly Cretaceous, Ordovician–Silurian, Paleocene, and Grenvillian age populations, with minor Permian–Triassic and Ediacaran–Cambrian components. In contrast, Paleocene sandstones from Chiapas are dominated by Grenvillian and Permian–Triassic populations, with subordinate Ediacaran–Cambrian, Ordovician, Cretaceous, and Paleocene ages.        

 

We conclude that Late Cretaceous turbidite deposits of the Sepur–Soyaló foreland basin were sourced from the Greater Antilles Arc, Jamaican magmatism, oceanic floor rocks (forearc ophiolites or proto-Caribbean crust), and Late Cretaceous carbonate platforms. These sediment sources persisted in the Paleocene; however, uplift and exhumation associated with the collision introduced new detrital contributions to the foreland basin. The eastern sector received additional input from the Chuacús Complex and Rabinal Suite, whereas the western sector was fed by the Late Paleozoic Santa Rosa and the Jurassic Todos Santos formations. This contrast suggests two main sediment-dispersal directions during the Paleocene: eastward in the eastern basin sector and northwestward in the western sector.  

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

doi: 10.1130/abs/2026CD-410913

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