Journal of Asiatic Society of Bengal . h differ totally in appearance from those of the carboniferousrocks. Some of them bear a close resemblance to the limestones ofthe lias formation. They are hard and splintery and present a conchoidal fracture,When bruised, the darker varieties emit the odour of sulphurettedhydrogen. They dissolve rapidly in muriatic acid, leaving a considerablesediment of silica in flakes mixed with a little organic matter. Theycontain a little carbonate of iron with a trace of alumina, but nomagnesia when undisturbed. At Kalibagh, however, where large massesof the limest
Journal of Asiatic Society of Bengal . h differ totally in appearance from those of the carboniferousrocks. Some of them bear a close resemblance to the limestones ofthe lias formation. They are hard and splintery and present a conchoidal fracture,When bruised, the darker varieties emit the odour of sulphurettedhydrogen. They dissolve rapidly in muriatic acid, leaving a considerablesediment of silica in flakes mixed with a little organic matter. Theycontain a little carbonate of iron with a trace of alumina, but nomagnesia when undisturbed. At Kalibagh, however, where large massesof the limestone repose on salt marl, they have a remarkably shivered 1853.] Report on the Geological Structure of the Salt Range. 271 appearance, and magnesia may be detected in them in small specimen of the limestone of a dark grey colour from Umlakhail inthe Chichalee Range yielded on analysis the following results:— Silica with a little organic matter, Carbonate of iron with a trace of Alumina, Carbonate of Lime, At Umlakhail a bed of argillaceous limestone occurs presenting onits upper surface a series of waves passing across the bed at rightangles to its strike. These are about \\ feet apart, and their crestabout two inches above the general level of the bed. It presentsthe appearance represented in the annexed figure. A bed of shale, which occurs beneath it, is, fora short distance, affected in argfJaT|^|gg|^i^=j similar way; but the surfaceof a limestone bed on whichthe shale rests, is perfectlyhorizontal, and does not seem to have suffered in the least from thelateral compression to which the upper bed has been subjected. Theforce exerted seems to have been nearly sufficient to have fracturedthe bed, as, along the crests of some of the waves and parallel to these,cracks may be observed extending some depth into the bed, which isnot more than two feet thick. It is difficult to imagine how anylateral force could have been applied, so as only to
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