GEOGRAPHICAL DISTRIBUTION
In the Western Hemisphere phosphate rock is produced in the United States, in Canada, the Dutch West Indies, and French Guiana, and occurs in Peru and Chile.
United States.
—The principal deposits of phosphate rock in the United States are in Florida, South Carolina, Tennessee, Kentucky, Arkansas, Montana, Idaho, Wyoming, and Utah. Although by far the largest deposits are in the western states, those deposits yield less than 1 per cent. of the whole because of the lack of a large near-by market and because of high freight rates on the crude rock. It is not a matter of common knowledge, but it is, nevertheless, a fact, that the western rock phosphate deposits are so extensive as to be practically inexhaustible, even if the entire world depended on them for its supply of phosphate.
The Florida phosphate deposits, which are the most extensively developed in the United States, comprise three classes of phosphate—hard rock, land pebble, and river pebble. The first is highest grade, the second is produced in largest quantity, and the third is not mined at present. The hard-rock deposits lie in a narrow strip along the western part of the Florida peninsula from Suwanee County to Pasco County, a distance of approximately 100 miles. The land-pebble phosphate area, just east of Tampa, is about 30 miles long and 10 miles wide. Sales of Florida phosphate declined tremendously after 1913 through the restriction on exports by the war. In 1913 the sales were 2,500,000 tons, valued at $9,500,000, and in 1915 the production was 1,350,000 tons, valued at $3,700,000.
South Carolina produces land rock phosphate in the vicinity of Charleston. River-pebble phosphate occurs in the same area but is not mined. Some of the South Carolina output has been exported annually. Sales decreased from 169,000 tons in 1911 to 83,000 in 1915, and the value in the same years from $673,000 to $311,000.
Tennessee deposits of rock phosphate are in the west-central part and extreme northeast corner of the state; the latter have not been mined. Three types are recognized and known by their colors as brown, blue, and white rock; the last has not been mined recently. The brown rock is sold under guarantee of 70 to 80 per cent. tricalcium phosphate; the blue rock varies considerably in its phosphatic content. Sales of Tennessee phosphate in 1914 were 483,000 tons, valued at $1,823,000; by 1915 they had fallen to 390,000 tons, valued at $1,328,000.
Kentucky has been an insignificant producer of phosphate rock in recent years. Arkansas phosphate deposits are in the north-central part of the state. The output is small.
Four western states possess enormous deposits of high-grade rock phosphate, but their output is as yet insignificant, being only 3,000 to 5,000 tons a year. The producing states are Idaho, Utah, and Wyoming. Montana is not a producer, although it contains extensive deposits easy of access and close to rail transportation.
Idaho has an unlimited supply of high-grade phosphate in the southeast part of the state. A small quantity is mined in Bear Lake County. The Utah deposits are east of Great Salt Lake, in the Wasatch and Uintah ranges, and east of Bear Lake. These deposits are extensive, but the rock is leaner than the general run of the Idaho phosphate, averaging nearer 60 per cent. than 80 per cent. tricalcium phosphate. Western Wyoming also is rich in rock phosphate, the deposits being mostly in the Owl Creek, Wind River, Gros Ventre, and Salt River ranges. Some of the beds are thick, carrying 80 per cent. tricalcium phosphate, and extend for many miles. They constitute a reserve supply that may be called inexhaustible. Small local demand for fertilizer and lack of cheap transportation may retard for some years the development of the great and rich western deposits.
An estimate of the quantity of rock phosphate available in the United States was made several years ago and need not be revised to account for that mined in the meantime. It is repeated here:
Reserves of Phosphate Rock in the United States
| Long tons | |
|---|---|
| Florida | 227,000,000 |
| Tennessee | 88,000,000 |
| South Carolina | 9,000,000 |
| Kentucky | 1,000,000 |
| Arkansas | 20,000,000 |
| 345,000,000 | |
| Western States: Montana, Idaho, Utah, and Wyoming | 5,367,082,000 |
| Total | 5,712,082,000 |
Canada.
—The principal phosphatic rock in Canada is apatite, which occurs in workable quantity in two main districts—one in the Province of Ontario, the other in the Province of Quebec. These deposits, which were worked mainly by quarrying, are now practically abandoned. Rock phosphate occurs in a thin bed near Banff, Alberta, but is not used.
