EXPLANATION OF MAPS. 533 



area where Clay Marl I (Krai) and Clay Marl II (K m II) oc- 

 cur, no attempt has been made to differentiate between the areas 

 where the clay is bare and where it is covered by gravel deposits 

 of Pleistocene age. Two areas in which Clay Marl III — a heavy 

 sand bed — occurs, are left uncolored. 



The numbers in Mack near the various clay openings are the 

 locality numbers used in the text of the report. By reference to 

 the index all available data respecting each deposit may be found. 



Plate XII. — The clay deposits near Keyport and Matawan are 

 shown on Plate XII, no attempt being made to differentiate the 

 areas in which the clay is at the surface from those where it is 

 covered more or less thickly by gravel beds or along the streams 

 "by the swamp and salt-marsh deposits. Thus, for example, im- 

 mediately around Keyport the gravel and sand is locally ten to 

 twenty feet thick, and for the most part nothing else is exposed 

 along the stream bluffs. Yet occasional small exposures show 

 that the clay underlies these later deposits, and it would appear 

 as represented on the map if they were removed. 



The figures on the water indicate the depth in feet at mean low 

 tide. The larger figures in black near the various clay pits are 

 locality numbers as used in the text of the report. 



Plate XIII. — This map shows the distribution of the Alloway 

 •clay in the region about Woodstown. Over the areas marked 

 Aca (diagonal yellow lines), older formations occur, the Allo- 

 way clay having been removed by erosion. These older beds are of 

 various kinds, but as the purpose of the map is to show only the 

 distribution of the clay, these are not differentiated. The areas, 

 Ac (dark yellow), show where the clay is bare or only thinly 

 covered to a depth of a few feet. In the areas, Acb (vertical 

 lines), the clay is so deeply buried as to be for the most part com- 

 mercially valueless. The small circles represent outcrops noted, 

 and from those with numbers samples were taken for examination 

 and testing. 



