High-resolution and precisely dated record of weathering and hydrological dynamics recorded by manganese and rare-earth elements in a stalagmite from Central China

Manganese (Mn) and rare-earth elements (REEs) in a stalagmite (SJ3) collected from Central China were analyzed, using an ICP-MS method for the precise determination of > 40 trace elements in geological samples by enriched-isotope internal standardization. Unlike speleothem Mn and REEs investigated by cathodoluminescence, which may be incorporated into crystal lattice, the Mn and REEs analyzed in SJ3 should come largely from colloidal and particle phases in groundwater and may be associated with non-carbonate inclusions. The Mn and REEs in SJ3 vary significantly during the period between 20 and 10 ka. These elements show remarkable increases since ∼ 14.5 ka, suggesting enhanced weathering of the overlying soil layer and the host rock since the onset of the last deglaciation and the strengthening of the Asian summer monsoon. In addition, the Mn and REEs in SJ3 display significant centennial fluctuations which may reflect groundwater dynamics.