- Cape Fold Belt
The Cape Fold Belt is the folded sedimentary sequence of rocks in the southwestern corner of
South Africa . It is related to theVentana Mountains nearBahia Blanca inArgentina . The rocks are generally sandstones and shales, with shales forming the valleys and the erosion resistant sandstones forming the parallel mountain ranges, reaching a maximum height atSeweweekspoortpiek (Afrikaans: Seven Weeks Defile Peak) at 2325m.The rocks were laid down as sediments in a coastal delta environment upon the Malmesbury
unconformity in theOrdovician (450ma) period, with the folding subsequently occurring in theCarboniferous andPermian periods during the merging of the supercontinentPangaea . Even though the mountains are very old by Andean and Alpine standards, they remain steep and rugged, owing to the resistant nature of the quartzitic sandstones of the Table Mountain Group. The famousTable Mountain is comprised of hard rocks of the Peninsula Formation of the Table Mountain Group. The geographic range of the Cape Fold Belt is fromCape Town in the west and theCederberg Mountains in the northwest toPort Elizabeth in the east.The mountains, although mediocre in height by world standards, remain extremely majestic and dramatic to the eye. This is due in part to numerous geological factors; The ranges usually have few to no foothills and rise directly from the valley floor. The mountain's base is usually at or near sea level. The ranges are generally steep and rugged, due to their quarzitic
sandstone geology making them very resistant toweathering .Oregeny
The mountains are not particularly ancient, despite their old-looking appearance. They are considered middle-aged in Geologic terms. They were created during continental collision when
Pangaea , the supercontinent formed from the lateCarboniferous toPermian periods. Their stature is mostly due to their weather-resistant rocks of quartziticsandstone , with the shale formations generally forming the valleys, capped by alluvial deposits, which are generallyQuaternary in age.The mountains were folded during this period and were still buried beneath the earth's surface. Due to the extreme temperatures and
lithic pressure at these depths, folding was not a brittle process, as the rocks retained a "plastic" constituency, making the Cape Fold Mountains spectacular in their exposed folded, faulted and twisted sedimentary strata. A number of parallel faults still runs roughly parallel with the coast, having formed during theGondwanaland rifting whenSouth America separated fromAfrica .Patagonia was to the west ofCape Town and theFalkland Islands were to the south during theJurassic period prior to separation. This faulting has caused theTable Mountain Sandstone to be exposed closer to and above sea level close to the coast, but gradually becoming deeper embedded in the overlying strata further inland, excluding areas where folding has causedanticline s to expose the rocks higher up (eg.Swartberg Mountains north of theOudtshoorn Fault.The opening of
Pangaea and subsequentlyGondwanaland also aided in their "conservation" as a range, as theCape Supergroup of rocks were capped by the deposition of theKaroo Sequence ofsedimentary deposits, including theDwyka Formation , which is compacted glacialtill deposited during the latePermian southernice age .The Ranges
The largest individual ranges within the Cape Fold Belt include (translations in brackets) from west to east:
*Cederberg Mountains (Cedar)
*Olifants River Mountains (Elephant's)
*Piketberg (Picket)
*Winterhoek Mountains (Winter corner)
*Skurweberge (Rough or scaly)
*Hex Rivier Mountains (Witch river)
*Du Toitskloof Mountains (a French surname: Du Toits canyon )
*Drakenstein Mountains (Dragon stone)
*Simonsberg (Simon's)
*Hottentots-Holland Mountains (Hottentot: old name for Khoi aboriginal inhabitants)
*Kogelberg (Bullet, or cone-shaped)
*Stettynsberge (probably a surname)
*Langeberg (Long)
*Riviersonderend Mountains (River without end)
*Kleinrivier Mountains (Small river)
*Witteberge (White)
*Swartberg e (Black)
*Outeniqua Mountains (aboriginal: place of honey)
*Langkloof Mountains (Long valley)
*Kouga Mountains (aboriginal)
*Tsitsikamma Mountains (aboriginal: place of much water)
*Baviaanskloof Mountains
*Zuurberge (Sour, acid or acidic)(berg isAfrikaans for mountain. Plural is 'berge')
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