Lacustrine (lake) environments provide remarkable archives of climatic and environmental changes in Earth history. The relatively deep and calm waters of lakes collect local precipitation, run-off, sediments carried by run-off, and traces/remains of the biota living in and around them. Over time, deposits accumulate in the lake bottoms that record these environmental conditions.

GRACkLe lacustrine studies focus on collecting lake sedimentary records to reconstruct the local environmental history from older (deeper) to younger (shallower) sedimentary deposits. To get longer, more complete records, we often collect sediment cores to cylindrical tubes of lake-floor sediment extracted vertically from the lake bed (see figure below).

Diagram of a lake basin with multi-colored layers of sediment. A vertical, tall black rectangle overlays the sediments. Lines extending from the top and base of the column indicate an expanded view of the sediment column, demonstrating how a sediment core provides a glimpse of sedimentary layers.
Diagram depicting extraction of lacustrine sediment cores.

From these sediment samples and records, we examine patterns in sedimentation as well as elemental and isotopic information encoded within them.