Natural heritage.
 Geology.
The geology of the Melville Koppies Nature reserve.
By Prof.W.J. van Biljon M,Sc., Ph.D
The University of Johannesburg formerly Randse Afrikaanse Universiteit.
A long time ago, probably 2 500 million years ago, a large inland lake existed in the
southern Transvaal (the area between the Vaal River and Limpopo River) and
northern Free Sate. From high mountains on the fringe of this lake pebbles, sand and
mud, together with small amounts of minerals such as gold and uraninite, were
washed into the lake until a vast thickness of nearly 7 500 metres of material has
accumulated on a floor of ‘archean’ granite. The centre of the lake gradually subsided
so that the edges were upturned (like a saucer). As a result of the great weight of the
overlying material, the original mud, sand and pebbles were compacted into hard
rocks known as shale, quartzite and conglomerate respectively. The rocks forming the
northern rim of this basin are today exposed at the surface from Springs to
Randfontein and are known to continue under younger formations, as far as
Klerksdorp, from where the ridge swings to the south into the Free State. The group
of rocks are collectively known as the Witwatersrand Supergroup.
The quartzites, being composed mainly of the mineral quartz, are the most resistant to
weathering and therefore usually form ridges. The shales, on the other hand, are soft
and tend to occupy the valleys. The conglomerates, in which most of the gold and
uraninites occur, form only thin bands known as ‘reefs’ fairly high up in the
succession where they are being mined for their economic mineral content.
In the Melville Koppies nature reserve, the ‘floor’ and the lowermost rocks of the
Witwatersrand Supergroup can be seen. The rock onto which this supergroup was
deposited is normally granite, but in this particular area the floor is formed by
‘diorite’, a rock composed essentially of feldspar and amphibole with no quartz. This
rock weathers very readily to a deep red soil, with the result that the actual rock-type
cannot be seen in the Reserve. Examples are abundant, however, at many places in
Emmarentia, Roosevelt Park and Linden. In the Reserve, the slope which leads from
Judith Road to the foot of the ridge, is underlaid by this diorite. Near the bottom of the
slope, the colour of the soil is distinctly red and clayey, but as one approaches the
ridge it becomes sandier as a result of contamination with sand derived from the
quartzite. Many pebbles of white vein quartz, as well as boulders of quartzite with a
sugary texture, have also rolled down the slop. The colour of these rocks is often
brown as a result of coating of iron oxide.
The higher portion of the Reserve is formed by alternating layers of quartzite and
shale, which dip at angles ranging from 25* to 42* to the south. These rocks, as a
result of later Earth movements, have been extensively faulted and disturbed, so that
in places only isolated remnants of original quartzite bands remain. Vein quartz and
sometimes dense red mylonite (crushed rock) is usually well developed in the vicinity
of these faults.
The quartzite is normally white to pinkish in colour, but may be brown on the surface
as a result of iron staining. Original sedimentary structures like ripple marks and cross
bedding are not well developed, but may be observed in a few places.
The shale, being soft, does not outcrop well, but small chips can usually be seen in the
soil, especially where moles have been at work. The shale varies in colour from light
grey, blue grey, green to pink, pinkish brown and deep brown, while, where the nature
trail crosses the lowermost quartzite, an unusual khaki-coloured variety can be seen.
Although some of the shales contain a fair amount of iron minerals (Hematite and
magnetite) the source of the iron ore, which was used in the smelter at Melville
Koppies, was more likely the banded iron formation known as the Contorted Bed...
This iron formation occurs somewhat higher up in the succession.
During the period of faulting a certain amount of diabase intrusion also took place. In
the extreme south of the Reserve, some boulders of diabase are found near the road,
but it is not certain whether these are in place or have been dumped there.
Just above the second main quartzite ridge from the bottom, and near the centre of the
area, some boulders of diorite can be seen in the soil. Unfortunately, this rock also
weathers readily and the extent of the diabase cannot be determined. From the nature
of the soil, however, it is quite likely that several dykes of diabase cut through the
main quartzite in the south western portion of the area.
 Trees
Trees of Melville Koppies Nature Reserve.
