Figure 2. Of the 78 test boring logs, 16 were selected in order to construct a simplified cross section spanning 700 meters. In order to emphasize the elevation changes in the sediment layers, the vertical scale has been exaggerated in comparison to the horizontal scale as shown by the scale bars on the figure. Water depths along the section range from 0 to approximately 49 feet (15 meters). The river bed primarily consists of medium to coarse sand with some gravel, reaching thicknesses up to 46 feet (14 meters).Under the sand unit, silty clay of marine origin reaches thicknesses of as much as 15 meters (49 feet). Beneath the clay and till, Ordovician to Cambrian age (443-545 million year old) bedrock of the Cape Elizabeth Formation was encountered.
Last updated on October 6, 2005