Abstract This chapter describes a study of the Rotliegend gas field in Germany in which impedance-constrained facies and property models were constructed to reevaluate the field and guide future development. Three-dimensional (3-D) stochastic seismic inversion produces a highresolution acoustic impedance volume by integrating well data with fine vertical sampling and seismic data with dense areal sampling. This acoustic impedance volume can be used as soft data in geostatistical reservoir property modeling. The dense areal sampling in the 3-D seismic grid provides valuable information in interwell areas. Impedance data are particularly useful where well data are sparse.

Evidence from South China and Western Australia for a Late Devonian extraterrestrial impact in the conodont Early crepida Zone (∼365 Ma ago) of the Famennian stage includes microtektites and elemental anomalies (including Ir) in Hunan, South China, and a strong Ir anomaly with a meteoritic Ru/Ir ratio in the Canning Basin, Western Australia. The temporary disappearance of the benthic community coupled with a brachiopod faunal turnover and a drastic change of the carbonate facies in South China, and the coeval “Strangelove Ocean” δ 13 C excursions in both Chinese and Australian sections indicate that at least a regional-scale (possibly global) extinction may have occurred in eastern Gondwana at the time of the impact. The difference in the abundances of Ir between the Canning Basin and Hunan is probably caused by the presence in the former and absence in the latter of the stromatolite Frutexites which may have concentrated the Ir. The presence of microtektites in Hunan is probably due to its more proximal location to the impact site and local diagenetic conditions that allowed the preservation of tektite glass. This Late Devonian impact event is a separate event which postdates the Frasnian/Famennian (F/F) mass extinction by about 1.5 to 2 Ma. If the F/F extinction was also caused by extraterrestrial impacts, it appears that the Late Devonian was a time of closely spaced extraterrestrial impacts which may have triggered at least two extinctions.