Normal vs. reverse fault – the example of curvature's usage on gravimetric data

The gravitational effects caused by normal and reverse faults are very close to each other, both in amplitude and in the shape. We demonstrate the usage of the first curvature as a tool for the setting the slope orientation without the additional geological information. The curvature is calculated not only for the measured data, but for their upward continuation, too. This step helps to lower instability of the curvature computation and is important in the interpretation of the resultant curvature as well. We applied this method on the synthetic test and on the real regional gravimetric data as well. The results show the method could be useful step before the density modelling process and generally during qualitative interpretation in applied gravimetry.

Quantum Crystallography in the Last Decade: Developments and Outlooks

In this review article, we report on the recent progresses in the field of quantum crystallography that has witnessed a massive increase of production coupled with a broadening of the scope in the last decade. It is shown that the early thoughts about extracting quantum mechanical information from crystallographic experiments are becoming reality, although a century after prediction. While in the past the focus was mainly on electron density and related quantities, the attention is now shifting toward determination of wavefunction from experiments, which enables an exhaustive determination of the quantum mechanical functions and properties of a system. Nonetheless, methods based on electron density modelling have evolved and are nowadays able to reconstruct tiny polarizations of core electrons, coupling charge and spin models, or determining the quantum behaviour at extreme conditions. Far from being routine, these experimental and computational results should be regarded with special attention by scientists for the wealth of information on a system that they actually contain.

SITE-DEPENDENT GEOLOGICAL MODEL FOR DENSITY ESTIMATION IN THE NIGER DELTA BASIN, NIGERIA

Seismic and Well-log data covering three wells in tau(τ) Field in the Niger Delta were used for density modelling. Using Hampson Russell Software, Gardner’s and Lindseth’s relations were localized and subsequently transformed to obtain local fits constants for sand and shale lithologies which were used to achieved the final models. The seismic inversion was performed using four steps: well-to-seismic tie, geology model, acoustic impedance inversion and density prediction. A relationship was established between impedance and density. Pairing Gardner with those by Lindseth approaches and also obtained the average, the final models are ρ=0.1572Z_p^0.2126-16997Z_p^(-1)+1.5625 and ρ=0.09045Z_s^0.1935-7093.5Z_s^(-1)+1.4706 for sandstones lithology; ρ=0.3185Z_p^0.3103-6510Z_p^(-1)+1.42855 and ρ=0.16145Z_s^0.2308-34203.5Z_s^(-1)+1.42855 for shale lithology. These models yield a new concept which will contribute to global knowledge. In the absence of density log, these equations can be used to estimate density in the area.