[2 Parts] Technical Letter Numbers 53 and 54: Geophysical Investigations in the Bi'r Idimah - Wadi Wassat Area, Saudi Arabia, Part One and Part Two

Report issued in two parts, staple-bound in green and brown printed wraps 22x28cm. Part One, prepared 5 March, issued 2 April 1966: (1)pp covering letter from Glen Brown to Fadil Kabbani, Deputy Minister for Mineral Resources, 4pp text, with 5 loose folding figures in pocket (all present as called for). Wraps fair, re-stapled, with chip to the front (not affecting titles), interiors fine with short closed tears to a couple of figures. Part Two, prepared 20 April, issued 25 April 1966: (1)pp covering letter as above, 3pp text, with 7 folding figures in pocket (all present as called for). Wraps good, re-stapled with short closed tears. Interiors near fine with Fig 3 slightly misfolded. These form a very early "preliminary" product of the monumental USGS-Aramco mapping project (1956-63), which, among other things, produced 21 Geological maps covering the whole of Saudi Arabia in a series of Quadrangles numbered I-200A to I-220A. They were prepared under the follow-up Saudi Arabian Mineral Exploration Project launched in 1963, which Brown coordinated from Jeddah. The work took place within the area covered by Map I-217A (Asir Quadrangle) in December 1965 (Part One) and February 1966 (Part Two). The objective was to conduct electromagnetic tests on a deposit of massive sulphides found during exploratory digging, to locate the richest parts for further test drilling. The figures on the folding sheets, prepared as copies of ms, include location maps and dip-angle profiles. Very rare. Brown's covering letters state 10 copies of each were sent to Kabbani. Additional copies would have been circulated within USGS and probably Aramco. Worldcat locates one copy of each at the Colorado School of Mines (individually listed as OCLC 180775807 and 180775809). USGS reissued them in 1969 as Open-File Reports 69-5 and 69-6 (USGS website).…