The Lowland and Intermediate Upland Section consists of a flat upper terrace surface that is cut by numerous short streams. Most of these stream valleys are narrow and steep sided, but some have wider bottoms and less steep side slopes. The upper terrace surface is underlain by unconsolidated to poorly consolidated sand and gravel. These deposits rest on various metamorphic rocks. The valleys cut through the upper sands and gravels and their slopes are made up of the metamorphic rocks. Local relief is very low in this section and elevations range from sea level to 200 feet. The floodplain of the Delaware River is included in this Section. The northwestern margin of the Section is marked by a change in slope from the relatively flat of this Section to a steeper slope leading to the higher adjacent Piedmont Upland Section. This change in slope is well defined in the southwestern part of this Section, but becomes relatively obscure in the northeastern part of the Section. Here the Section is defined by the occurrence of sands and gravels, flat surface, and continuity with other parts of the section.

The Lowland and Intermediate Upland Section occurs in parts of Delaware, Philadelphia, and Bucks Counties. This area is so urbanized by metropolitan Philadelphia that obtaining a good appreciation of the character of the Section is difficult. Interstate 95 is entirely within the Section from the Pennsylvania-Maryland boundary to just south of its intersection with US Route 1.

The Outstanding Scenic Geological Feature in the Section is Tinicum Marsh.

There are no State Parks or State Forest areas in the Section.