Tectonics of the Nazca-Antarctic plate boundary

• Main Authors: Anderson-Fontana, Sandra, Larson, Roger L., Engeln, Joseph F., Lundgren, Paul, Stein, Seth
• Format: Other/Unknown Material
• Language: unknown
• Published: 1987
• Subjects: 46; Antarctic; East Ridge; Fernandez; Antarc*
• Online Access: http://ntrs.nasa.gov/search.jsp?R=19880033467

A new bathymetric chart of part of the Chile transform system is constructed, based mainly on an R/V Endeavor survey from 100 deg W to its intersection with the East Ridge of the Juan Fernandez microplate. A generally continuous lineated trend can be followed through the entire region, with the transform valley being relatively narrow and well-defined from 109 deg W to approximately 104 deg 30 min W. The fracture zone then widens to the east, with at least two probable en echelon offsets to the south at 104 deg and 102 deg W. Six new strike-slip mechanisms along the Chile Transform and one normal fault mechanism near the northern end of the Chile Rise, inverted together with other plate-motion data from the eastern portion of the boundary, produce a new best-fit Euler pole for the Nazca-Antarctic plate pair, providing tighter constraints on the relative plate motions.