NW-trending linear gravity and magnetic features: Plate tectonics implications for the western Gulf of Mexico

Conference · Mon Feb 01 00:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:6138457

Heyn, T; Jones, S ^[1]

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1. BP Exploration, Houston, TX (United States)

Gravity and magnetic maps have been interpreted and integrated with geological observations to investigate the linkage between deep sub-salt basement and shallow structures imaged seismically in the Mesozoic-Cenozoic marine section of southeast Texas. Shallow structures could have been inherited from sub-salt basement; e.g. shallow anticlines imaged below a detachment which approximately corresponds with the top of the Wilcox Formation may occur above basement highs. The sub-detachment anticlines probably occur where salt thickness variations mimic the syn-rifting topography. These anticlines formed when autochthonous salt withdrew and the Mesozoic-Cenozoic marine section was draped over sub-salt basement horsts. Salt probably accumulated due to thermal subsidence after rifting, and may partly have infilled some rift basins. Balanced cross-sections indicate that salt withdraw persisted until the Late Oligocene. The interpretation is based on the identification of NW-trending lineaments or alignments of magnetic and gravity anomalies. Lineaments are interpreted as rift-related transfer zones in sub-salt basement because (i) refraction data shot perpendicular to the lineaments indicates that basement relief has a NW -trending alignment, (ii) lineaments parallel the San Marcos Arch, (iii) lineaments occur in the same location on both gravity and magnetic maps, and (iv) transfer zones of Mesozoic graben systems penetrated onshore are NW-trending. NW-trending lineaments do not fan and have a very long radius of curvature; this suggests that the pole of rotation for the early opening of the Gulf of Mexico is located many thousands of kilometers to the northeast or southwest.

• OSTI ID: 6138457
• Report Number(s): CONF-9303212-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 25:1; Conference: 27. annual Geological Society of America (GSA) South-Central Section meeting, Fort Worth, TX (United States), 15-16 Mar 1993; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
GULF OF MEXICO
SALT DEPOSITS
GEOLOGY
DATA ANALYSIS
GEOLOGIC HISTORY
GRAVITY SURVEYS
LINEAMENTS
MAGNETIC SURVEYS
RIFT ZONES
SEISMIC SURVEYS
TEXAS
ATLANTIC OCEAN
CARIBBEAN SEA
DEVELOPED COUNTRIES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
NORTH AMERICA
SEAS
SURFACE WATERS
SURVEYS
USA
580000* - Geosciences