The formation has only been bored through to a depth of 525 ft., where we find an unpierced stratum, 18 ft. thick, of hard marl. Above it are 6 ft. of pure rock-salt, then 81 ft., of marl with thick veins of rock-salt, then 3 ft. of nearly pure salt, then 83 ft. of marl with thin veins of salt, and above it 4 ft. of marl and salt. So far it is evident that the wet seasons predominated, and that marl was deposited far more extensively than salt. For a time, a cycle of dry seasons prevailed; a great change occurred, and a bed of rock-salt, 84 ft. in thickness, was deposited. In other parts, the bed of rock-salt varies from 80 ft. to over 100 ft. in thickness, none of which is perfectly pure, and not more than 20 ft. of it is sufficiently pure to be of commercial use. The greatly changed seasons are indicated by these formations. A portion near the bottom, containing less clay, shows a less copious or less protracted rainfall, and these periods were followed by wet seasons and the presence of much clay. After a time, so much rain fell that for a period sufficiently long for about 30 ft. of marl to deposit, practically no salt formed. Here and there in this deposit are veins of salt, and as these are perpendicular and run as if deposited in rifts or cracks of the marl, the salt doubtless belongs to the next period, when another change occurred and another bed of salt, varying from 50 to 80 ft. in thickness, was deposited. The whole of this bed is fairly full of marl, and, for an untold period, marls were deposited, covering up the rock-salt. The cycles of greater or less rainfalls are traceable in the varying preponderance of marls, in the crystallization of salt, and in the form in which the rock-salt is found. Each minute cube starts as a crystal from some independent point of rock salt, and these increase in numbers until they form a mass of crystallization possessing no distinct lines or features. Had the dry season continued for a long period a thick mass of rock-salt would have been formed. The floor of the lake would have been covered with salt crystals, like the crystal floor of a mine, and the moment the rainy season commenced, and the brooks began to bring in fresh water and mud, these crystals, being attacked by non-saturated water, immediately lost their sharp angles and became covered with a fine layer of mud. As soon as the crystals became completely covered they ceased to dissolve, but the angles and cubes disappeared, and a shapeless mass of mixed salt and mud was formed. With the next dry season, crystallization again set in and another crystal floor was produced, to be again destroyed by the succeeding wet season. This constant growth and destruction of crystals went on for ages, until the salt beds were formed and the water ceased to become super-saturated.