278 FANNING. 
Oil—The greater part of the region is covered by a great 
thickness of fossiliferous, tuffaceous sedimentaries, and the 
structural conditions are favorable to the possibility of oil. 
However, no evidence of its actual presence was seen. During 
the wet season it is said that a heavy film of oil occurs on 
the surface of the water, that seepages in the strata have been 
seen, and that the smell of gas is very distinct. It is said 
that the oil has been so abundant at times as to destroy crops, 
and it is stated that one year burning oil spread over the Bani 
River and was carried to the sea. 
The examination of this region in the dry season revealed no 
trace of oil, and the more recent examination” in the wet season 
also failed to discover any indication. An artesian well, now 
being bored at Alaminos, has reached a depth of over 250 meters, 
but no evidence of oil has been found. 
Cement material.—The great tuffaceous marl deposits around 
Abu and west of Bani contain beds which appear to be well 
adapted to the manufacture of Portland or other hydraulic ce- 
ment. This is shown by the following analyses: 
TABLE IV.—Analyses of cement materials.* 
i- i iat pare? | ah. 
Constituent. 1 2 3 | 4 
| 
Per cent. | Per cent. | Per cent. Per cent. 
Silicat (SiOz) 2 se so se ey RE eae Pe ee | 68. 68 46.13 44.76 0.38 
Alumina) (AlsOs) be eee a See eee | 11. 62 23.13 14, 23 0.18 
Tromoxides(Re203) c.se = oe Se eee oe 5.90 7.51 7.60 | trace 
‘Galcinmoxid ex(Ca@) ass see a ee | 2.85 10.38 15.72 | 55.62 
Magnesia (MgO) 0. 66 3. 65 0.00 
Loss on ignition 13.19 | 13.92) 43.50 
Ratio of SiO2 to Al203+Fe203 -_--______-___________ 3.9 1.5 | 21} 0.2 
a Analyses 1, 2, and 8 by T. Dar Juan, division of general, inorganic and physical chemistry ; 
analysis 4 by Alvin J. Cox. 
b Approximately. 
© Total iron determined as ferric oxide. 
Sample 1 came from sedimentary beds just west of Bani. The 
texture is very fine-grained and no grit can be felt under the 
fingers. The chemical analysis indicates a shale or marl. In 
thin section under the microscope, the rock shows a glassy 
structure, rounded grains of magnetite are abundant, and frag- 
ments of decomposed feldspars are numerous. The rock is tufia- 
ceous in character. 
A free-sand determination gave the following results: 
* Made by Warren D. Smith. 
