The Markagunt megabreccia: large Miocene gravity slides mantling the northern Markagunt Plateau, southwestern Utah (MP 93-2)

By: J. J. Anderson

The Markagunt Plateau is the southwesternmost of the High Plateaus of Utah, which comprise part of the Colorado Plateaus province. The Markagunt megabreccia, which mantles much of the northern Markagunt Plateau, consists of a structurally chaotic assembles of large masses of the Brian Head, Wah Wah Springs, Isom, Bear Valley, and Mount Dutton Formations. The megabreccia typically consists of house-to city block-sized masses of these rock units, found in any structural attitude in a groundmass of either sheared and folded sedimentary strata of the Brian Head Formation, sheared and shattered sandstone and tuff of the Bear Valley Formation, or unstratified lahar of the Mount Dutton Formation. As well as re-introducing and restricting the Brian Head Formation, this paper also proposes a new unit, the Haycock Mountain Tuff and provides the type section. A reference locality is defined for the Markagunt megabreccia.

Other Information:
Published: 1993
Pages: 37 p.
Location: Beaver County, Carbon County, Emery County, Garfield County, Iron County, Juab County, Kane County, Millard County, Piute County, Sanpete County, Sevier County, Utah County, and Wayne County
Media Type: Paper Map