South America.
—In Aruba and Curacao, islands of the Dutch West Indies, off the coast of Venezuela, are deposits of phosphate rock, from which a small quantity is mined and shipped to Europe. It is reported that the output in 1914 was about 100,000 tons, averaging 85 to 90 per cent. of calcium phosphate.
In Peru, in the Department of Ica, is a deposit of nodular lime phosphate, which is not used because of a local preference for guano.
A large, rich deposit of phosphate is reported in Chile, about 300 miles north of Valparaiso, but has not been developed as yet.
Phosphate deposits occur on the Island of Salut and on the Connetables, close to the coast of French Guiana. The rock is exported.
Europe.
—The high-grade phosphate deposits of Belgium are exhausted, only low-grade deposits remaining. The rock is found in layers and pockets, and carries between 25 and 65 per cent. of bone phosphate. The production from 1911 to 1913 averaged more than 200,000 tons annually.
The principal deposits in France are in the Somme and Oise basins. The best French deposits are higher grade than the Belgian, as they carry 50 to 80 per cent. of bone phosphate, but they are nearly exhausted, only low-grade material remaining. The production from 1910 to 1914 was about 300,000 tons annually.
Important deposits of phosphate rock in Russia can be divided into the northern, central, and southern groups. The deposits of the southern group were the only ones exploited before the war. Their output was about 25,000 tons a year—very small in comparison with the size of the deposits, which are estimated to contain more than 1,500,000,000 tons. Some of the rock is high grade, carrying as much as 75 per cent. tricalcium phosphate, but the normal grade is about 50 per cent.
The only deposits worked extensively in Spain are apatite veins in the Province of Caceras. After lying idle many years these deposits were reopened and produced 28,000 tons in 1917.
Low-grade phosphate in the form of beds of nodules occurs in England, and in Wales. The production has been slight because the deposits are too small for commercial exploitation.
Africa.
—The principal deposits of phosphate rock in Tunis are the Gafsa fields, in the southern half of the country. There phosphate occurs in beds several feet thick, but only those carrying more than 58 per cent. phosphate of lime are exploited. The deposits can be traced for several hundred miles, and constitute a reserve of hundreds of millions of tons. Tunis now produces more phosphate than any other foreign country, its annual output being between 1,500,000 and 2,000,000 tons, most of which goes to southern Europe.
The deposits of phosphate rock in Algeria are continuations of those in Tunis, the important mining districts being in eastern Algeria. The production is over 500,000 tons a year, and the exported rock carries 58 to 68 per cent. of lime phosphate.
Extensive deposits of phosphate occur in Egypt, near the Red Sea, in thin and irregular beds of the same geologic age (Eocene) as the deposits in Tunis and Algeria. The best deposits average 70 per cent. lime phosphate and the output in 1916 was 125,000 tons. There are mines 20 miles from Port Safalga, and concessions 12 miles inland from Kosseir and also at Sebaia, on the eastern bank of the Nile between Keneh and Assouan. Beds of phosphate are found in other districts on both sides of the Nile valley. Practically all the raw rock phosphate produced contains 65 per cent. or more of tricalcium phosphate and is exported mainly to Japan.
Deposits of phosphate occur 80 to 120 kilometers from the city of Tripoli in beds more than 1 meter thick. These beds probably are a continuation of the phosphate deposits in southern Tunis.
Deposits of phosphate are reported in Morocco 125 kilometers south-southwest of Casa Blanca on the west coast and 70 kilometers from the end of a railroad. These deposits are said to be comparable to the Gafsa field, in Tunis.
It is reported that at Dielor, in Senegal, about the latitude of Cape Verde, the westernmost point on the African coast, there is a phosphate bed which is 2 meters thick to a depth of 64 meters. The rock carries only 50 per cent. tricalcium phosphate, so it is not workable under present conditions, especially in view of the abundant high-grade rock in Algeria and Tunis.
Phosphates have been found in Natal, near Weenen, Ladysmith, and Byrnetown, in the form of phosphatic shales and of nodules. The percentage of tricalcium phosphate in the phosphatic shales is too low for use in making superphosphates; the phosphatic nodules are of higher grade but not abundant enough to be of value.
