'2 J\oiice3 of the Mineralogy and Geology 



piles of white sand, based on rock, and thinly covered with 

 stinted pine or scrub oak. Through all this region swamps 

 of various extent are found. A kind of geodes of sand 

 stone,* filled with ochres of various colours, is frequently- 

 met with near its upper edge. A crust of sand stone, with 

 a large proportion of iron in it, only a few inches thick, is 

 spread over the surface in some parts of the range called 

 " The high hills of Santee." Of these hills, the site of 

 Columbia affords a good example. This town stands on 

 in elevated plain, the mass of the hill being a very hard 

 orown clay, deposited upon vast quantities (closely com- 

 pacted) of the substance enveloped in the paper marked A, 

 and on huge blocks of granite, now completely decompos- 

 ed, or rather disintegrated. The course of the hill is from 

 N. E. to S. W. The N. W. side is very steep, and quite 

 a heavy clay : the S. E. side slopes off gently in deep sand. 

 In digging wells, rough and hard brown sand stone and 

 pudding stone, with a large proportion of iron, are taken 

 out at great depths. The species of clayf marked A, i? 

 used by Col. Blanding in puddling the reservoir from which 

 he will supply the town with water. It is visible in deep 

 gullies, and from a spot of this sort he has it dug out. 



2. The Clay country is so called because clay predomi- 

 nates. Here, when land is worn out and left uncultivated^ 

 if the slope be considerable, all soil capable of supporting 

 vegetation is washed off, and stiff red clay is left bare. 

 The cultivation of grasses might therefore be useful. Gran- 

 ite is the most common rock, although a large tract of coun- 

 try in this region is formed of argillaceous schistus, (appar- 

 ently a deposit on the primitive rocks,) in all stages of co- 

 hesion, from clay to building stone. The specimens mark- 

 ed B and CJ are from this tract ; and have been used as 



* These are abundant near Colnmbia. I hajipen not to have any just 

 now, but will endeavour to send specimens by another opportunity. Some 

 of tliem are globular, and contain emery. • 



t Thisrlay is plcasin-sly variegated with red spots interspersed in a ground 

 of white; it contains spnns;!es of mica — is a little liarsh at. first, between 

 the fingers, \n\\ iiy riilihinii; becomes somewhat saponaceous to the feel, anri 

 adheres strongly to the tongue. — Editor. 



t B, is consideralily dpcomposod, but bears liie appearance of being B 

 very ^ne grained mica slate, or possibly even an arenaceous quartz: it is 



