Revisiting the Cupidito unit (Cupido Formation) along peritidal carbonates from northeastern Mexico

  • Felipe de Jesús Torres de la Cruz Universidad Autónoma de Nuevo León, Posgrado de la Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.
  • Elizabeth Chacón-Baca Universidad Autónoma de Nuevo León, Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.
  • Gabriel Chávez-Cabello Universidad Autónoma de Nuevo León, Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.
  • María Isabel Hernández-Ocaña, MSc Universidad Autónoma de Nuevo León, Posgrado de la Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.
Keywords: peritidal carbonates, drowning platform, deposition model, sequence boundary, stratiform microbial mats, paleotemperature

Abstract

Depositional episodes are readily identified along representative localities of the Lower Cretaceous Cupido platform in northeastern Mexico. The basal part of the Cupido Formation exhibits a progradational reef platform that, at the upper limit, is truncated by a sequence boundary defined by a breccia. This breccia marks the development of a peculiar sedimentary facies informally known as the Cupidito unit, a distinctive stratigraphical unit in northeastern Mexico that remained uninterpreted for decades. Through the analysis of facies, microfacies and stable isotope comparisons from representative localities (Potrero Chico, Potrero de García, La Huasteca, La Muralla and Puerto Mexico) and from other previously reported outcrops, this work describes six diagnostic features for Cupidito and an improved stratigraphic model is proposed. The depositional sequence suggests a broad flat-topped platform with a general low organic productivity and restricted conditions followed by recurrent inundations of lagoon waters. Before drowning, this carbonate platform remained under equilibrium conditions interrupted by short pulses of relative higher-temperatures (48.3 °C and 39.2 °C). Coral-rudist-stromatoporoid patch-reefs with inferred inter-tropical temperatures between 31.5 °C and 32.2 °C originated as a progradational response to the instauration of a new Sequence Boundary at the base of Cupidito.

Author Biographies

Felipe de Jesús Torres de la Cruz, Universidad Autónoma de Nuevo León, Posgrado de la Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.

PhD candidate at Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León 

Elizabeth Chacón-Baca, Universidad Autónoma de Nuevo León, Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.

Researcher  at Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León

Gabriel Chávez-Cabello, Universidad Autónoma de Nuevo León, Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.

Researcher at Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León 

María Isabel Hernández-Ocaña, MSc, Universidad Autónoma de Nuevo León, Posgrado de la Facultad de Ciencias de la Tierra, Carretera a Cerro 11 Prieto Km 8, Ex. Hacienda de Guadalupe, C.P. 67700, Linares N.L., Mexico.

PhD candidate at Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León 

Published
2020-03-31
Section
Articles