ANALYSIS OF AEROMAGNETIC AND BOUGUER GRAVITY MAPS OF THE GULF OF MEXICO

Aeromagnetic intensity and Bouguer gravity anomaly maps of the Gulf of Mexico were created using public domain gravity [DNAG] and magnetic [WDMAM] data. The Bouguer gravity maps indicate the presence of gravity lows just north of the Campeche Escarpment, west of the West Florida Shelf and north of Cuba. The Bouguer gravity lows parallel gravity highs which lie on the Campeche Bank, West Florida Shelf and Cuba. A broad prominent gravity low dominates the western portion of the Gulf while a broad gravity high prevails in the central Gulf. Second derivative Bouguer gravity maps enhance imaging of the edges of these highs and lows, but do not discern any notable structures within them. Directional filtering does not reveal any preferred trend other than the boundaries between the highs and lows. Aeromagnetic maps reduced to the pole reveal a large-amplitude magnetic maximum parallel to the Gulf coastline from the Texas-Mexico border to Lafayette, Louisiana that coincides with a small-amplitude Bouguer gravity maximum. Large-amplitude magnetic highs on the Yucatan Platform contrast with magnetic lows in the central and northern Gulf. The Florida Platform and Cuba consist of high-amplitude magnetic anomalies, corresponding with bathymetric highs. A north-east trending high-amplitude magnetic anomaly parallels the eastern Mexican coast. As with the gravity data, second derivative aeromagnetic maps enhance the edges of these anomalies, but direction filtered maps do not display any distinct lineation other than at the edges of major potential field features. No linear features consistent with proposed sea-floor spreading axes are observed. The lack of potential field fabrics parallel to proposed sea-floor spreading centers in the southern Gulf is inconsistent with previously proposed tectonic models. Particularly of interest are the Bouguer gravity high in the central portion of the Gulf (here termed the Central Gulf Gravity High) and adjacent gravity highs that are separated by relatively narrow gravity lows. We hypothesize that the gravity highs represent fragments of continental crust distributed throughout the Gulf of Mexico. This interpretation contrasts with previous models that suggest broad extension in the northern Gulf and the presence of oceanic crust in the southern Gulf north of Yucatan.