Some account of the general and medical topography of Ajmeer / by Robert Hamilton Irvine.

Date:
1841
Catalogue details

Licence: Public Domain Mark

Credit: Some account of the general and medical topography of Ajmeer / by Robert Hamilton Irvine. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    places where the strata have been ruptured, or cut through, to form valleys, or the courses of rivers : this is the only way in which the term “ trap’^ can be applied to these strata, from the meaning of the word trappa” (in Sweed- ish “ a stair’^). Trap, in the proper geological accepta- tion, being a natural family of rocks, having a tendency to assume a columnar formation, or to divide into steps form- ing natural terraces, abounding in horneblende and angite, and being generally of a greenish or blackish colour, and occurring in the primary, transition and tertiary formations : it is therefore quite evident that the term does not apply to the plateau of central India ; which consists, excepting in the ridges of hills, of horizontal strata of silicious sandstone of the variegated variet}'-, in thick strata split in various directions by deep fissures, generally at right angles and continuous to great depths, as becomes especially evident on inspecting the banks of the rivers. The sandstone is generally massive ; but, is often split into slabs, and in some places becomes sandstone slate : it varies in colour from pure white to pinkish or brown, and is often streaked : and contains nodules and irregular fragments of iron ore, quartz, and jasper, in many places. The third variety of sandstone, or pure free-stone, is not found in the many parts of the Patar that I have examined. It seems there- fore evident that the Patar is of the variegated sandstone (or tertiary) formation. The geological and mineralogical remarks made by Colonel Todd, are often inaccurate. Thus the bed of the Chumbul is described as shewing milk-white trap whereas the substance meant is quartz rock, which occurs abundantly in the bed of the Chumbul, below the sandstone strata, and varies from white to grey, massive and semi- transparent : similar quartzoze sandstone also abounds, one kind of which is very fine-grained, compact, hard, white, and opaque, of which the images at Barolli in Mewar are formed. Todd also describes the Jain temple at Ajmeer as being constructed of limestone whereas, the material is a
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