brGDGT data from Lake 578, southern Greenland

This dataset includes branched glycerol dialkyl glycerol tetraether (brGDGT) fractional abundances from sediment core, surface sediments, settling particulate matter, and soils of Lake 578 (61.08° N, 45.61° W), southern Greenland. BrGDGTs are lipids thought to be biosynthesized by anaerobic bacteria. These compounds are abundant in lake sediments and potentially can be used as proxies for evaluating past environmental conditions. To improve the application of the brGDGT paleothermometer in high latitudes, we examine brGDGTs distribution from Lake 578, located in southern Greenland. In July 2016, a 70 cm percussion core was collected from Lake 578, and the sediment trap system was deployed. Sediment traps were assembled using a 25.5 cm diameter funnel with a 100 mL centrifuge tube attached at the bottom and allowed to accumulate material for 1 year. Three sediment traps were placed at 5 m, 10 m, and 14 m depths. Each summer (2017, 2018, and 2019) the sediment traps were recovered, the centrifuge tubes exchanged with new ones, and the traps re-deployed at the same location. 5 surface sediment samples were collected with an Ekman grab sampler in July 2018. 13 catchment soil samples were collected from the Lake 578 watershed area. Sediment trap samples, surface sediment samples, and soil samples were frozen until analysis. The sediment core was stored at 4 °C until analysis. All brGDGT samples were analyzed on an Agilent 1260 UHPLC coupled to an Agilent 6120 MSD with the newer methods of Hopmans et al. (2016) to separate the compounds.