Abstract:
<jats:p>Abstract. The accurate and precise reconstruction of Quaternary
climate as well as the events that punctuate it is an important driver of the study
of lake sediment archives. However, until recently lake sediment-based
palaeoclimate reconstructions have largely concentrated on Northern
Hemisphere lake sequences due to a scarcity of continuous and
high-resolution lake sediment sequences from the Southern Hemisphere,
especially from the southern mid-latitudes. In this context, the deep maar
lakes of the Auckland Volcanic Field of northern New Zealand are significant
as several contain continuous and well-laminated sediment sequences. Onepoto
Basin potentially contains the longest temporal lake sediment record from
the Auckland Volcanic Field (AVF), spanning from Marine Isotope Stage 6e (MIS 6e) to the early Holocene when lacustrine
sedimentation was terminated by marine breach of the south-western crater
tuff ring associated with post-glacial sea-level rise. The Onepoto record
consists of two new, overlapping cores spanning ca. 73 m combined with
archive material in a complete composite stratigraphy. Tephrochronology and
14C dating provide the fundamental chronological framework for the core,
with magnetic relative palaeo-intensity variability downcore, and meteoric
10Be influx into the palaeolake to refine the chronology. The µ-XRF (micro X-ray fluorescence)
downcore variability for the entirety of the lake sediment sequence has
been established with measurement of a range of proxies for climate
currently underway. This work will produce the first continuous record of
the last 200 kyr of palaeoclimate from northern New Zealand to date.
</jats:p>
