In January, 1953, arrangements were made for the Geophysical Survey of Middleback Ranges to be extended to the Iron Knob area before completion of the Camel Hills programme. A section extending northerly from, the Monarch-Knob centre was chosen for initial operations and a traverse layout was planned with a northerly extent sufficient to embrace the position of a pronounced Aeromagnetic Anomaly feature. The pegging of the traverses was carried out in advance. The geophysical field work was commended on 6th March and completed on 26th March. Assistance in these operations was shared by Messrs. R. Mattner and R. Ayliffe while H. Ridge and assistant attended to all requirements on the surveying side. As before, the instrument used was the Watts Vertical Force Variometer No. 51840, kindly made available on hire by Enterprise Exploration Co. Pty. Ltd., This report describes the survey results obtained and some interpretation possibilities. The results are shown on Geophysical Plan No. 5, in the form of contour lines representing lines of equal Geomagnetic Vertical Force. The measured profiles are shown on Geophysical Plan No. 5a, sheets 1 to 7.