Problem 12-30 (Algorithmic) (LO. 3) Archie runs a small mineral exploration business (as a sole proprietorship). In 2019, he purchased land (for $84,000) where he suspected a magnesium deposit was located. He incurred $18,000 of exploration costs related to the development of the magnesium mine in 2019 and an additional $26,000 of exploration costs in 2020. Archie elected to deduct these expenditures for regular tax purposes in both 2019 and 2020. In 2021, given a decline in magnesium prices, Archie chose to sell the property for $72,000, rather than bring the mine to production. What AMT adjustments are required in 2021 related to mine exploration expenditures and the sale of the land? As a result, in 2021 a $ 44,000 X negative AMT adjustment is required for mine exploration expenditures and a $ 56,000 X negative AMT adjustment for the sale of the land. Feedback Check My Work It is necessary to determine not only the amount of an adjustment but also whether the adjustment is positive or negative.