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Drove to Otis Mill bluff opposite Chatsworth-
Reading at river level = 1085
"  " [[Ditto for: Reading at]] top of shale in sand = 1115
" [[Ditto for: Reading]] top of silt = 1140
Kansan rises to 1170 [[written over 1165]]
Typical, jointed, darker below, pebbly & a few boulders
12 ft. exposed
On top 4-6 ft. of yellow loess sand seems to run up to about 1140.  There seems to be only a narrow band of silt, but the silt, varying from gray to almost black - is fully 20 feet exposed; it contains fragments of shells even in upper parts, but most of my collection was made from lower part which is dark.
The Kansan has sand boulders in its lower part.
Could not make a clean

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section, but parts were partly close together

[[image-
pencil sketch of Otis Mill Bluff showing geologic strata and sample collection sites]]
[[image captions]]
(Rather too narrow. Expand figure.)
[[at top of hill on left]] Loess 4-6 ft
[[next layer down]] Kansan 12 ft exposed
[[right side of hill half way down]] Sand [[line drawn to a shaded diagonal line]]
[[middle of hill]] Silts X
[[middle bottom of hill]] Shells chiefly Y
[[bottom right of hill]] Belt of oxidized gravels & small boulders -/w 2 ft exposed
[[bottom far right of hill]] Shale
Otis Mill Bluff
So. Dak.
[[/image captions]] 

Took sample of loess & 2 of silts- at X & Y (under sand.)
Blue Shale shows at water & rises above in ledge-
Along road the shale is gray or rusty.  Just exposed? probably naturally so - as far as I could break in.

Transcription Notes:
Chatsworth is a city in Sioux County, Iowa