Energy-filtering transmission electron microscopy (EFTEM) and electron energy-loss spectroscopy (EELS) investigation of clay-organic matter aggregates in aquatic sediments

High resolution (< 10 nm) transmission electron microscopy (TEM), energy-filtering TEM (EFTEM), and electron energy loss spectroscopy (EELS) have been used for the direct microstructural imaging and analysis of clay-organic matter aggregates in fine-grained aquatic sediments from Jourdan River Estuary, MS, USA. EFTEM and EELS allow rapid, high-resolution spatial mapping and analysis of light elements such as carbon. The study area sediments are comprised of discrete organic matter masses and aggregates of clay plates. Clay aggregates often include organic matter. The comparison of clay aggregate images obtained by the TEM bright-field technique and the EFTEM carbon mapping technique shows that carbon within clay domains has spatial features that are in the same size scale as the features of individual clay plates within the aggregates (