In one embodiment, the invention utilizes computer models to calculate predicted spectral estimates that may be encountered during a hydraulic fracturing operation. Seismic events generated by hydraulic fracturing are mapped and displayed upon a graphic user interface. Spectral attributes of selected seismic wave field data from the fracture operation are derived and compared to predicted spectral estimates that match one or more characteristics of the formation. The comparison may be utilized to generate a predicted hydrocarbon content for the fracture zone of the formation and to adjust or alter the hydraulic fracturing operation in order to maximize hydrocarbon recovery.