The Board approved the recommendation of the Exploration Department 

 and budgeted $2,150,000 for a one-year period of reconnaissance geological 

 and geophysical investigations of the Arenoso Basin. The budget included 

 $100,000 to be used in the acquisition of large blocks of acreage that carried 

 long-lease terms, low bonuses, and cheap rentals. These early lease blocks 

 would be acquired along trends or in areas that appeared most favorably 

 located, based on the meager information available on the basin geology. 



The Exploration Department management then designed a budget con- 

 trolled by the total expenditure approved by the Board (fig. 41-3) and assigned 

 personnel for the exploration program. To supplement the effort without penal- 

 izing other active areas of exploration, contract geophysical crews were utilized 

 in surveying the basin. Key geological and geophysical personnel were taken 

 from active exploration divisions of the company and assigned to this project. 

 A separate organization was formed, acting independent of any division and 

 reporting directly to the exploration management of the company (fig. 41-4). 



During the ensuing year, an intense study was made of the Arenoso Basin. 

 Field geologists utilizing air photos, plane tables, alidades, stadia rods, Brunton 

 compasses, hand lenses, and hammers — the tools of their trade — inspected 

 and mapped most of the outcropping rocks of the area. Large mobile units 

 or trucks carrying personnel and the scientific instruments of the seismograph 

 and the gravity meter traversed the accessible areas of the basin. The total 

 intensity of the earth's magnetic field was mapped by an airborne magnetometer. 

 Mobile drills were utilized to drill shot holes for the seismic units, and larger 

 portable drilling rigs drilled stratigraphic tests in different areas of the basin. 

 Photogeologists studied the air photos of the area, assisted the field geologists, 

 and searched for anomalous patterns in the alluvial cover that might be sugges- 

 tive of structure at depth. Specialists, including a petrographer, a paleontolo- 

 gist, and a structural geologist from the Geologic Research group, assisted the 

 surface and subsurface geologists in accumulating and interpreting their basic 

 data. The Civil Engineering Section, utilizing the services of contract agencies 

 where necessary, began constructing base maps of the area. Landmen acquired 

 leases from many of the large landowners, applications were filed for federal 

 acreage, and titlemen examined the land ownership titles in the courthouses. 

 The vanguard of the oil industry had invaded the Arenoso Basin! 



In initiating this stage of exploration, the management of Amprex's ex- 

 ploration group decided on a program of slim-hole stratigraphic tests. There 

 were several reasons for this immediate drilling program. First, with a large 

 area to explore, it was important that the early exploration energy be devoted to 

 areas with the more attractive sedimentary sections. Second, the seismologists 

 stated that the seismic survey costs would be abnormally high. Based on an 



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