0 a type of soft, grey rock, usually formed from clay that has become hard, that breaks easily into thin layers --
1 a type of rock consisting of solid material that has been pressed into thin layers --
The abundance of shales in the central lake deposits shows a low-energy depositional setting.
The latter was described as "massive sandstones and conglomerates with interbedded sandy shales which are of continental origin".
Many of the black shales exhibit few features optically due to their fine grain size.
The lower member (max. c. 600 m) is composed mainly of thick clay shales interbedded with thin sandy limestone beds (packstones and wackestones).
The necromass concentrations of all nutrients on sandstone were lower than on shale.
Thus, during preparation the shale projectiles used were worked into near spherical shape.
Most likely the organic matter is derived from the carbon- and uranium-rich bituminous shale of the target.
The stippled bands represent the lower and upper black shales.
