2^0 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 25, 



hard rock varies from a few inches up to 18 feet, but when above 

 4 or 5 feet must be regarded as exceptional and local. In some of 

 the lodes generally, and in some parts of all of them, pockets or 

 bunchy deposits of ore either replace the bed of ore (the intervening 

 portions being barren) or are only connected by a few inches of 

 valuable mineral. AYhere bunches are common, horses of ground 

 occur in the gossan, masses of schists or portions of the quartzy vein- 

 stone projecting upwards into the gossan. Very rich deposits have 

 been found where the seam of ore is interrupted by these barren 

 portions of ground, both at the top of the horse and in holes in the 

 hard mundic-rock. The thickness of the ore is often uniform or 

 nearly so for a considerable distance, and in that case varies from 2^ 

 to 4 feet. Not unfrequently the bed of ore thins out and at the 

 same time rises towards one wall of the vein. 



It is almost impossible to determine the quality of the ore from its 

 aspect. It is usually of a dirty black or deep velvet-black colour, 

 moderately hard, but spongy and apparently a good deal decomposed. 

 It is very readily got with the pick, and must all be brought out, as, 

 while underground, there are no means of separating ore from rubbish. 

 Some idea of the varied nature of different parts may be obtained 

 from the following assays of six samples carefully taken by me from 

 different heaps which presented but little difference to the eye. The 

 assays were made by Mr. T. H. Henry, and show a mean of 26*2 per 

 cent, of copper. No. 1 contained 14*9 per cent.; No. 2, 18*6; 

 No. 3, 20-9 ; No. 4, 2M ; No. 5, 28'2 ; and No. 6, 53*4. In the 

 latter there were, no doubt, lumps of black oxide. An analysis having 

 been made by Mr. Henry of an average of these six samples, the re- 

 sult shows : sulphur, 29'47 ; copper, 26*73; iron 26*04; quartz, 8*60 ; 

 oxygen and loss, 9*16. The mineral is therefore a sulphuret of 

 copper and iron with a slight excess of oxide of copper. A certain 

 loss of copper is the result of exposure to the weather or in any way 

 to the action of water. 



The four gossan-lodes I have named respectively Hiwossee, Ten- 

 nessee, Polk County, and Isabella, these being the names of the pro- 

 perties on which they were first opened. The Tennessee is perhaps 

 more properly regarded as a branch of the Hiwassee, but may be 

 described separately. The relative position of the lodes will be seen 

 by reference to the map, fig. 4, p. 247, and the sections, figs. 5 & 6, 

 tty b, c, d. 



The Hiwassee lode ranges nearly N.E. and S.W., dipping S.E. 

 about 15 inches in the fathom. Its gossan is traceable for a mile 

 and a half, commencing on the crest of a hill, and crossing two hills 

 and three valleys. In each valley the width is greatly narrowed and 

 the vein almost lost. The width for about half the length of gossan- 

 outcrop is at least 30 feet. The ore is irregularly distributed, the 

 thickness averaging about three feet, and it lies generally at a 

 moderate depth (ten to twelve fathoms) on the hills, and close to the 

 surface in the valleys. The south-western part of the lode has been 

 much worked from two shafts, and at least 4000 tons of rich ore had 

 been extracted at the date of my visit (1854). 



