Page 737 - calmining1890

STANISLAUS COUNTY. 687

Jong the banks of the San Joaquin the blue clay usually overlies a
uicksand, beneath which is a stratum of clay overlying a gravel, which
ields a good supply of potable water.
Near the river on the northern edge of the county, and extending into
?an Joaquin, quicksand is again a prevailing feature of the superficial
itrata, and the following formation has been observed:

of
Thickness
Character of Strata. Strata, in feet,
Sandy soil .? to 4
Quicksand, variable 30 toto 8
''Blue clay 12
Quicksand containing bitter "alkali" water. 4 to 50
Iftlue clay 5 to 10
Gravel* containing good potable water.

In the canons in the western foothills alternate strata of sand and
- loam have been passed through to a depth of about one hundred and
\ twenty-five feet. At that depth a quicksand has been frequently struck
- which yields sufficient water to supply a windmill pump. In many
: instances, in place of putting a false bottom of sand and gravel in the
well, water has been utilized from a'quicksand formation by employing
■ a casing closed at the bottom, with small slits in the side, which
allowed a passage for the water but kept out the quicksand, the casing
- being supported by the strata it penetrated nearer the surface of the
ground.
A well was bored on the ranch of David Hayes, about thirteen miles
northwest from Newman, in a canon in the foothills, and the following
formation was observed:

Character of Strata. Thickness of
Strata, in feet.
Soil 3
; Grayish clay, intercalated with yellow sand, passing into blackish clay 90
From this formation a small amount of fairly good water was struck at
a depth of about forty feet.
Gravish sand .. 160
"Soapy feeling" rock, passing into shale, which became highly fissile and
caved badlv __ . 240

The shale contained a supply of water sufficient for a windmill pump,
but it was biackish and " only fit for watering stock." In the stratum
of shale a seam of coal about two feet thick was bored through, and
several smaller veins only a few inches in thickness. At a depth of a
little over four hundred feet a thin stratum of pebbles was also noticed
which yielded a little water.

IRRIGATION.

There are five different irrigation systems in Stanislaus County, two of
which, namely, the San Joaquin and Kings River, and the San Joaquin
Land and Water Company, are in operation; and three, namely, the
Turlock, the Modesto, and Oakdale irrigating systems, are in process of
construction.