PETROLOGICAL- STATISTICAL APPROACH FOR DIFFERENTIATION AND IDENTIFICATION OF FLUVIO-MARINE ENVIRONMENTS IN THE MLE DELTA, EGYPT

PETROLOGICAL- STATISTICAL APPROACH FOR DIFFERENTIATION

AND IDENTIFICATION OF FLUVIO-MARINE ENVIRONMENTS

IN THE MLE DELTA, EGYPT

By
E. M. DEGHEDY; O. E. FRIHY; M. A. EL ASKARY

AND W. M. MOUFADDAL

*National Institute ojOceanograph.y & Fisheries, Alexandria, Egypt.
Key Words: Petrology, f<1uvio-marine environments, Nile Delta. ABSTRACT Textural and coarse jractivn compositional components are evaluated to distinguish samples from mod~rn environments ofthe ~Nile delta ofEgypt. These environments include: river, coastal dune, accretion ridges, beach, nearshore, lagoon and prodelta. In this study petrologic variables (12 textural and 18 mineralogical, faunal and floral) were considered for each sample. Discrimination was achieved by using simple bar graph ofthe raw data for each environment and Q-mode factor analysis. The factor analysis yielded four compositional assemblages: Factor 1 is dominated by terrigenous fine sand. factor 2 consists of biogenic mud, factor 3 contains terrigenous coarse and medium sands andfactor 4 comprises composite silty sand. Discrimination ofthe seven environments is generally good but less in beach, coastal dune and river sands. Having discriminating the examined environments using Q-mode factor analysis, a graphical model was constructed to determine the origin of "unknown" samples. As a test, this model is satisfactory to identify and interpret the origin of sediments ofHolocene age from two additional cores recovered off the delta coast.