Mass-specific susceptibility (chi) with ferromagnetic and combined para- and diamagnetic components from surficial sediment samples from the Bay of Plenty, New Zealand. Measurements were taken on a Princeton Measurements Corporation MicroMag 2900 Alternating Gradient Field Magnetometer (1000 mT loop). This dataset is only used for the para/diamagnetic to ferromagnetic susceptibility ratio, the total susceptibility is more reliably measured on a kappabridge (see additional datasets of this publication).-Lithofacies 1: A fine sand mostly comprised of quartz and feldspars, ca. 2.5% mafic minerals (pyroxene, hornblende,biotite, opaque minerals) and volcanic glass.-Lithofacies 2a: Medium quartz/feldspar sand with ca. 5% mafic minerals and a small amount of volcanic glass.- Lithofacies 2b: Medium sand without volcanic glass.- Lithofacies 3a: Coarse sand, similar in composition to lithofacies 2b with additional rock fragments.- Lithofacies 3b: Coarse to very coarse sand variant of lithofacies 3a.- Lithofacies 4: Medium sand mixture of terrigenous components comparable to lithofacies 2b and bioclastics (shell fragments). - Lithofacies 5: A coarse sand, composed of siliciclastics comparable to lithofacies 3a and biogenic debris derived from bivalves and sponges. Pebble-sized and larger rock fragments are common.- Lithofacies 6: A shell detritus layer covering an unidentified substrate.