Magnetic anomalies in the West Philippine Basin

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doi: 10.1029/GM019p0253
Author(s): Louden, K. E.
Author Affiliation(s): Primary:
Mass. Inst. Technol., Camb., Mass., United States
Volume Title: Geophysical Monograph
Source: Geophysical Monograph, 19, p.253-267. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0065-8448. ISBN: 978-1-118-66359-2 CODEN: GPMGAD
Note: In English with English summary. Woods Hole Oceanogr. Inst. Contrib. No. 3551; illus. incl. tables, sketch maps
Summary: We present a comprehensive collection of magnetic anomalies in the West Philippine basin together with several bathymetric profiles and nannofossil age dates for DSDP sites 290 and 291. From these data we locate symmetric magnetic anomalies that have strikes roughly parallel to the Central Basin fault. They can be identified as anomalies 17-21 if the basin originated south of the equator and opened at a rate of 41-44 mm/yr. This adds justification but not total proof for the theory that the Central Basin fault may be an extinct spreading center which slowed and then ceased spreading 40 m.y. ago. It is still possible that island-arc spreading created these anomalies, but if so, the origin and evolution of such an arc cannot be simply connected to the later development of the Parece Vela and Shikoku basins to the east. Other results show that the elevation of this region is I km lower than would be observed for similar-aged crust in the North Pacific. If the DSDP dates and our anomaly interpretations are correct, then the lack of a correspondingly large negative gravity anomaly suggests major differences between this extinct ridge and those known to be currently spreading.
Year of Publication: 1976
Research Program: DSDP Deep Sea Drilling Project
Key Words: 18 Geophysics, Solid-Earth; Basins; Cenozoic; Changes; DSDP Site 290; DSDP Site 291; Deep Sea Drilling Project; Direction; Evolution; Faults; Inclination; Interpretation; Island arcs; Leg 31; Lower Tertiary; Magnetic anomalies; Magnetization; Marginal basins; Marginal seas; Models; Movement; North Pacific; Northwest Pacific; Pacific Ocean; Pacific Plate; Paleolatitude; Paleomagnetism; Philippine Basin; Philippine Sea; Plate tectonics; Plates; Remanent magnetization; Reversals; Sea-floor spreading; Spreading centers; Tectonophysics; Tertiary; Transform; West; West Pacific
Coordinates: N174451 N174503 E1332827 E1332804
N124825 N124827 E1274959 E1274951
Record ID: 1977011146
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