GLOSSARY. 



Granite. Anunstratified rock, composed generally of quartz, 

 feldspar, and mica, and it is usually associated witii the oldest of 

 the stratified rocks. 



Graywackc Grauwacke. A group of strata in the transition of 

 Tv^cks ; but the term has been so iridenniteiy applied, that other 

 names will probably be substituted. 



Greenstone. A trap rock, composed of hornblende and feldspar. 



Grit. A coarse-grained sandstone. 



Gypsum. A mineral, composed of sulphuric acid and lime, 

 and extensively used as a stimulant manure, and for making 

 stucco and piaster casts, &c. It is also called Plaster of Paris. 



H. 



Hornblende. A mineral of a dark green or black colour, and 

 which is a constituent part of greenstone. 



Hornstone. A silicious mineral, approaching to flint in its 

 characters. 



I. 



In Situ. In their original position where they were formed. 

 L. 



Lamincs. The thin layers into which strata are divided, but 

 to which they are not always parallel. 



Lacustrine, Belonging to a lake. Depositions formed in an- 

 cient as well as modern lakes, are called lacustrine deposites. 



Landslip. It is the removal of a portion of land down an in- 

 clined surface, it is in consequence of the presence of water 

 beneath, which either washes away the support of the superin- 

 cumbent mass, or so saturates the materials that they become a 

 slippery paste. 



Line of Bearing, is the direction of the intersection of the 

 planes of the strata with the plane of the horizon. 



Lignite. W ood naturally carbonized and converted into a kind 

 of coal in the earth. 



Littoral. Belonging to the shore. 



Loam. A mixture of sand and clay. 



M. ' 



Mural Escarpment. A rocky cliff, with a face nearly vertical 

 like a wall. 



Mammillary. A surface studded with smooth small segments 

 of spheres like the swell of the breasts. 



Mammoth An extinct species of the elephant. 



Marl. By this term an argillaceous carbonate of lime is 

 usually implied. By custom, its signification is much more ex- 

 tended, and means mineral substances, which act as stimulating 

 or fertilizing manures. There are clay marls, shell marls, and 

 various others. 



