ECONOMIC GEOLOGY 475 



both in the interior and along certain portions of the 

 coastal belt (see pp. 398 and 401), but in spite of their 

 wide distribution the deposits are only worked in a few 

 localities. The limestone obtained near Great Fish 

 River Siding in Cradock is well known and is a good 

 example of the tufaceous deposit occurring in the 

 Karroo. The coastal limestones usually contain rather 

 large amounts of sand and are often situated in incon- 

 venient positions. 



Lignite. This substance, which for practical purposes 

 may be considered as an inferior kind of coal, is found 

 in the Uitenhage series and in more recent formations 

 in the Cape Flats and the Knysna district. The pre- 

 sence of lignite in the Uitenhage series has given rise 

 to much prospecting in the Uitenhage, Oudtshoorn, and 

 Mossel Bay Divisions, but the quantity found has in 

 each case been too small. Near Knysna, where lignite 

 occurs in larger quantity than elsewhere in the Colony, 

 an attempt is being made to manufacture briquettes, 

 but the results are not yet known. Lignite has been 

 found at many places under the sand of the Cape Flats, 

 but at present there is no use for it. 



Manganese. Ores of manganese are found at a number 

 of localities in the Western Province and are almost 

 entirely confined to the Table Mountain sandstone. 

 The deposits are found along lines of crush or fracture 

 in the sandstone, and it seems very probable that small 

 quantities of manganese ores are disseminated through 

 the rock and that the mineral has been leached out by 



