DEEP ELECTRICAL PROSPECTING 75 
Obviously there is no agreement whatever between the electrical 
and well data, either as regards the presence of an oil or gas sand or the 
structural condition. Therefore, it must be concluded that the resis- 
tivity “high” was caused by a lateral change in porosity or mineral 
content of subsurface water at a depth of approximately .4 mile. It 
was reported that the well made considerable fresh water between 
TABLE I 
Rio Ort Corporation’s E. L. ARMSTRONG No. 1 
Jm Hoce County, TExas 
Formation Depth in Feet 
Caliche 20 
Sand and caliche 100 
Sand 125 
Hard shale 150 
Gravel 160 
Hard shale 200 
Sand 205 
Shale 275 
Sand and gravel 290 
Hard shale 380 
Hard sand 402 
Hard cemented gravel 442 
Hard sand gravel 505 
Hard cemented gravel 597 
Hard sand gravel 652 
Hard sand 662 
Hard gravel 682 
Hard shale 700 
Hard sand gravel 732 
Shale 1051 
Sticky shale 1325 
Sandy shale 1425 
Shale 1576 
Sticky shale 1650 
Shale 1700 
Sticky shale 1776 
Sandy shale (cored) ; 1781 
Shale IQ4I 
Sticky shale (cored 1,935-55) 1975 
Sticky shale 2016 
Shale (cored 2,016—36) 2110 
Sticky shale 2186 
Sand (cored) 2223 
Hard sand 2240 
Shale 2269 
Hard sand (cored 2,270-75) 2275 
Sand 2290 
Broken sand 2320 
Shale 2369 
Hard sand rock (cored, 2,369-71) 2375 
Sand (cored) 2382 
Hard sand rock 2384 
Hard sand 2435 
Hard sand rock 4440 
Shale 2460 
Shale and lime (cored) 2468 
Shale 2505 
735 
