8 BULLETIN No. 82^- 



A 



There are three geological epochs represented in the State 

 Archean, Cretaceous, and Neocene. (See Map.) In Kent and Sussex 

 counties the superficial geology is entirely Neocene, while New Castle 

 County has the Archean formation in its northern part, Cretaceous 

 in the central portion, and Neocene in the southern. The Archean for- 

 mation is characterized by the occurrence of gneissic rocks and under- 

 lying crystalline schists ; the Cretaceous belt has beds of clays, shales, 

 and marls ; the Neocene formation is made up for the most part of 

 marls and clays, sands and gravels, and with no underlying or out- 

 cropping rock. 



There is considerable variation in the character of the soil in dif- 

 ferent parts of the State. In the Piedmont section the soil is residual, 

 resulting from the weathering and decomposition of the underlying 

 schists and gneisses, and has been identified by the Bureau of Soils as 

 belonging to the Cecil series. It varies from a silt loam to a stiff clay, 

 and is deep to moderate in depth, and uniformly fertile and well- 

 drained. The soil in the Coastal Plain is a very deep alluvial soil, often 

 with poor underdrainage. In the Cretaceous belt the soil averages 

 heavier than in the Neocene formation, and southward it is increas- 

 ingly sandy. Throughout the whole State the soil is extremely favor- 

 able to rapid tree-growth. 



CLIMATE. 



The climate of Delaware is uniformly mild and equable, and suit- 

 able to a great variety of crops. The following table, taken from re- 

 ports of the Weather bureau for 1906, shows the normal temperature 

 and rainfall for northern, central, and southern Delaware. 



