Sample ID: PLUM05WT - 31D Sample Type: Dredge

Cruise information: PLUM05WT Start End Cruise dates 1990-04-18 1990-05-22 Cruise ports Montevideo, Uruguay Recife, Brazil SIO cruise id PLUM05WT Cruise name PLUME LEG 5 Chief scientist Fox, Paul Jeff Cruise narrative This research is designed to test several hypotheses concerning the dynamic processes responsible for creating the spatial and temporal variations in ridge geometry on the slow-intermediate spreading rate ridge system in the South Atlantic from 31-36S. The basic thrust of the experiments is to explore the nature of mantle convection in the vicinity of a spreading center and its role in modifying su rface geometry and morphology of the ridge-transform system. Cruise ngdc number 15040213 Proposal title Mid-Atlantic Ridge Experiment

Sample information PLUM05WT Start End Date 1990-04-29 1990-04-29 Latitude -32.4 -32.4 Longitude -14.292 -14.3 Water depth (m) 3838 3845 SIO code PLUM05WT-31D SIO sample number 31D IGSN number SIO001632 Ship name T. Washington Navigation type SATNAV/GPS-AUTO LOG GYRO+2D DOPPLER SPD Sampling tool type dredge Province ridge crest Crustal age model (mybp) 0.751247

Sub-sample information Sub-sample number 1 Siocode PLUM05WT-31D Depth top (cm) Depth bottom (cm) Lithology Texture Composition Geological age Weight Rock lithology igneous (extrusive/volcanic) - obsidian/quenched basalt-glass Rock min Weathering weathering - moderate Remark some samples exhibit fresh glass Munsell code Exhaust code Comments .5LBS. -GLASS FRAGMENTS AND SHARDS -SOME SAMPLES WITH PALAGONITE COATINGS.