Preliminary assessment of stratigraphy and structure, San Lucas region, Michoacan and Guerrero States, SW Mexico

Conference · · Mountain Geologist; (United States)

OSTI ID:5617048

Johnson, C A; Cabral-Cano, E; Harrison, C G.A.; Barros, J A ^[1]; Lang, H R ^[2]

---

1. Univ. of Miami, FL (United States)
2. California Inst. of Tech., Pasadena (United States)

Mesozoic marine rocks and Cenozoic continental red beds were mapped at 1:50,000 scale in a 900 km{sup 2} area around San Lucas, in the Balsas River basin between Ciudad Altamirano, Guerrero State, and Huetamo, Michoacan State, Mexico. Interpretation of Landsat Thematic Mapper images, combined with extensive field work, has enabled refinement of the stratigraphy as well as a new interpretation of the structure of the region south of the Mexican Volcanic Belt. A sedimentary sequence nearly seven kilometers thick crops out in the study area. The Mesozoic marine rocks consist of a shallowing-upward sequence approximately 3.5 km thick, with previously unreported laminated cherts at the base, progressing upward through turbidite facies clastic rocks, and shallow water carbonates of middle to Late Cretaceous age at the top. More than three kilometers of continental clastics accumulated above the marine sequence. Continental deposition was interrupted by a major angular unconformity, which is interpreted to record the end of Laramide folding and thrusting. discovery of structural repetitions in the Cretaceous marine sequence has led to reinterpretation of the tectonic evolution of the area. Thin-skinned tectonics played a major role in the structural development of the region during the Laramide orogeny. These conclusions show a lack of compelling evidence for Laramide accretion of tectonostratigraphic terranes in the region.

• OSTI ID: 5617048
• Report Number(s): CONF-8905393--
• Conference Information: Journal Name: Mountain Geologist; (United States) Journal Volume: 28:2-3
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CARBONATE ROCKS
CENOZOIC ERA
CHERT
CRETACEOUS PERIOD
DEPOSITION
DEVELOPING COUNTRIES
DIMENSIONS
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC STRATA
GEOLOGIC STRUCTURES
GEOLOGY
LATIN AMERICA
MAPPING
MESOZOIC ERA
MEXICO
MULTISPECTRAL PHOTOGRAPHY
NORTH AMERICA
OROGENESIS
PHOTOGRAPHY
REMOTE SENSING
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
TECTONICS
THICKNESS
VOLCANIC REGIONS