Publication Volume 3; Geological Series (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 Excerpt: ...general a dull hematite-red, shading to darker about the edges of the meteorite. The smoothness and color give an appearance much as if the surface had been coated with a red varnish. The most remarkable feature of this front surface is a system of cracks or fissures which transverse it. These cracks appear to be quite independent of the contour of the surface. In general they may be said to mark triangular areas, the sides of the triangles being about two inches (5 cm.) in length. In width the fissures varv, but rarely exceed one millimeter. As shown bv sections and by pushing a wire into them they penetrate quite deeply into the mass of the meteorite, some being traceable an inch (2.5 cm.) below the surface. Their extension downward is usually in a slanting direction and not perpendicularly. Sections of the meteorite also show cracks running parallel with the surface at a distance of about one-half inch i1 cm.) below it, and others extend inward from the side and rear of the meteorite. The prominent and visible cracks are, however, all on the front side. That these cracks are due to the necessity of a contracted exterior adapting itself to a larger interior there can be no doubt. Whether, however, their origin is to be ascribed to heating produced by the passage of the meteorite through the atmosphere and consequent contraction upon cooling, or to slower processes of weathering after its fall is not certain. Shrinkage cracks observed upon meteorite crusts at the time of fall are usually of a finer pattern than those here seen and penetrate little below the crust. The rusted character of the interior of this meteorite shows that it has long been exposed to the weather. The Dona Inez meteorite, which was exposed to similar climatic conditions, is described ...