Manakacha Formation

{{short description|Geologic formation in Arizona}}

{{Infobox rockunit

| name = Manakacha Formation

| image = Grand Canyon, from Yavapai Point (6633033753).jpg

| imagesize = 265px

| caption = The Manakacha Formation, sitting on a debris slope of Watahomigi Formation, on top of resistant Redwall Limestone, of the same red color

| period = Pennsylvanian

| age = Upper Pennsylvanian{{rp|33,39}}

| type = Geologic unit

| prilithology = sandstone, siltstone

| otherlithology =

| namedfor =

| region = Colorado Plateau, southwest and south

| coordinates = {{Coord|34|00|N|97|00|W|region:US-OK_type:landmark_source:dewiki}}

| unitof = Supai Group

| overlies = Watahomigi Formation

| underlies = Wescogame Formation

| thickness = {{convert|200|ft|m|0}} max (100–200 ft typical)

| extent = Grand Canyon, Verde Valley, and basement rocks of Mogollon Rim and central & east-northeast Arizona

| area =

| map =

| map_caption =

}}

The (Upper) Late Pennsylvanian Manakacha Formation is a cliff-forming, sandstone, red-orange geologic unit, formed from an addition of eolian sand,{{rp|40}} added to marine transgression deposits, (siltstones, etc.), and found throughout sections of the Grand Canyon. It is one of the lower members of the Supai Group (member two of four major units), with the Supai Group found in other sections of Arizona, especially in the Verde Valley region, or as a basement unit below the Mogollon Rim, just eastwards or part of the basement Supai Group of the southwest & south Colorado Plateau.

The Manakacha Formation was laid down (especially in the Grand Canyon). It consists of up to {{convert|400|ft||sp=us}} of calcareous sandstone and shaly mudstone.{{rp|40}} It represents a time when deposition of aeolian sand became more widespread. The Manakacha was deposited at about the same time as the Weber Sandstone was deposited in northeast Utah in Dinosaur National Monument region, northeast of the Uncompahgre Uplift.{{rp|31}} This was likely during the Atokan and Desmoinesian Ages of the Pennsylvianian.{{cite journal |last1=McKee |first1=E.D. |title=The Supai Group of Grand Canyon |journal=U.S. Geological Survey Professional Paper |date=1982 |volume=1173 |doi=10.3133/pp1173|doi-access=free }}{{rp|4}}