darton.] MARYLAND. 129 
samples were subsequently obtained down to the depth of 1,052 feet. 
The principal features in the record are as follows : 
Feet. 
0-13 sands and loams with gravels at base. 
13-100 buff and gray sandy clays with shell fragments. 
100-110 dark-gray sandy clay; few shell fragments and small 
pebbles. 
120 gray clay. 
130 gray clay; many shells. 
135 clay, light greenish gray. 
140 clay ; shells and siliceous concretions. 
147 sand, very fine grained ; greenish gray ; glauconitic. 
150 tough clay, light greenish gray. 
160 sandy clay, greenish gray. 
170 clay, lead gray. 
177 glauconitic sands, loose, greenish; shell fragments. 
185 glauconitic sands, loose, greenish; fragments of Perna. 
190 glauconitic sands, moderately coarse; shells. 
230 shells in sand. 
235 sand, dark greenish gray ; shell fragments. 
240 argillaceous sand, gray. 
240-268 clay, greenish gray, with siliceous concretions and lignite 
fragments. 
268-270 siliceous concretion. 
280 clay, dark gray. 
285 clay, tough, greenish gray ; shells. 
290 clay, light greenish, with siliceous concretions. 
310 clay, dark olive; lignite, ferruginous crusts, and shell 
fragments. 
340 clay, light greenish. 
345 sand with shell fragments. 
350-360 argillaceous sand, light green, with fragments of Pecten 
madisonius. 
370 fine sand, greenish gray; fragments of Pecten jeffersonius. 
380-385 clay, greenish gray ; sandy below. 
390-420 sand, light greenish gray, moderately fine. 
420-430 clay, light greenish gray. 
460 clay, very sandy, light greenish gray; shell fragments. 
465 sand, very fine, dark greenish gray, micaceous. 
466-467 sandy clay, dark greenish gray. 
469 clay, dark greenish gray; shell fragments. 
473-480 clay, sandy, greenish gray, lighter below. 
485 clay, bright greenish gray. 
490 sand, fine, greenish gray . 
495-510 clay, light greenish. 
515 clay, very light greenisb tint ; very diatomaceous. 
520-530 similar to 495-510. 
535 clay, light greenish ; diatomaceous. 
545 clay, dark gray. 
555 clay, greenish gray ; diatomaceous. 
565 sand, argillaceous ; shell fragments, Turriiella plebia. 
575 sandy clay, greenish gray. 
585-595 clay, brownish gray. 
600-605 clay, light gray ; diatomaceous ; Anomia. 
610 sand, fine, greenish gray ; shell fragments ; glauconite. 
Bull. 138 9 
