The distribution of major and minor elements in 41 samples from the ferromanganese deposits of the Umm Bogma region, west central Sinai has been investigated and the results obtained were statistically analyzed. The studied ore deposits are observed to be enriched in Pb, Cu, Zn and Ba and depleted of Co, Ni, Be, Mo, Sr and Sn. A strikingly negative correlation is found between MnO2 and Fe2O3. The components K2O, Al2O3, MgO, Cu, Co, Zn, Sr and Sn are positively correlated with Mn and negatively correlated with Fe. On the other hand, SiO2, Be and Mo show positive correlation with Fe and negative correlation with Mn.
R-mode factor analysis extracted a five-factor model, that could explain ca 77% of the total variance in the data. F1 is interpreted as a separation factor between the Fe and the Mn minerals. F2 and F3 reflect the association of some trace elements (Cu, Co, Ni, Pb, Zn, Sn and Sr) with Mn minerals. F4 is a dolomite factor (CaO and MgO) referring to the unreplaced remnants of the original country rocks. F5 reflects the dispersion of Ba in both ore minerals and country rocks. Comparison of the chemical composition of these deposits with that of ferromanganese deposits occurring in various present day environments indicates that hydrothermal activity is mainly responsible for their formation.