Data report: paleomagnetic measurements of igneous rocks from Shatsky Rise Expedition 324

Abstract

Five sites were cored on Shatsky Rise, an oceanic plateau, during Integrated Ocean Drilling Program Expedition 324 to gain a better understanding of its formation processes. To augment and improve the shipboard paleomagnetic results, an additional 135 samples from Sites U1346–U1348 and U1350 were measured at the Northwest Paleomagnetism Laboratory at Western Washington University (USA). Samples from all sites were demagnetized using either alternating field (AF) or thermal demagnetization in approximately equal numbers. Most samples display a downwarddirected overprint likely caused by the drill string magnetic field. This overprint was typically removed by ~10–15 mT AF demagnetization or ~300°C thermal demagnetization. AF demagnetization generally worked well to isolate a characteristic remanence direction, with samples mostly showing low ( 350°–400°C. Some samples showed small sections of self-reversal during thermal demagnetization. Changes in inclination over depth showed little variation at Sites U1346 and U1347, but more variation was recorded at Site U1350. Hysteresis analysis showed that samples from all sites reside in the single-domain to pseudosingle domain region of the Day plot.