structures are typically found in sandstones of the Kernave Fm, also in some levels of the Arukula and Leivu Fms, but not in southern sections (Figs 1, 3; Kleesment 2008).
Logan's "Recapitulation" of Division 5 reads as follows: "dominated by red shale, reddish grey sandstone with occasional "drift plants" and "concretionary
limestone", and minor greenish grey sandstone, totally 2082 ft 0 in".
It is speculated that the fossil was encased in a concretionary
mass of sand in the Citronelle Formation cemented by carbonate, which assured its durability despite reworking.
The Fe and Al composition of the oxalate extract from concretionary
material at 10-30 cm under oak is consistent with a process similar to podzolisation.
It is found in numerous habits: massive, earthy, compact, nodular, botryoidal, stratified and concretionary
. (All of these varieties, along with a lesser or greater proportion of hydrozincite and hemimorphite, are given the name "calamine" by the miners.) Smithsonite occurs here in a large number of colors, caused by the inclusion of small particles of copper carbonates, cinnabar, greenockite, iron oxides, etc.
Hematite is sparsely present as black, oolitic concretionary
coatings throughout the oxidized zones of the Brick 2 and Lead-Silver 7.
At level 170, a tunnel crossed a pocket of concretionary
smithsonite containing arborescent copper on a chalcocite matrix.