418 CLAYS AND CLAY INDUSTRY. 



ESSEX COUNTY. 



So far as known, not much clay of commercial value occurs in 

 Essex county, and there are at present no localities where it is 

 dug. The northwest portion of the county lies within the area 

 formerly covered by Lake Passaic, and lacustrine clays of Glacial 

 age are to be looked for in the low areas along the Passaic river, 

 particularly in Caldwell township. If present, they are more or 

 less deeply covered by sand and gravel or by sv* amp muck. Local 

 beds of glacial or alluvial clay probably also occur along many of 

 the streams. 



Clay-working Industry. 



The clay-working industry of this county is of little importance. 

 Common earthenware and some stoneware are manufactured at 

 Newark by the Union Pottery & Drainpipe Works, Excelsior Pot- 

 tery Works and the Belmont Ave. Pottery. 



