Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico
Free-air gravity anomalies along portions of 27 shiptracks observed in 1970 during five cruises of the USNS "GEORGE B. KEITHLEY" in the area of the Texas continental shelf and part of the continental slope reveal a continuous linear maximum, bifurcating at the latitude of Baffin Bay, of as...
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ftunivhouston:oai:uh-ir.tdl.org:10657/8643 2023-05-15T15:35:07+02:00 Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico Burnaman, Michael Douglas 1974 application/pdf reformatted digital https://hdl.handle.net/10657/8643 en eng 17554233 https://hdl.handle.net/10657/8643 This item is protected by copyright but is made available here under a claim of fair use (17 U.S.C. §107) for non-profit research and educational purposes. Users of this work assume the responsibility for determining copyright status prior to reusing, publishing, or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires express permission of the copyright holder. Gravity anomalies Texas Continental shelf Mexico Gulf of Thesis Text 1974 ftunivhouston 2022-06-18T22:07:35Z Free-air gravity anomalies along portions of 27 shiptracks observed in 1970 during five cruises of the USNS "GEORGE B. KEITHLEY" in the area of the Texas continental shelf and part of the continental slope reveal a continuous linear maximum, bifurcating at the latitude of Baffin Bay, of as much as +32 mgals which may extend along the entire Texas continental shelf at distances of 40-75 km offshore. An oval positive anomaly of +57 mgals exists offshore Port Isabel, Texas. A regional gravity map, prepared from the "KEITHLEY" data and land Bouguer gravity data available in the literature reveals that a positive Bouguer anomaly similar to the linear free-air maximum offshore is present southwest of Freeport, Texas, while the oval anomaly offshore Port Isabel is shown to extend onshore and is associated with sediment loading on the continental margin by the Rio Grande Delta. A crustal section perpendicular to the coastline in the vicinity of Port O'Conner, Texas, constructed using a two-dimensional gravity model, indicates that the Freeport maximum and the linear shelf maximum may be caused by high density, probably ultramafic intrusions up to 14 km wide within the basement of oceanic crust offshore and the Paleozoic meta-sediments onshore. Magnetic models of the intrusion using an aeromagnetic profile extending southeast from the vicinity of Galveston yield depths and widths for the intrusive similar to those indicated by the gravity model near Port O'Conner, approximately 200 km to the south. Plotting the locations of the gravity maximum along 18 of the shiptracks indicated apparent strike-slip displacement of the intrusive, perpendicular to the coast, of as much as 14 km. Integration of the gravity and magnetic data presented in this thesis with modern examples of extensive ultramafic intrusions and a recently published model for a late Triassic opening of the Gulf of Mexico by sea-floor spreading suggests that the ultramafic intrusions along the Texas coastline may represent a "relict" site of the original ... Thesis Baffin Bay University of Houston Institutional Repository (UHIR) Baffin Bay |
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University of Houston Institutional Repository (UHIR) |
op_collection_id |
ftunivhouston |
language |
English |
topic |
Gravity anomalies Texas Continental shelf Mexico Gulf of |
spellingShingle |
Gravity anomalies Texas Continental shelf Mexico Gulf of Burnaman, Michael Douglas Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico |
topic_facet |
Gravity anomalies Texas Continental shelf Mexico Gulf of |
description |
Free-air gravity anomalies along portions of 27 shiptracks observed in 1970 during five cruises of the USNS "GEORGE B. KEITHLEY" in the area of the Texas continental shelf and part of the continental slope reveal a continuous linear maximum, bifurcating at the latitude of Baffin Bay, of as much as +32 mgals which may extend along the entire Texas continental shelf at distances of 40-75 km offshore. An oval positive anomaly of +57 mgals exists offshore Port Isabel, Texas. A regional gravity map, prepared from the "KEITHLEY" data and land Bouguer gravity data available in the literature reveals that a positive Bouguer anomaly similar to the linear free-air maximum offshore is present southwest of Freeport, Texas, while the oval anomaly offshore Port Isabel is shown to extend onshore and is associated with sediment loading on the continental margin by the Rio Grande Delta. A crustal section perpendicular to the coastline in the vicinity of Port O'Conner, Texas, constructed using a two-dimensional gravity model, indicates that the Freeport maximum and the linear shelf maximum may be caused by high density, probably ultramafic intrusions up to 14 km wide within the basement of oceanic crust offshore and the Paleozoic meta-sediments onshore. Magnetic models of the intrusion using an aeromagnetic profile extending southeast from the vicinity of Galveston yield depths and widths for the intrusive similar to those indicated by the gravity model near Port O'Conner, approximately 200 km to the south. Plotting the locations of the gravity maximum along 18 of the shiptracks indicated apparent strike-slip displacement of the intrusive, perpendicular to the coast, of as much as 14 km. Integration of the gravity and magnetic data presented in this thesis with modern examples of extensive ultramafic intrusions and a recently published model for a late Triassic opening of the Gulf of Mexico by sea-floor spreading suggests that the ultramafic intrusions along the Texas coastline may represent a "relict" site of the original ... |
format |
Thesis |
author |
Burnaman, Michael Douglas |
author_facet |
Burnaman, Michael Douglas |
author_sort |
Burnaman, Michael Douglas |
title |
Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico |
title_short |
Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico |
title_full |
Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico |
title_fullStr |
Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico |
title_full_unstemmed |
Interpretation of regional gravity anomalies on the margin of the northwest Gulf of Mexico |
title_sort |
interpretation of regional gravity anomalies on the margin of the northwest gulf of mexico |
publishDate |
1974 |
url |
https://hdl.handle.net/10657/8643 |
geographic |
Baffin Bay |
geographic_facet |
Baffin Bay |
genre |
Baffin Bay |
genre_facet |
Baffin Bay |
op_relation |
17554233 https://hdl.handle.net/10657/8643 |
op_rights |
This item is protected by copyright but is made available here under a claim of fair use (17 U.S.C. §107) for non-profit research and educational purposes. Users of this work assume the responsibility for determining copyright status prior to reusing, publishing, or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires express permission of the copyright holder. |
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1766365422526922752 |