RRS Shackleton S1/76

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Shackleton (74SF)
Cruise identifierS1/76
Cruise period1976-04-01 — 1976-04-26
Port of departureCallao, Peru
Port of returnCallao, Peru
Objectives1. Ocean Bottom Seismograph observations close to the junction of the East Pacific Rise and 9° S Fracture Zone. All previous deployments of the Blacknest OBS have been on the Mid-Atlantic ridge were the half-spreading rate has not exceeded about 1.5cm/year. Near 9° S the East Pacific Rise and the Mid-Atlantic ridge could throw light on the different tectonic processes involved at fast and slow-spreading ridges.
2. An extensive coring programme, supervised by Dr David Cronan of Imperial College. The main aim of the coring programme was to test the hypothesis of the selective dispersion metals from submarine hydrothermal centres. To this end a series of cores were taken along the 9° S fracture zone. Another series of cores was planned for the Bauer Deep, to determine whether these sediments originated on the East Pacific Rise crest and were transported to their present situation or whether they are of local volcanic origin. Finally, a traverse between the East Pacific Rise crest and the South American coast was planned for the benefit of Roy Chester of Liverpool University.
Chief scientistTim J G Francis (Institute of Oceanographic Sciences Wormley Laboratory)
Cruise reportRRS Shackleton S1/76 cruise report shackleton1_76.pdf (0.28 MB) 
Ocean/sea areas 
GeneralSouth East Pacific Ocean (limit 140W)
Track chartsRRS Shackleton S1/76 cruise track — trk1623.html
Geology and geophysics 
Core - rockQuantity: number of cores = 3
Core - soft bottomQuantity: number of cores = 48
Gravity measurementsQuantity: track kilometres = 7408
Magnetic measurementsQuantity: track kilometres = 7408
Other geological/geophysical measurementsQuantity: track kilometres = 7408