Pre-Maori settlement in New Zealand: evidence from Lake Pupuke sediment record through fecal biomarkers and geochemical approach

Archaeological records suggest that Maori arrived in New Zealand around 700 to 800 cal BP. Their settlement brought tremendous environment and landscape modifications in the island in place for their horticulture and pasture practices. However, Maori oral traditions imply otherwise; suggesting Iwis, different Maori tribes, could have arrived 3 to 4 generations earlier than expected. In this study we present downcore fecal sterol coupled with XRF (Ti) and magnetic susceptibility data, TOC, ?15N and ?13C, in Lake Pupuke, in the North Island of New Zealand spanning 1871 cal yr BP. Fecal sterols (5?-coprostanol + 5?-epicoprostanol) are found in human wastes and are widely used as tracers for prehistoric human presence. Ti and magnetic susceptibility data are used as proxy for terrigenous input and/or erosion. While TOC, ?15N and ?13C could be indicative of changes in carbon source. Downcore coprostanol and epicoprostanol showed peaks at ~700 cal yr BP, which is known to be the Maori arrival. Interestingly, presence of coprostanol and epicoprostanol showed comparable peaks/concentrations at around ~1300 cal yr BP: 500 to 600 years before the known Maori arrival. TOC/CN indicate an overall decreasing trend from 1300 cal yr BP to present, indicative of increasing lake productivity. Magnetic susceptibility and Ti data were constant from 1800 up 700 cal yr BP. Its trend only started to increase just after the coprostanol and epicoprostanol peaks around 700 cal yr BP. The fecal markers peaking at around 1300 cal yr BP could imply early human presence in the area in concurrence to Maori oral traditions. Geochemical data observed in the sediment record indicate different signals in comparison to the pre and known Maori fecal sterol peaks, proposing that the Iwis arrived in the area could have different approaches in terms of landscape and environment modifications.