Professor Birbal Sahni

Some years later, B. Sahni, then a paleobotanist at the University of Lucknow, reported the existence of numerous plant microfossils in samples taken from the Salt Range Formation at the Khewra and Warcha salt mines. Previously, doubt had been cast on plant fossils from the Salt Range Formation. Critics, said Sahni, had pointed out that “in such a highly soluble and plastic substance as the Salt Marl, extraneous material might have penetrated through solution holes or have been enveloped during relatively modern earth movements.”

But deep within the mines, Sahni found deposits where such objections could not apply. The salt in these places ran in layers separated by thin layers of saline earth, locally called “kallar.” Sahni noted that “the kallar lies closely interlaminated with the salt, in beds which run continuously for long distances and which, although visibly tilted, show no other visible signs of disturbance.”

According to Sahni, the salt layers accumulated from evaporation of sea water in coastal lagoons, whereas the kallar represented dust and dirt blown on to the drying salt by the wind. Sahni guessed that the kallar might contain pollen and other plant microfossils. When he examined specimens, he found this to be so: “Every single piece has yielded microfossils…The great majority are indeterminable as to genus and species, being mainly shreds of angiosperm wood, but there are also gymnosperm tracheids with large round bordered pits, and at least one good, winged six-legged insect with compound eyes.” To Sahni this meant that the Salt Range Formation must be Eocene rather than Cambrian. Sahni later found plant fragments not only in the kallar, but in associated solid rock layers composed of dolomite and shale.                                                                 BACK TO DOORS              BACK TO HOME