248 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 25, 



the surface. There are also cases in which the blocks of quartz, 

 forming the outcrops of large veins, are replaced or accompanied by 



Figs. 5 & 6. — Sections across the Metamorphic Rocks, showing the 

 Gossan-lodes in the Bucktown Mineral District. 



Fig. 5. — Section from A ^o B ow the Map, fig. 4. 



N.W. 



Hiwassee 

 Lode. 



Fig. 6. — Section from C to J) on the Map, fig. 4. 



Polk County 

 Lode. 



'^v^^^VV'vSMiMteS^^ 



d 



1. Blue slates. 



2. Talcose schists. 



3. Dark ferruginous schists. 



4. Hard schists. 



5. Talcose, steatitic, and garnetiferous 



schists. 



blocks of spongy iron-oxide and hard lumps of magnetic iron-ore. 

 In most cases these veins are nearly vertical, or dip slightly to the 

 south-east. 



Within the narrow belt represented in the map (occupying about 

 four miles in length by one-and-a-half in breadth, or six square 

 miles), there are four very remarkable outcroppings of porous iron- 

 oxide, which together form the subject of the present memoir. Two 

 of them are approximately parallel in the northern, and two others 

 in the southern part of the district. They are of very unequal 

 extension in length of outcrop, and of very unequal width. They are 

 connected more or less distinctly by quartz-strings, of which there 

 are many in addition to those marked in the map. They are occa- 

 sionally accompanied by solid ribs of quartz, forming a foot- or a 

 hanging-wall. They all dip to the south-east, the angle varying in 

 different parts of the same lode. In all of them the surface appear- 

 ance presented by the gossan is that of a mass of cellular iron-oxide, 

 with more or less quartz, forming the walls of the cells, and the pro- 

 portion of peroxide of iron is so large, that under ordinary exposure 

 the mass of outcropping mineral presents a rusty appearance of 

 naked rock with little or no soil, so that its dimensions can be 

 easily and accurately measured. In other cases, where soil is formed 

 upon it, the colour is so deep a vermihon as to mark at once the 

 nature of the underlying rock. 



The exact condition of the rocks enclosing the veins and lodes is 



