Extension and transtension in the plate boundary zone of the northeastern Caribbean

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL00394· OSTI ID:5511910

Speed, R C ^[1]; Larue, D K ^[2]

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1. Northwestern Univ., Evanston, IL (United States)
2. Univ. of Puerto Rico, Mayaguez (Puerto Rico)

The authors propose that the Caribbean (Ca)-North American (NA) plate boundary zone (pbz) from the Puerto Rico Trench to the Venezuelan Basin from Mona Canyon east has been in left-transtension over the last 15-20 ma. A boundary-normal component of extension occurs throughout the pbz and is a principal cause of the Puerto Rico Trench. Such extension is due to WNW velocity of NA-Ca and the northward pullaway of NA from its S-dipping slab, which is below Puerto Rico. Strike slip motion may be taken up among terranes in the pbz by rigid CCW rotation and by oblique slip at their boundaries. Rotation of the largest terrane, Puerto Rico-Virgin Islands (PRVI), has caused such major structures as the Muertos thrust and Anegada Passage. The model implies NA-Ca velocity estimated from Cayman transforms is more accurate than that from slip vectors from seisms in the NA slab.

• OSTI ID: 5511910
• 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

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ATLANTIC OCEAN
CARIBBEAN SEA
DEVELOPED COUNTRIES
DEVELOPING COUNTRIES
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GREATER ANTILLES
ISLANDS
LATIN AMERICA
MOTION
NORTH AMERICA
PLATE TECTONICS
PUERTO RICO
ROTATION
SEAS
SLIP
SOUTH AMERICA
SURFACE WATERS
TECTONICS
USA
VENEZUELA
WEST INDIES