We use bivariate scatter plots to illustrate variations in selected rock magnetic properties (low‐field susceptibility, anhysteretic and isothermal remanence) of late Neogene and Pleistocene deep‐sea sediments from 16 sites in the Arctic Ocean, North Atlantic, equatorial Atlantic and North Pacific Ocean, and the Arabian Sea. Our intention is to examine the ability of the rock magnetic properties to differentiate the sediments according to factors such as lithology, geographical area, and the dominant mode of terrigenous sedimentation, which at these sites is via ice‐rafting, via bottom currents, or via eolian processes. Overall, correlations between sediment magnetic properties and gross lithology is poor, and factors such as the source and transport path of terrigenous sediment (and detrital magnetic minerals), together with the action of reductive diagenetic processes, are the major controls on the magnetic properties. On the bivariate scatter plots, sites with major ice‐rafted contributions tend to have high sedimentary ferrimagnetic mineral concentrations, relatively coarse ferrimagnetic grain‐sizes, and scattered sample point distributions; in contrast, sites where we infer significant bottom‐current supply of terrigenous material have tightly grouped sample point distributions. Carbonate sediments in which the terrigenous component is supplied by eolian processes tend to have a broad range of magnetic mineral concentration, caused by glacial‐interglacial fluctuations in carbonate accumulation and eolian activity. Sediments containing significant volcanogenic material have high concentrations of relatively coarse‐grained ferrimagnetic material. Reductive diagenesis is a significant determinant of sediment magnetic properties in high‐productivity areas and has the effect of preferentially removing the fine‐grained ferrimagnetic fraction, causing a coarsening of the ferrimagnetic grain‐size distribution and a rise in the antiferromagnetic:ferrimagnetic ratio.

On the Amazon Fan, the meandering Amazon Channel is flanked by levees tens of meters to >100 m high. Grain-size characteristics of the thicker and coarser grained spillover turbidites recovered by coring of the levees can be used to infer the nature of the suspended load and velocity of Pleistocene turbidity currents that transited the channel. Magnetic-mineral alignments in these turbidites provide estimates of flow directions of the overspilling currents. Together, these data augment our understanding of the development and maintenance of large submarine channels. The grain size of spillover turbidites from 10 to 50 m below the seafloor at Ocean Drilling Program Sites 939, 940, 934, 936, 944, and 946 was determined using a Sedigraph 5100 particle-size analyzer. The magnetic alignments were determined by measuring anisotropy of magnetic susceptibility using a Kappabridge KLY-2 susceptibility meter.From the upper to the lower fan, the median size increases and the levee height decreases. Paleoflow during overspill was at a high angle to levee crests, but with considerable dispersion. Paleoflow data can only be properly interpreted in conjunction with information on the local channel shape and the position of low points, or saddles, in the adjacent levee crest. Comparison of (1) the texture of spillover turbidites with (2) grain sizes of sand in the talweg of the Amazon Channel, (3) independent velocity estimates based on differential levee heights, and (4) suspension theory, leads to the conclusion that a single type of mixed-load turbidity current could have transported very coarse sand as bedload along the talweg and contributed to levee growth by spilling a suspension of mainly silt and mud from the flow top. While transiting the Amazon Channel, such turbidity currents were constantly entraining seawater, but were losing a greater volume of dilute suspension from the flow top through overspill. As a result, there is a thirtyfold decrease in channel cross-sectional area from the upper fan to the lower fan. On the lower fan, with levee heights less than 25 m, even some of the sand load from the lower part of turbidity currents was lost to overspill.

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