Age Unit Ft. H.S. 80 70 60 50 40 30 25 20 15 10 5 0 LATE MIDDLE OR EARLY LATE ALBIAN - EARLY CRETACEOUS PATAPSCO FORMATION Description Soil Layer Sandstone: light yellowish grey to brown, epsilon cross- bedded, limonite cemented cap at top. Siltstone: limonite yellow and grey mottled massive. Clay: silty, mottled greenish grey and red, mottled. Sand: white to red mottled, friable, cross-bedded, limonite cemented ledges at top and base; partially covered and possibly slumped. Clay: lenticular, medium grey massive with fossil plants. Siltstone: grey and yellow mottled, massive. Siltstone: grey with red root mottling and red ferruginous staining on bedding surfaces. Siltstone: fining upward to a mudstone; greenish grey with limonite spherules and root mottling. Clay: reddish and greenish mottled, slickensided, intensely red at base, greyer upward. Mudstone: fining upward to a clay; grey, red and brown. Mudstone: yellow, red and brown. Siltstone: yellowish grey and red mottled, spherules and root casts. Mudstone: red and grey mottled, concretions. Interpretation Recent Weathering Channel margin deposit of a shallow laterally migrating stream. Possible distal levee deposit on which soil weathering processes had begun. Flood basin deposit which soil leaching and redeposition had occurred. Channel margin deposit of a shallow, laterally migrating stream. Abandoned channel subject to periodic flooding. Leaching zone (A horizon) of a soil. Zone of accumulation (B horizon) of a subtropical soil developed on a flood plain. Flood plain accretion surface (distal levee) overprinted by soil forming processes. Flood basin deposit on which a gley soil was developed. Gley soil developed on flood basin deposit. Flood basin soil deposit. Distal splay or levee deposit weathering to soil. Flood plain soil. Fig. 5 -- Geologic section of the rocks exposed at the old West Brothers Brick Pit (Stop 3). Section measured by Leo J. Hickey and Norman Frederiksen, 1984. For key to symbols see Fig. 2.