Phase composition of flood sediments of the German-Polish Odra river immediately after the flood event in 1997

Immediately after the flood event in summer 1997 at the Odra river, samples of flood sediments were taken for a complex phase analysis. The realized i nvestigations show that the sampled flood sediments are very inhomogeneous. The main reasons for this substantial condition are surely different state s of flow during the flood event. It is possible to characterize the investigated material as middle to fine sands with variable phase compositions. The mineral content of the fraction <2 mu m shows a complex composition of amorphous matter, quartz, feldspars , and a different composed clay mineral matter. A high distribution of seve ral mixed layers in the clay mineral phase is detectable. Within the scope of the taken analyses the following minerals were detected: kaolinite (diso rdered), kaolinite/smectite-mixed layer, chlorite/smectite-mixed layer, mon tmorillonite, illite/smectite-mixed layer, celadonite. The investigation of the heavy fraction shows heavy minerals and heavy part icles of different geneses. Mainly these are geogenic, transparent heavy mi nerals like zircon, amphibole, garnet, pyroxene, apatite, rutile, and epido te. Furthermore there were analysed geogenic, opaque heavy minerals (magnet ite and ilmenite), anthropogenic, opaque heavy particles (fly ashes and sla gs), and biogenic components (pyrite framboids). The substantial character of the investigated flood sediments (e.g. content of organic matter, content of clay Minerals) shows that this material is a ble to act as a fixation medium of contaminants.