Fishtail Mesa
Geology
Fishtail Mesa is a mostly horizontal platform of the cliff-former (and platform-former) Kaibab Limestone, and the Coconino Sandstone also a cliff-former; the rock unit between the two, is the mostly slope-forming Toroweap Formation. Notably, below the Coconino are the slopes of dark-burnt-red Hermit Formation (Hermit Shale), as thick as the Coconino Sandstone, but the obvious colorful slopes standout, as they sit on the Supai Group, and another cliff-former, Supai unit 4 of 4, the extremely hard Esplanade Sandstone. Along the southeast cliffs overlooking Fishtail Canyon, another shelf occurs for Supai unit 2, the Manakacha Formation. So each cliff unit is alternating with a slope former.
The Supai Group sits on the platform of the Redwall Limestone, (a cliff-former, with massive cliffs in East Grand Canyon). Below the Redwall, is a short cliff of Muav Limestone, (but also a platform-former), then the slope-former slopes of Bright Angel Shale.
Fishtail Point
Fishtail Point is located at the southwest terminus of Fishtail Mesa. The point contains two platforms of white cliffs, with the lower Coconino Sandstone cliff, and platform, upon eroded slopes of the Hermit Formation. Most of the dark burnt-brick-red slopes of the Hermit Shale, are covered and obscured, by debris slopes of the Coconino Sandstone.
Biology: Fishtail Mesa as a Relict Biological Site
Fishtail Mesa, as a plateau unaffected by human visitation, and ranching or grazing influences, the plateau has been studied as a relict biological site (1958). In 1996 it was resurveyed to reveal changes in the plant species. The two tree communities are Pinus edulis (Pinõn Pine), and Juniperus osteosperma (Utah juniper); understory species are Artemisia tridentata, (sagebrush), and Poa fendleriana, mutton grass. Torrey joint-fir, Prickly Pear, and Snakeweed also occur.
References
- ^ (elevation 5971 ft), Topozone.com
- ^ Fishtail Mesa, A Vegetation Resurvey of a Relict Area in the Grand Canyon National Park, Arizona, Jstor
- ^ Mountainzone.com
- ^ Fishtail Canyon & Fishtail Mesa photo, Arizona Daily Star
- ^ Fishtail Mesa, A Vegetation Resurvey of a Relict Area in the Grand Canyon National Park, Arizona, Jstor