About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 66 (1982)

Issue: 7. (July)

First Page: 983

Last Page: 983

Title: Preliminary Results of Geophysical and Geological Studies to Assess Resource Potential and Geologic Evolution of Central Tonga Ridge and Summit Platform (21-24° Latitude): ABSTRACT

Author(s): D. W. Scholl, T. U Maung, T. V. Vallier, J. Childs, A. J. Stevenson, N. F. Exon, R. H. Herzer, M. W. Sandstrom, S. Soaki

Article Type: Meeting abstract

Abstract:

In April 1982, the R/V S. P. Lee, operated by the USGS, supported geological and geophysical studies over the central area of the Tonga Ridge immediately south of Tongatapu. The cruise plan calls for the collection of approximately 1,250 mi (2,000 km) of multichannel (24) seismic reflection data and several dredge stations to sample submarine outcrops. The bulk (70%) of this work will be concentrated over the summit platform of the ridge, in water depths less than about 5,000 ft (1,500 m). One or more seismic lines will be extended eastward to and slightly seaward of the Tonga Trench, and westward of the ridge's present volcanic axis toward the Lau Basin, in order to resolve the regional rock and structural framework of the ridge. Several multichannel lines will cross the fore-arc basin that lies between the summit platform and the trench. Sonobuoy refraction and wide-angle reflection data will be gathered routinely as well as gravity and magnetic data and high-resolution subbottom seismic records (3.5 kHz and multiplate Uniboom sources). Navigation will be controlled by satellite fixes and computer-generated dead-reckoning positions, based on ship's heading and speed, and doppler-sonar inputs.

The results of the shipboard examination of dredged samples, seismic monitor records, and possibly several hundred km of Previous HitbruteTop-stacked processed multichannel records will be presented at the CPEMRC III. The implications of this sketchy and roughly assembled data base relative to the mineral and petroleum resource potential of the sedimentary sections underlying the ridge's summit platform and the adjacent fore-arc basin will be discussed. Comments on the geologic and tectonic history of the Tonga Ridge implied by the incompletely analyzed field data will be offered for discussion and consideration.

End_of_Article - Last_Page 983------------

Copyright 1997 American Association of Petroleum Geologists