NOTE.-Reserve tonnages are calculated from the tonnages shown by the department of taxation for May 1, 1942, adjusted for the amount of ore shipped from May 1 to Dec. 31, 1942; figures include ore in ground and in stockpile. These tonnages constitute proved ore only and do not include the tonnages of concentrate that may be produced from the

taconite or other low-grade material not carried on the tax records at the present time (May 1, 1942). Source of information Minnesota Mines Experimental Station. Jan. 1, 1943, reserves have been adjusted for 1943 and 1944 shipments.

taconite or other low-grade nate ial not carried on the tax records at the present time.
The classification of tonnag ss taken from the records of the department of taxation, as of
May 1, 1942. The tonnage figures shown for concentrates refer not to the tonnages of the
crude ore, but to the estimated onnage of concentrates to be produced from the crude ore.
3 Ore mined by milling is included in open pit direct ore. Ore that has been merely
crushed and screened is included in the direct shipping ore.

No calculated life is shown where the shi ment is either negligible or none.
NOTE.-Estimated life based on annual hipments of 60,000,000 tons and omitting Oliver
reserves approximately 5.82 years.

1 Average 3.585. Average 2.499.

Prior to 1938 information taken from Lake Superior Iron Ore publication of 1938. 1. Yearly ore shipments, p. 309; 2. Base price of ore at lower lakes, p. 322; 3. Railroad rates, P.323; 4. Lake rates, p. 324. Subsequent to 1938, shipments, transportation costs, Lake Erie base prices, taken from Mining Directory of Minnesota. 1944, Great Northern Tariff,

259-q.ICO A-8121.

Lake Superior iron ore shipments total shipments and Minnesota shipments by ranges and beneficiated ores

1 Includes shipments from Fillmore County, Minn.-47 tons in 1941, 59,171 tons in 1942, and 220,427 tons in 1943. Authority: Taken from records compiled by Mines Experimental Station and Lake Superior Iron Ore Association.