USING FOUNDATIONS FROM THE PAST TO UNRAVEL THE QUATERNARY STRATIGRAPHY BENEATH CLEVELAND, OHIO

Acquiring information about Quaternary stratigraphy in older urban areas is difficult, especially when there is no state requirement to file engineering borehole logs. Therefore, much information about Quaternary stratigraphy is often lost. In 1924, boreholes were drilled for the foundations of Cleveland's Union Terminal (now Tower City) and the Eagle Avenue Bridge. Over 200 samples from these borings, borehole logs, and cross sections were discovered in the archives of Tower City and transferred to Cleveland State University. We determined that these archival materials would provide a wealth of information about the Quaternary stratigraphy beneath downtown Cleveland.

Textural, carbonate, and x-ray diffraction analyses were used to correlate these samples with established stratigraphic units south of Cleveland. Correlation was complicated because engineers collected one "representative" sample from each unit per borehole. Lithologic descriptions, laboratory analyses, and elevation analyses were used to sort the samples into nine units ranging in age from Illinoian to Holocene. Possible Illinoian diamicts overlie shale in the deepest borings, whereas the lithology of most other holes includes thick sequences of Late Wisconsinan fine-grained diamicts and associated glacio-lacustrine deposits overlain by beach deposits of lakes Warren and Wayne. Two AMS dates on the same twig in lacustrine sediments suggest that the ice had melted back from this part of northern Ohio by 14,400 radiocarbon years ago.