HAYES AND 
KENNEDY 
D ] TOPOGRAPHY. 13 
Jefferson County; in Newton and Orange counties, Tex.; and at sev- 
eral points in Calcasieu Parish, La. a 
When the present oil development began it was considered advisa- 
ble to undertake the study of the Coastal Plain in order to bring 
together such geologic information as was available concerning the 
geologic relations of the various deposits and to assist in the eco- 
nomic exploitation of the oil fields. 
With this object in view the Gulf Coastal Plain was thoroughly 
studied. The various deposits of sands, clays, and sandstones were 
examined and compared, their continuity across the country was 
traced, their geologic conditions were studied, and their position in 
the general section of the region was worked out. This has been 
done as far as possible by means of the small bluffs and cuttings seen 
along the courses of the rivers and creeks, as well as of such cuttings 
as could be found along the various railroads traversing the country. 
In addition, the logs of the various deep wells throughout the whole 
Coastal Plain, so far as obtainable, were gathered, and the results of 
the borings collated and compared. 
By these means the general underground conditions of the region 
to a depth of about 2,000 feet have been determined and have been 
described so as to be readily understood by those immediately inter- 
ested in the development of the field. There are, however, many 
questions regarding the underground structure that can not be 
answered until much more drilling has been done. 
TOPOGRAPHY OF THE GULF COASTAL PLAIN. 
That portion of the Gulf Coastal Plain under discussion may briefly 
be described as a belt of country having a width of from 50 to 100 
miles, extending around the shores of the Gulf of Mexico and embra- 
cing in Louisiana, in whole or in part, the parishes of Vermilion, Aca- 
dia, Cameron, Calcasieu, and Vernon; and in Texas the counties of 
Orange, Newton, Jefferson, Hardin, Jasper, Chambers, Liberty, Har- 
ris, Galveston, Brazoria, Matagorda, Fort Bend, Wharton, Jackson, 
Victoria, Calhoun, Refugio, San Patricio, Nueces, Cameron, Hidalgo, 
and portions of AValler, Montgomery, San Jacinto, Polk, and Tyler. 
RELIEF. 
The surface features of the Gulf Coastal Plain are extremely simple. 
In the immediate vicinity of the coast, and for 15 or 20 miles inland 
in the parishes of Vermilion and Cameron and in the counties of 
Orange, Jefferson, Chambers, and Galveston, the general level is 
scarcely more than 3 or 4 feet above the average tides of the Gulf. 
At a few points, such as Grand Chenier and Hackberry Island, in 
Cameron Parish, La., and Big Hill and High Island, in Jefferson and 
"Tenth Census, Vol. X, p. 20, and map, Washington, 1884. 
