Four corners Power plant has new pollution abatement units added. Post F 20, 1972 p.50 Environmental Protection Agency report in area shows up to 10 times more mercury content than Interior Dept.'s figures. Post Mr 9, 1972 p.39 Mystery of who built the four corners monument. Post Empire Mr 12, 1972 p.46-47,49 Letter to editor gives dates of markers of Four Corners area. Post Empire Ap 2, 1972 p.8