"Q" 

Quaternary (undivided) 

"Qe" 

Holocene 

"Qp" 

Pleistocene 

"QT" 

Cenozoic 

"T" 

Tertiary 

"Mz" 

Mesozoic 

"TK" 

Tertiary-Cretaceous

"K" 

Cretaceous 

"Kl" 

Lower Creteceous" 

"KJ" 

Cretaceou-Jurassic 

"J" 

Jurassic 

"Jl" 

Lower Jurassic 

"JTr" 

Jurassic-Triassic

"Tr" 

Triassic 

"Trl" 

Lower Triassic 

"MzPz" 

Mesozoic-Paleozoic 

"KC" 

Cretaceous-Carboniferous 

"JC" 

Jurassic-Carboniferous

"Pz" 

Paleozoic 

"P" 

Permian 

"TrP" 

Triassic-Permian 

"PC" 

Permian-Carboniferous

"C" 

Carboniferous 

"CD" 

Carboniferos-Devonian 

"D" 

Devonian 

"Du" 

Upper/Middle Devonian 

"DS" 

Devonian-Silurian

"S" 

Silurian 

"SO" 

Silurian-Ordovician 

"OCm" 

Ordovician-Camrian

"pCm" 

Precambrian 

"PzpC" 

Paleozoic-Precambrian 

"Qv" 

Quaternary Igneous

"Ti" 

Tertiary Igneous 

"Mi" 

Mesozoic Igneous

"MiPi" 

Mz-Pz Igneous

"Pi" 

Paleozoic Igneous

"Kimb" 

Kimberlites 

"S-d" 

Salt Domes 

"H2O" 

Water (River 0r Lake) 

"Sea" 

Sea 

"oth"S_d" 

Areas outside of African Continent