Code of Federal Regulations Title 26. Internal Revenue § 26.1.615–8 Termination of section 615

(b) Taxable years beginning before January 1, 1970, and ending after December 31, 1969—(1) In general.The termination of section 615 applies to expenditures paid or incurred after December 31, 1969. The income tax treatment of exploration expenditures paid or incurred before January 1, 1970, will be determined in accordance with the provisions of sections 615 and 617 prior to their amendment by the Tax Reform Act of 1969 (83 Stat. 487). The fact that on his income tax return for a taxable year beginning before January 1, 1970, and ending after December 31, 1969, a taxpayer deducts under section 615 expenditures paid or incurred before January 1, 1970, shall not affect his right to deduct under section 617(a) expenditures paid or incurred during such taxable year after December 31, 1969.

(2) Allocation in case of inadequate records.If a taxpayer pays or incurs exploration expenditures during a taxable year beginning before January 1, 1970, and ending after December 31, 1969, but his records are inadequate to permit a determination of the amount paid or incurred during the portion of the year ending after December 31, 1969, and the amount paid or incurred on or before such date, the exploration expenditures as to which the records are inadequate paid or incurred with respect to the mine or property during the taxable year shall be allocated to each part of the year (that is, the part before January 1, 1970, and the part occurring after December 31, 1969) in the same ratio which the number of days in each such part year bears to the number of days in the entire taxable year.