Tonto Group

Research output: Chapter in Book/Report/Conference proceedingChapter

5 Scopus citations

Abstract

Facies analyses of the Tonto Group indicate deposition in a variety of fluvial, nearshore, and shallow shelf environments. Braided stream and intertidal-to shallow-subtidal deposits of the Tapeats Sandstone grade seaward into a complex array of shallow shelf sands and muds of the Bright Angel Shale. Shelf sedimentation was influenced by both tidal and storm currents. Sand ridges, sand waves, and broad areas where fine-grained siliciclastics were deposited from suspension settling following storms and during fair-weather periods characterized the shelf. Farther offshore, carbonate islands dotted the shelf. Here, the carbonate buildups were characterized by intertidal and possible supratidal zones separated by deeper water areas where tidal currents were active and where finer-grained carbonate sediments were deposited. A number of transgressions and regressions resulted not only in the intertonguing of the formations of the Tonto Group but also in the vertical juxtaposition of facies belts that probably were not laterally adjacent. -from Authors

Original languageEnglish (US)
Title of host publicationGrand Canyon geology
EditorsS.S. Beus, M. Morales
PublisherOxford University Press/Museum of Northern Arizona Press
Pages83-106
Number of pages24
StatePublished - 1990
Externally publishedYes

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ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this

Middleton, L. T., & Elliott, D. K. (1990). Tonto Group. In S. S. Beus, & M. Morales (Eds.), Grand Canyon geology (pp. 83-106). Oxford University Press/Museum of Northern Arizona Press.