MARYLAND GEOLOGICAL SURVEY 113 



marine and estuarine animals and land plants. Many localities for these 

 clays are already known and as exploration advances new ones are fre- 

 quently discovered. Some of the more typical exposures will now be 

 described. 



Along the shore, about a mile below Bodkin Point, Anne Arundel 

 County, the variegated clays of the Earitan formation are finely exposed 

 in a cliff some 30 feet in height. These clays occupy the greater portion 

 of the section and carry an abundance of lignite more or less incrusted 

 with crystals of pyrite. Sands and gravels of the Talbot formation un- 

 conformably overlie the clays and constitute the upper portion of the cliff. 

 Half a mile farther south the cliff still maintains its former height, but 

 the section has changed. Some ancient stream must have established its 

 valley on the Raritan, for here the surface of that formation, like a great 

 concave depression, passes gradually beneath the beach to appear again 

 in the cliff 150 yards to the south. In this hollow, lying unconformably 

 on the Earitan formation, is a bed of dark-colored clay about 15 feet 

 thick. Bluish and greenish tinted bands of clay relieve somewhat its 

 somber aspect, and at about its middle portion it carries a bed of peat. 

 But its most striking feature is the presence of huge fossil cypress knees 

 and stumps wliich are imbedded in its lower portion. These stumps 

 vary in diameter from 2 to over 10 feet, and after the removal of the 

 surrounding clay, stand out prominently in the position in which they 

 must have grown. Mr. A. Bibbins, to whom the author is indebted for 

 notes on these deposits, has counted 32 of these stumps which were 

 visible at one time, and also reports finding worm-eaten beechnuts inti- 

 mately associated with cypress cones near the base of the formation. 

 Sands and gravels of the Talbot formation overlie the whole. Imme- 

 diately south of this outcrop the dark-colored clays are temporarily re- 

 placed by the Earitan formation, but they appear again a little farther 

 down the shore, and afford an almost unbroken exposure for about a mile. 

 The thickness of the clay in this locality is at first about 10 or 12 feet, 

 but it gradually becomes thinner southward and finally disappears alto- 

 gether. Casts of Unio shells and not vegetable remains, are its pre- 

 dominant fossils, while, like the beds containing the cypress swamp, it 



