Relationship between the indices of physical and mechanical properties of coal and rock, gas saturation and tectonic dislocation of Donbas

The article deals with the distribution of disturbances in the coal-bearing deposits of Donbas and establishment of the relationship between the indices of physical and mechanical properties of coal and rock, gas saturation and tectonic dislocation. To solve the problems, statistical methods were used (correlation and regression analysis). The schemes of deformations of Donbas have been built, both in individual indices and in indices of complex dislocation, which reflect the regional patterns of distribution of the deformations of various types throughout the Donetsk basin. Close statistical relationship has been established between indices of tectonic dislocation, gas saturation, physical and mechanical properties of coal and rocks, which allows the use of the indices of tectonic dislocation to predict gas content at the regional level.

The sillimanite zones of the Huntly-Portsoy area in the north-east Dalradian, Scotland

SummaryThe distribution of andalusite, kyanite and sillimanite in an important part of the NE Dalradian is mapped. Sillimanite represents a late episode overprinted on the regional Andalusite and Kyanite Zones. The spatial distribution of sillimanite confirms that the heat source for the sillimanite-grade metamorphism in this area was the Newer (or Younger) Basic magma. The sillimanitic aureole of the Newer Basic intrusives is divisible into a Sillimanite Zone and a higher-grade Sillimanite—potash feldspar Zone. Relict andalusite is common in the Sillimanite Zone. Coarse muscovite replacing other minerals is primary in both zones, and should not be confused with late retrograde effects. Electron-probe analytical data on the Sillimanite–potash feldspar zone paragenesis of muscovite are presented. In this, its type area, the so-called ‘Boyne Line’ does not exist; the concept of such a tectonic dislocation arose through misinterpretation of the metamorphic effects.

Note sur la geologie des environs d'Arcy-sur-Cure et de Saint-More (Yonne)

The abrupt change in dip of Rauracian (Jurassic) deposits in the vicinity of Arcy-sur-Cure and Saint-More in Yonne, France, is not due to tectonic dislocation but to differences in the dip of the terminal zone of a Rauracian reef and that of the surrounding marls.