Seasonal controls on sediment transport and deposition in Lake Ohau, South Island, New Zealand: Implications for a high-resolution Holocene palaeoclimate reconstruction

• Published in: Sedimentology
• Main Authors: Roop, HA, Dunbar, GB, Levy, R, Vandergoes, MJ, Forrest, AL, Walker, SL, Purdie, J, Upton, P, Whinney, J
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Publishing Ltd 2014
• Subjects: Engineering; Interdisciplinary Engineering; Fluidisation and Fluid Mechanics; New Zealand; Mackenzie Basin
• Online Access: https://doi.org/10.1111/sed.12162; http://ecite.utas.edu.au/97673

Laminated sediments in Lake Ohau, Mackenzie Basin, New Zealand, offera potential high-resolution climate record for the past 17 kyr. Suchrecords are particularly important due to the relative paucity of detailedpalaeoclimate data from the Southern Hemisphere mid-latitudes. Thispaper presents outcomes of a study of the sedimentation processes of thistemperate lake setting. Hydrometeorological, limnological and sedimentologicaldata were collected over a 14 month period between 2011 and2013. These data indicate that seasonality in the hydrometeorological systemin combination with internal lake dynamics drives a distinct seasonalpattern of sediment dispersal and deposition on a basin-wide scale.Sedimentary layers that accumulate proximal to the lake inflow at thenorthern end of the lake form in response to discrete inflow eventsthroughout the year and display an event stratigraphy. In contrast, seasonalchange in the lake system controls accumulation of light (winter)and dark (summer) laminations at the distal end of the lake, resulting inthe preservation of varves. This study documents the key processes influencingsediment deposition throughout Lake Ohau and provides fundamentaldata for generating a high-resolution palaeoclimate record fromthis temperate lake.