Spectral library of geological units and determination using hyperspectral CHRIS-Proba images of the southern boundary of the Sivas Tertiary Basin/Turkey

Spectral information about land applications in remote sensing has gained excessively importance. Imaging spectroradiometers contribute to these efforts overwhelmingly and aid to derive geologic information among rocks in semiarid regions. Both field and image processing analyses geologically facilitate this case due to deprived of disturbing any vegetation stress. Sivas and south-eastern prolongations where located on the inner parts of the Anatolian peninsula show this type of region. With this aim, datasets of ESA’s Compact High Resolution Imaging Spectrometer (CHRIS-Proba) have been used to differentiate Jurassic-Cretaceous carbonates, upper Cretaceous ophiolitic mélange rocks and Tertiary deposits in this study.
The region is developed mainly on an oceanic remnant belt called “Inner Tauride Ocean” and has an importance in terms of regional geologic evolution. Carbonates were overthrusted by mélange rocks in the region and younger Tertiary deposits cover unconformably all aforementioned geologic units. A series of noteworthy strike-slip components is significantly observed in Jurassic-Cretaceous carbonates and Tertiary rocks in CHRIS-Proba images based on visual interpretation methods. They are observed in a direction of N 70؛ - 85؛ E. Although fault plane indicators are not observed because of erosional processes, some fault evidents such as calcite veins, fault breccia and systematic joints has been observed clearly. Calcite veins and fault breccia zones approximately from 10 cm up to 2 m, nearly parallel to these strike-slip zones have developed intensively. However, a number of fold axes indicate presence of a polyphased deformation since upper Cretaceous in region. These structural inferences were confirmed with also field studies. In addition to these efforts, a handheld spectroradiometer has been used for taking spectra of the outcropped rock units. Forming a spectral library gathered from those rocks has been started in 2007 summer months based on reliable previous geologic map of the region. Both imaging of CHRIS-Proba sensor and gathering spectra from rocks of the region realized on two different days synchronously. Furthermore, hyperspectral image processing methods such as minimum noise fraction, pixel purity index and spectral angle mapping have been performed to separate ophiolitic rock units. In this study, spectral responses will be evaluated as a result of a function of wavelength and reflection properties of twenty different rock units which were outcropped in study area.