Report on the projected Survey of the State of Maryland. 15 



iron. The forged iron from this ore is commonly found to be hard, 

 and very malleable, and has been used to furnish steel. It was former- 

 ly worked at the furnace known as Ridgely's furnace on the falls of 

 the great gunpowder. 



The whole amount of iron produced annually in the state of Ma- 

 ryland has been estimated at 5800 tons — valued at about $"400,000 ; 

 and it is thought that one half at least of this quantity is derived from 

 the sources which have so far been enumerated. 



From all these considerations, the undersigned are of opinion, that 

 further researches into the mineral constitution of the portion of our 

 state which they have so far passed in review, cannot fail to bring to 

 light new sources of wealth as well as to extend the operation of 

 those that are already known ; whilst they remain persuaded that 

 where so many important interests are subserved, great and lasting 

 benefits must accure to the community at large. 



The undersigned will now proceed to state the results of their ob- 

 servations on other parts of the state. 



The second great division of Maryland, which may be made for 

 the sake of convenience in its geological examination, will embrace 

 that portion of territory lying between the line already defined, 

 as limiting the upper part of the tertiary formation, and another 

 drawn through the state from N. E. to S. W. passing along the sum- 

 mit of Parr's spring ridge, and coinciding nearly with the western 

 limits of Baltimore, Anne Arundel, and Montgomery counties. This 

 division will thus comprise the upper part of Cecil county, the great- 

 est portion of Baltimore and Harford counties, the upper districts of 

 Anne Arundel county, and the whole of Montgomery county. Its 

 geological characters, are that it consists of stratified rocks, varying 

 in mineral composition alternating with each other, and sometimes 

 passing one into another, in such a way as to render it very difficult 

 to affix definite names to their different mixtures. When any of 

 these rocks are viewed singly, they will rarely be found to present a 

 simple mineral substance, constituting a large tract of co'intry. They 

 are, on the contrary, admixtures of several minerals and earths ; the 

 principal of which are, quartz, felspar, mica, hornblende, lime, magne- 

 sia, talc, he. and according to the nature of their aggregation, and the 

 predominance of one or the other, the rocks themselves are described 

 in the systems by different names, is granite, gneiss, mica slate, horn- 

 blende rock, limestone, magnesian limestone, serpentine, steatite 

 (soapstone,) &z.c. These rocks are generally metalliferous, and, as a 

 groupe, are usually called primitive or primary rocks. 



