384 REPOET OF NATIONAL MUSEUM, 1899. 



4 inches across and of a yellowish-brown color, at Mars Hill, in Mad- 

 ison County. From the oold-bearing sands at Brindleton, Burke 

 County, some 15 tons of sand, containing from 60 to 92 per cent of 

 small crystals, had been obtained prior to 1891. 



According to Mr. H. B. Nitze^ the commercially economical deposits 

 of monazite are those occurring in the placer sands of the streams and 

 adjoining bottoms and in the beach sands along the seashore. The 

 geographical areas over which such workable deposits have been found 

 up to the present time are quite limited in number and extent. In 

 the United States the placer deposits of North and South Carolina 

 stand alone. This area includes between 1,600 and 2,000 square miles, 

 situated in Burke, McDowell, Rutherford, Cleveland, and Polk coun- 

 ties, North Carolina, and the northern part of Spartanburg County, 

 South Carolina. The principal deposits of this region are found along 

 the waters of Silver, South Muddy, and North Muddy creeks, and 

 Henrys and Jacobs Forks of the Catawba River in McDowell and Burke 

 counties; the Second Broad River in McDowell and Rutherford 

 counties; and the First Broad River in Rutherford and Cleveland 

 counties. North Carolina, and Spartanburg County, South Carolina. 

 These streams have their sources in the South Mountains, an eastern 

 outlier of the Blue Ridge. The country rock is granitic biotite 

 gneiss and dioritic hornblende gneiss, intersected nearly at right 

 angles to the schistosity by a parallel system of small auriferous 

 quartz veins, striking about N. 70° E., and dipping steeply to the N.W. 

 Most of the stream deposits of this region have been worked for placer 

 gold. The existence of monazite in commercial quantities here was 

 first established by Mr. W. E. Hidden, in 1879. The thickness of 

 these stream gravel deposits is from 1 to 2 feet, and the width of the 

 mountain streams in which they occur is seldom over 12 feet. The 

 percentage of monazite in the original sand is very variable, from an 

 intinitesimal quantity up to 1 or 2 per cent. The deposits are naturally 

 richer near the headwaters of the streams. 



Brazil. — As above noted, the original source of the Brazilian mo- 

 nazite were gneisses from which the minertil has been liberated by 

 decomposition. The particular localities examined by Professor 

 Derby are in the provinces of Minas Geraes, Rio de Janeiro, and Sao 

 Paulo. The most extensive accumulation thus far reported is in the 

 form of considerable patches on the sea beach near the little town of 

 Alcobaca in the southern part of the province of Bahia, though it 

 has been also found on other sea beaches and in river sands. Nitze 

 writes that 



Sacks filled with this sand were shipped to New York in 1885, the deposit having 

 been taken for tin (.)re. Its true character was, however, soon recognized, and since 

 then a number of tons have been shipped in the natural state, without any further 



1 Sixteenth Annual Report U. S. Geological Survey, 1894-95, pt. 4, p. 



685. 



