Geophysical logs from the Toa Baja scientific drillhole, Puerto Rico

Journal Article · Thu Feb 28 23:00:00 EST 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL00392· OSTI ID:5558728

Anderson, R N ^[1]

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1. Columbia Univ., Palisades, NY (United States)

Geophysical logs from the Toa Baja drillhole on the north central coast of Puerto Rico are used to distinguish the variation in physical properties with depth in this non-volcanic island arc massif. A marked unconformity separates shallow Oligocene to Miocene limestones with considerable permeability contrast from a deeper sequence of volcaniclastic rocks with decreasing shaliness. A volcanic sill or flow overlying a strongly mineralized zone is found to cause the impedance contrast responsible for the strong seismic reflection anomaly (bright spot) that was the exploration target.

• OSTI ID: 5558728
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:3; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

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02 PETROLEUM
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58 GEOSCIENCES
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BOREHOLES
CALIPER LOGGING
CARBONATE ROCKS
CAVITIES
DEPTH
DEVELOPED COUNTRIES
DIMENSIONS
DIPMETER LOGGING
ELECTRIC IMPEDANCE
ELECTRIC LOGGING
EXPLORATORY WELLS
GAMMA LOGGING
GAMMA-GAMMA LOGGING
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOPHYSICAL SURVEYS
GREATER ANTILLES
IGNEOUS ROCKS
IMPEDANCE
ISLANDS
LATIN AMERICA
LIMESTONE
MINERAL RESOURCES
NEUTRON LOGGING
NORTH AMERICA
PERMEABILITY
PETROLEUM DEPOSITS
PHYSICAL PROPERTIES
PUERTO RICO
RADIOACTIVITY LOGGING
RESISTIVITY LOGGING
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SONIC LOGGING
SP LOGGING
SURVEYS
TEMPERATURE LOGGING
USA
VOLCANIC ROCKS
WELL LOGGING
WELLS
WEST INDIES