The lowland drift consists of the following terraces, in a descending order:
| FEET. | ||
| Soil | 2 to 5 | |
| Gravel and sand with seams of loam, | 40 to 60 | |
| Brick clay with sand and loam, | 20 to 30 | |
| Buried soil with trees, leaves, etc., | 5 to 10 | |
| Gravel and clay, | 5 to 10 | |
| — — | ||
| Total, | 72 115 |
The gravel of the Ohio differs from the Miami in being largely composed of sandstone pebbles instead of limestone.
A formation of local occurrences, known as the blue or Springfield clay, is found in a few places, but in limited, vertical and horizontal, extent. The greatest thickness, of more than 30 feet, is found on north Pearl Street, above Pike.
The broad valley, now occupied in part by Millcreek, extending from the present valley of the Great Miami at Hamilton to the Clifton hills, just north of Cincinnati, separates into two branches, one passing to the north and east of the city, and entering the valley of the Little Miami between Red Bank station and Plainville, while the other branch is the present valley of the Millcreek. There are no rocky barriers (nothing, in fact, but the same drift terraces that make the walls of its present course) to shut out the Great Miami from entering the Ohio valley at the same points where the Little Miami and Millcreek enter. There is every reason to believe that this was once its course.
Another of the earlier courses of the Great Miami, is now occupied by the Dry Fork of the White Water; still a third of the old channels is found near Cleves, Miami Township, where the Miami approaches within one-half mile of the Ohio, but is blocked from entering it by a ridge 150 to 175 feet, composed of glacial drift, and instead makes a circuitous route of 10 miles for an outlet.
The well of Timothy Kirby, in Cumminsville, developed the following borings:
| FEET. | |
| Soil and brick clay, | 12 |
| Sand, | 4 |
| Blue clay with gravel, | 30 |
| Gravel, | 19 |
| Coarse sand, | 3 |
| Sand, with fragments of bituminous coal, | 11 |
| Blue clay with gravel. (Low water of Ohio River.) | 9 |
| Blue clay—fine sand, sprinkled with coal, | 16 |
| Sand, water-worn gravel, blue clay, with occasional fragments of bituminous clay. Shales of blue limestone group, | 43 |
| —– | |
| Total, | 151 |
A remarkable feature of the Millcreek is here presented, of the present bed being at a higher level by 120 feet, than that of the ancient channel,—an erosion that could not have been effected under existing circumstances, but more probable, to the glacial period.