The Coconino sun., 1920-02-13
TUBA, ARIZONA AND VICINITY
 TOGETHER WITH INCLUDED RUINS

edge, so to speak, it's entire thickness exceeding 500 feet farther to the northward. Immediately beneath the Navajo sandstones is series of thin bedded sandstones and shale, which is water bearing. The shale often con- tains sandy humps and flattened cal carious mud pebbles. It is exposed only in the canyon walls and is prob ably the todilito formation. Also ex- posed in the canyon walls beneath the shale strata are massive, light red to bright red, cross-bedded sandstone which appears to be of the Wingate formation. The rock of this forma- ton makes fine building stone and was used in making the government building at Tuba. The three forma- tons belong to the LaPlata group of the Jurassic series.
 The Chinlee Formation and the Shinarump Congiomerate are exposel south of Tuba. The former is com posed of shales with thin sandstone and limestone conglomerate, much variegated, and contains much fossil wood, It is a most beautifully color ed formation, often banded when forming bluffs and canyon walls. The colors striking the eye as one travels through the region are sienna, slate, various shades of brown and red, blue, white, black, chocolate, maroon, lilac, drab, purple, gray, pink, rose, ash, gray, lavender and yellow. Truly the region deserves the name Painted Desert" The conglomerate (Shina' lump) series is composed of a gray congl6merate and sandstone, also con taining much fossil, wood. The Shina- trump is probably 60 feet thick; the Chinlee probably 400 feet. The two ] formations belong to the Triassic series.
 Soil-The soil of the oasis and also of Moenkopi wash is of the weathered country rock, limestone and lime ce- mented sandstone, and from dust par ticles from volcanic calcarious and ag- rillaceous rocks blown over the re- zion from the Little Colorado valley by the wind. Alkali is present and is damaging fields both in the wash and in the northeast fields at Tuba. Bur jed organic deposits, including roots and stalks of semi-desert plants, fur nish the organic constituents of the soil. Fine crops are raised in the area annually.
 Water Supply-The Navajo sand stone forming the cap of the kaibito | Plateau is very cross-bedded sand stone, as we have seen. It also con- . tains soft spots which are blown out | by the wind, forming pot-holes, If a horizontal surface, or cliff spaces and caves if along vertical faces. When it rains the potholes fill with water and remain so till the water is evaporated or it seeps through the rock to some underground outlet. And again, the shifting sand piles whole washes full, as it is now filling up Reservoir Can yon, and also pockets large areas in circling dunes, covering parts of the area north of Tuba, which, as a whole, is larger than the state of Con necticut. This bonding of the water also causes it to seep through the rocks to lower outlet through the massive, cross-bedded, porous Navajo sandstone. Reaching the thinner bed ded sandstone and shale, it follows it. Approaching where this shale is near ly or wholly exposed, the water issues from the joints in the sandstone and from the shale exposures ;this has been brought to the surface by abra- sion and weathering and by ex- posing the water bearing horizon by canyon cutting. Through this pro cess, many springs now come to the surface in Reservoir Canyon and at and about the village of Moenkopi and at Moa Ave. Also at Tuba two sets of springs come to the surface, one northwest of the government plat and one northeast of it. The north west springs are now covered over to furnish the water supply for the city, so l could not examine it. The north east springs, several in number, gush forth in sand-elevating, bubbling springs. Both sets raise large vol umes of water to the surface. Each set of these springs has a large dam to impound it's water and hold it for the purpose of irrigation. Two res ervoir dams have also been construct ed in Reservoir Canyon and one large dam in the Moenkopi wash for the same purpose, these also impounding the surface water that descends the washes. A careful husbanding of the water from these sources is now plan