Asia and Australasia.
—In the government of Uralsk, in southwestern Siberia, bordering on the north end of the Caspian Sea, there is reported to be 600,000,000 tons of phosphate rock. It is said that the greater part of this material carries 17 to 20 per cent. phosphoric acid, which is equivalent to 36 to 43 per cent. tricalcium phosphate. The government of Turgai, which borders Uralsk on the east, is reported to contain 67,000,000 tons of phosphate rock, most of which carries 18 to 19 per cent. phosphoric acid, or about 40 per cent. tricalcium phosphate. The highest-grade material reported is 24 per cent. phosphoric acid, equivalent to about 52 per cent. tricalcium phosphate. All the phosphate therefore is low grade. No production is reported from either of the localities.
Low-grade phosphate rock, in sedimentary beds of considerable extent, and high-grade vein deposits are reported in Palestine, on the east side of the Jordan. The sedimentary deposits occur also on the west side of the Jordan. The known reserves are about 3,500,000 tons. The sedimentary deposits average about 48 per cent. and the vein deposits 77 per cent. tricalcium phosphate. As the vein material is suitable for export, these deposits have been explored by a French company, but available information indicates there has been no output.
Islands in the North Pacific Ocean.
—After the discovery of phosphate rock on Rasa Island, 500 miles east of Formosa, a number of years ago, a Japanese company was formed to exploit the deposits. The rock is rich, carrying 75 per cent. phosphate of lime, and the reserves are estimated at 2,800,000 tons. In 1915 Rasa Island yielded 50,000 tons. A former German supply of phosphate is on Angaur Island, in the Pelew group, east of the southern end of the Philippines. Reserves on this island are estimated at 2,000,000 to 4,000,000 tons of phosphate rock, mostly of high grade. Germany increased the output from 45,000 tons in 1910 to 90,000 tons in 1913. Japan has held this island since October, 1914, and is mining 30,000 tons or more phosphate annually.
Deposits of phosphate, consisting of replacements of dolomitic coralline limestone, and phosphatic guano are reported on several other islands in Oceania, as Baker and Fanning Islands, in Polynesia, and Fais Island, in the West Caroline Islands. It is probable that on other islands there are commercial deposits as yet undiscovered.
Islands in Indian and South Pacific Oceans.
—North of Adelaide, in Australia, are pockety deposits of phosphate; they are without regular stratification and are of varying quality. The annual output has been 4,000 to 6,000 tons for several years. In the Otago district, near Clarendon, New Zealand, beds of phosphate 3 to 12 feet thick rest in pockets in limestone. There has been very little if any production.
On Christmas Island (Straits Settlements), which lies in the Indian Ocean 190 miles south of Java, rock carrying 80 per cent. of bone phosphate is quarried and shipped to Australia and Japan. The deposits seem to be irregular, but are estimated to contain several million tons of rock of very high grade. The island belongs to the government of Singapore. Exploitation of the deposits by the British began in 1900. Exports in 1913 were 150,000 tons.
Phosphate rock of high grade is mined on Ocean Island, in the Gilbert Archipelago, between the Marshall and Solomon Islands, east of New Guinea and north of New Zealand. On this and other so-called coral islands in the equatorial belt which for ages have been sea-bird rookeries, leachings from the guano have impregnated the limestone, forming phosphate rock many feet deep. The deposits on this island are said to be many millions of tons and are among the richest in the world. They have been mined since 1901, and have produced as high as 300,000 tons a year. In 1916 the output was 70,000 tons of rock carrying about 85 per cent. tricalcium phosphate. The island is a British possession.
Another British possession in the Gilbert Archipelago containing phosphate rock is Pleasant Island, which is also known as Nauru, or Ngaru, Island. The deposits are similar to those on Ocean and Christmas Islands, being very high in calcium phosphate and low in iron and alumina. Germany formerly owned this island, but it was taken over by the British in 1917.
Makatea, near Tahiti, in the Society Islands, is estimated to contain 10,000,000 tons of very high-grade phosphate rock, irregularly distributed between reefs and pinnacles of dolomite. The deposits were developed as recently as 1910 and yielded more than 300,000 tons before 1917. Some of the rock carries 85 per cent. lime phosphate. The island is a French possession.