Biogeochemical proxy evidence of gradual and muted geolimnological response of Lake Nkunga, Mt. Kenya to climate changes and human influence during the past millennium

•Biogeochemical proxies from a nearshore lake sediment core is used to study sedimentation and paleoclimatic implication in a closed crater lake basin.•A pronounced pluvial period ca. 600 – 500 cal yr. BP is recorded during the little ice age (LIA).•The lake nkunga record indicates that most of the LIA is wet.•The late phase of the LIA to present has a relatively stable and shallow lake Nkunga under dry climate conditions, reflecting the importance of the groundwater recharge it receives from the two springs that are recharged from higher up the mountain.