MAGNETIC VECTOR STUDY IN OIL STATES 15 
of Evangeline, south of Lake Charles, and corresponds with the well 
known structural axis in southern Louisiana along which, besides 
several unproved prospects, lie the domes and oil fields of Jennings, 
Roanoke, Welsh, and Iowa. The indicated “high” south of Lake 
Charles suggests the conclusion which has been drawn from recent 
seismograph work in this area, that the structural axis turns south- 
ward past the Iowa dome and continues south of Lake Charles 
toward the Lockport dome. 
The large negative vectors at DeRidder, Oakdale, and Marble 
Quarry and the horizontal vector at Oberlin suggest a west-east 
magnetic “high” trend south of Oberlin. Due to the large intensity of 
these vectors, it does not seem justifiable to connect them with the 
magnetic “high”’ trend of Lafayette-Lake Charles but it may be con- 
cluded that the magnetic ‘“‘high” or anticlinal structure indicated be- 
tween Ville Platte and Opelousas extends westerly past the Texas 
border. A corresponding gravimetric high trend is indicated by 
torsion-balance work and is usually interpreted as due to a deep 
petrographic or structural regional feature. 
TEXAS! 
REGIONAL STRUCTURE 
Delaware basin.—The magnetic center of the Delaware basin 
seems to lie between Pecos and Barstow. The negative vector at 
Pecos is directed toward the west, and at Barstow, toward the east 
or toward the Central Basin platform, which is indicated by the 
positive vector at Monahans. 
Main Permian basin.—In the southwest part of the main Permian 
basin the negative vectors from Odessa to Big Springs are directed 
toward the southeast, and the negative vectors at Andrews and 
Lamesa toward the northwest, which means that the magnetic axis 
of a basin lies between these two sets of stations. 
The Bend arch.—The Bend arch is indicated by the positive vec- 
tors at Brownwood and neighboring stations, with a north extension 
to Jacksboro. 
Central Mineral region.—The horizontal components of the posi- 
tive vectors at Llano and Burnet and the neutral vector at Lampasas 
all concur at a point half-way between these three stations. This 
1 The local magnetic vectors are based on the information given in “United States 
Magnetic Tables and Magnetic Charts for 1925,” op. cit. 
343 
