STRATIGRAPHY |
LITHOLOGY |
CHARACTERISTIC |
INTRUSIVE
AND METAMORPHIC ROCKS |
| Dolerite and syenite
intrusions |
Dolerite/Syenite |
Active/compressible,
excavatibility problems (rock) |
| Basement Complex:
Halfway House Granite |
Granite/ granodiorite |
Collapsible/ excavatibility
problems |
| Basement Complex:
Mafic and related rocks |
Amphibolite, ultramafic schist |
Active/compressible |
SEDIMENTARY
AND VOLCANIC ROCKS |
| Tertiary
and Quaternary Deposits |
Eolian/Colluvial material |
Collapsible/ compressible/
active/erodible |
| Alluvium |
Drainage problems/shallow water
table, active/ compressible/ collapsible |
| SUPER GROUP |
GROUP |
SUBGROUP |
FORMATION |
|
|
| Karoo |
Ecca |
|
Vryheid |
Sandstone, shale, coal,
conglomerate |
Active/compressible/collapsible,
drainage problems |
| Dwyka |
|
|
Tillite |
| Transvaal |
Pretoria |
|
Hekpoort |
Andesite, agglomerate |
Active |
| Timeball Hill |
Shale, quartsite |
Shallow
excavatibility, collapsible, drainage problems |
| Rooihoogte |
Chert breccia, conglomerate,
shale, quartsite |
| Chuniespoort |
Malmani |
|
Dolomite, chert |
Sinkhole/doline formation |
| |
|
Black Reef |
Quartsite, shale, conglomerate |
Shallow excavatibility |
| Ventersdorp |
Platberg |
|
Kameeldoorns |
Breccia, conglomerate, sandstone,
shale, lava, quartz porphyry |
Active/compressible |
| Klipriviersberg |
|
Alberton |
Andesitic lava |
| Westonarea |
Tuff, basaltic lava |
| Witwatersrand |
Central Rand |
Turffontein |
|
Quartsite, conglomerate, shale |
Shallow
excavatibility, instability (shallow undermining) |
| |
Booysens |
Shale, quartsite |
| Johannesburg |
|
Quartsite, conglomerate |
| West Rand |
Jeppestown |
|
Shale, quartsite, conglomerate,
lava |
Compressible |
| Government |
|
Quartsite, conglomerate, shale |
| Hospital Hill |
|
Quartsite, shale |
Shallow excavatibility |
| |
Dominion Reef |
|
|
Quartsite porphyry |
Collapsible/ excavatibility
problems |
