SOUTHERN PACIFIC LINES 49 
Rosenberg is a commercial center for a large farming and dairy 
district and the junction of several branch railroads. Twenty miles 
south-southwest of Rosenberg is the Boling salt dome, 
Rosenberg. a large uplift which has yielded some oil and contains 
Mesa tt an enormous body of sulphur.*? The town of New 
New Orleans 400 miles. Gulf (population 1,700*) has been established here, 
and the sulphur is bap melted by steam and pinniped 
up to the surface by the Frasch process. (See p. 32.) The deposit 
lies at depths of 450 to 1,200 feet and is believed to contain from 
50,000,000 to 60,000,000 tons of sulphur. Two huge sulphur blocks 
have been made, each 600 feet long, 200 feet wide, and 40 feet high, 
as shown in Plate 6, B, and a still larger one is in progress. The 
material is about 99 per cent pure. The investment at this place is 
said to be $14,000,000. The production in 1930, according to the 
United States Bureau of Mines, was about 750,000 long tons, shipped 
largely to Galveston for water transportation. 
Damon Mound, 20 miles south of Rosenberg, is a prominent 
feature in the flat lowlands, above which it rises 83 feet to an eleva- 
tion of 140 feet. It is due to a typical salt dome in which a steep- 
sided plug of almost pure rock salt is capped by gypsum, anhydrite, 
and limestone. The salt mass penetrates and uplifts Tertiary for- 
mations, which dip away on all sides at steep angles. As in many 
other salt domes, the uplifted strata contained petroleum, most of it 
here being in sandstone and limestone of Oligocene(?) age. Up to 
1924 the production was more than 5,000,000 barrels from 85 wells, 
and in 1930 the yield was 224,000 Lienoks About the mound and 
penetrated by shallow wells are red, blue, brown, and yellow clays of 
the Beaumont formation, apparently deposited around the uplift. 
The salt core, which is of great but unknown thickness, comes within 
about 500 feet of the surface under the heavy cap rock, which is 
present in all domes. It is estimated to contain more than 
1,000,000,000 tons of salt (Bevier). Damon Mound was an impor- 
tant headquarters for the Karankawan Indians, as shown by the 
presence of many fragments of pottery, burial aber stone imple- 
ments, and arrowheads. The Indians regarded the “sour earth” of 
the mound as good medicine, and it had a favorable reputation over 
a wide area. This sour earth is due to the seepage of mineral solu- 
tions, which are usually present about a salt mound. 
® About 58 miles to the south there | the amount having been gradu 
is another large sulphur mine at Big | diminishing since 1926. The first pes 
ill (Gulf), which has been producing | phur mined in Texas was obtained at 
since 1919, and other deposits occur at | Bryan Mound in 1913; now Texas 
Hoskin Mound, Bryan Heights, and | produces 97 per cent of the output of 
Longpoint. The Boling oil field pro- | the United States and 85 per cent or 
duced 378,000 barrels a day in 1930, | more of the world’s output. 
