A constrained 2D gravity model of the Sebastián Vizcaíno Basin, Baja California Sur, Mexico

The subsurface geometry of the Sebastián Vizcaíno Basin is obtained from the 2D inversion of gravity data, constrained by a density-versus-depth relationship derived from an oil exploration deep hole. The basin accumulated a thick pile of marine sediments that evolved in the fore-arc region of the compressive margin prevalent along western North America during Mesozoic and Tertiary times. Our interpretation indicates that the sedimentary infill in the Sebastián Vizcaíno Basin reaches a maximum thickness of about 4 km at the centre of a relatively symmetric basin. At the location of the Suaro-1 hole, the depth to the basement derived from this work agrees with the drilled interface between calcareous and volcaniclastic members of the Alisitos Formation. A sensitivity analysis strongly suggests that the assumed density function leads to a nearly unique solution of the inverse problem.     

Caledonian metamorphism in part of northwest County Mayo,Ireland

Lewisian gneisses, Moinian and Dalradian sediments, and dolerites have been deformed and metamorphosed under Amphibolite Fades conditions. The metamorphic climax, with the growth of kyanite and staurolite, occurred after the cessation of the second deformational episode and before the onset of the third. Plagioclase growth ceased at or about the time of kyanite and staurolite nucleation. Metamorphic effects become less to the south and southeast while the most advanced stages occur around Inver. A single heat pulse appears to be not directly related to any structure.     

Zur Dynamotheorie stellarer und planetarer Magnetfelder I. Berechnung sonnenähnlicher Wechselfeldgeneratoren

Non-reflectionsymmetric turbulent motions in an electrically conducting fluid provide for an average electromotoric force α parallel to the average magnetic field . This effect – furthermore called α-effect – can lead to a self-excited built-up of magnetic fields by dynamo action. Since by actions of Coriolis forces turbulent motions in rotating systems generally are non-reflectionsymmetric, the explanation of stellar and planetary magnetic fields becomes possible. – In this first part spherical alternating field dynamos are calculated on conditions similar to those at the sun; α-effect and differential rotation provide for dynamo action. – The basic equations, which form a system of partial differential equations, are treated by a separation method; in this way our problem is transformed into a two-parametric eigenvalue problem for an infinite system of ordinary differential equations. The two eigenvalues determine the frequency and the amount of the induction actions necessary for the field maintenance. The solution of this problem was made by an electronic computer. – The results give evidence for the possibility of magnetohydrodynamic alternating field dynamos. Furthermore the magnitude of the calculated eigenvalues and the similarities between the calculated field and the observed solar magnetic field are showing that the sun realizes a dynamo of this kind.