Spectral characteristics, petrography and opaque mineralogy of the Oligo-Miocene basalts at Wadi Abu Qada- Wadi Wata area, west-central Sinai, Egypt

Abstract

The Oligo-Miocene basaltic exposures at Wadi Abu Qada – Wadi Wata area, west-central Sinai Peninsula occur as intra-continental fissure-fed eruptions in the form of km-scale sill attaining thickness of about 30 m and dyke of about 70 m thick, intruding/extruding the Early Cretaceous to Early Eocene sedimentary sequences. Stratigraphy of the study area was dealt with in the context of the geologic setting of these Oligo-Miocene basalts, which are genetically related to the Gulf of Suez rifting in the late Oligocene. These basaltic exposures were discriminated from their surrounding sedimentary rocks using ASTER, Landsat-8 and Sentinel-2 datasets. Spectral characteristics of these basalts were determined by remotely-sensed satellite data as well as by using a handled ASD mineral identifier. Advanced image processing techniques were applied and many images processing algorithms were used in image enhancement including Principal Component Analysis (PCA), Band ratios, Decorrelation Stretch (DS), Mixture Tuned Match Filter (MTMF), and ASTER mineral's indices. All these techniques in conjunction with petrographical investigations were applied in lithological discrimination of the studied Oligo-Miocene basalts and new geological mapping were accomplished and verified by field data. The considered Oligo-Miocene basaltic rocks are mainly olivine dolerite with minor olivine porphyritic basalts. The main mineralogical components are plagioclase, augite and olivine with subordinate Fe-Ti oxides (ferriilmente and titanomagnetite).