Common name
Scientific name
Acacia caffra
Acacia karoo
Acacia robusta
Acacia tortillas
Acokanthera oppositiifolia
Brachylaena rotunda
Buddleja saligna
Buddleja salviifolia
Canthium gilfillanii
Canthium mundianum
Celtis africana
Combretum erythrophylum
Combretum molle
Cussonia paniculata
Diospyros lycioides
Dombeya rotundifolia
Common Hookthorn
Sweet thorn
Enkeldoring
Umbrella thorn
Common thorn bush
Mountain silver oak
False olive
Sagewood
Velvet rock alder
Rock alder
White stinkwood
River bushwillow
Velvet bushwillow
Cabbage tree
Blue bush
Common wild pear
Ehretia rigida
Ficus ingens
Grewia occidentalis
Gymnosporia buxifolia
Halleria lucida
Kiggelaria africana
Leucosidea sericea
Maerua caffra
Mudulea sericea
Nuxia congesta
Olea europea subs. africana
Olinia emarginata
Osyris lanceolata
pavetta gardeniifolia
Pittosporum viridiflorum
Protea caffra
Rhamnus pyroides
Rhus lancea
Rhus leptodictya
Rhus pyroides
Rothmania capensis
Scolopia zeyheri
Strychnos pungens
Tapiphyllum parvifolium
Vangueria infausta
Zanthoxylum capense
Ziziphus mucronata
Puzzle bush
Red-leaved fig
Cross-berry
Common spike-thorn
Tree fuschia
Wild peach
Ouhout
Bush-cherry
Cork bush
Wild elder
Wild olive
Hard pear
Transvaal sumach
Common bride’s bush
Cheesewood
Common sugar bush
Dogwood
Karree
Mountain karee
Common wild currant
Cape gardenia
Thorn pear
Spine-leaved monkey orange
Mountain medlar
Wild medlar
Small knobwood
Buffalo thorn
 Grasses
Grasses of Melville Koppies
Botanical name
Common name
Alloteropsis semialata
Andropogon schirensis
Aristida congesta
Aristida junciformis
Bewsia biflora
Brachiaria nigropedata
Brachiara serrata
Cymbopogon excavatus
Cymbopogon plurinodisnarrow0leaved
turpentine grass
Black-seed grass
Stab grass
Spreading three-awn
Ngongoni three-awn
False love grass
Black-footed signal grass
Velvet signal grass
Broad-leaved turpentine grass
Cymbopogon validus
Cynodon dactylon
Digitaria eriantha
Digitaria mondactyla
Digitaria tricholaenoides
Diheteropogon amplectens
Diheteropogon filifolius
Elionurus muticus
Eragrostis capensis
Eragrostis curvula
Eragrostis gummiflua
Eragrostis racemosa
Eastachys paspaloides
Harpochloa falx
Heteropogon contortus
Hyparrhenia tamba
Hyparrhenia hirta
Loudetia simplex
Melinis nerviglumis
Melinis repens
Monocymbium cerisiiforme
Panicum maximum
Panicum natalense
Pogonarthria squarrosa
Schizachryium sanguineum
Setaria lindenbergiana
Setaria megaphylla
Setaria nigrirostris
Setaria sphacelata
Sporobolus pectinatus
Sporobolus pyramidalis
Themeda triandra
Trachypogon spicatus
Tristachya leucothrix
Tristachya rehmanii
Urelytrum agropyroides
Giant turpentine grass
Couch grass
Finger grass
One-finger grass
Purple finger grass
Broad-leaved bluestem
Thread-leaved blue stem
Wire grass
Heart-seed love grass
Weeping love grass
Gum grass
Narrow heart love grass
Fan grass
Caterpillar grass
Spear grass
Common thatching grass
Blue thatching grass
Common russet grass
Bristle-top red top
Natal red top
Boat grass
Guinea grass
Natal Panicum
Pagoda grass
Red autumn grass
Mountain bristle grass
Broad-leaved bristle grass
Black seed bristle grass
Common bristle grass
Fringed drop seed
Catstail dropseed
Red grass
Giant spear grass
Hairy trident grass
Broom trident grass
Quinine grass
For further information, consult ‘Guide to grasses of Southern Africa’, by F. van
Oudtshoorn, published by Briza
 Flowers of Melville Koppies.
Melville Koppies has a wealth of indigenous flora. Over 500 species have been
collected and preserved at the Moss herbarium at the University of the Witwatersrand.
In early spring, the veld is dotted with exquisite, brightly coloured little ‘pre rain
flora’, so named because the flowers appear before the rains. Some are shy and only
flower in the afternoons. If the veld has been burnt, they are very visible. As the year
progresses, a rich variety of flowers make their seasonal appearance. Some of the
more flamboyant of these are the Pineapple flower, Bobbejaanstert, summer Aloe, the
Red paint brush, Clematopsis and a great variety of daisies. Others have a more
ethereal quality like the lilies, ground orchids and wild apricots. Aloes and August
gold brighten the veld during the winter months.
Explore the veld and enjoy our floral Heritage. If you wish to know more about them,
join a guided tour or/and bring your reference books with you.
Peter Johnson, a MK committee member, has produced a booklet of ‘Flowering
times on the Melville Koppies’ (do link here). Every month has a list of flowers
which should be in bloom that month. The list is colour coded and has page references
to the ‘Field guide to the flowers of the Highveld’ by Braam van Wyk and Sasa
Malan. This is on sale on open days.
Allan Abel has written a report on the ORCHIDS OF MELVILLE KOPPIES. (do link
here)
 Fungi of Melville Koppies
Fungi are a highly specialised microbiology field. This is because many of the
intricate structures are only visible with a magnifying glass. Some of the fungi are
minute and easily overlooked. Many of the fungi prefer moist conditions and rich
leafy composted areas so the arboretum of Melville Koppies is a good place to
explore in February which is usually one of the wetter months.
Most fungi are short-lived, but there are some, like the big parasitic dinner plate-like
Ganoderma, that live on trees, causing heart rot and ultimately death. A strange
looking fungus is the symbiotic Podaxis pistillaris (Ink Cap), a phallic-looking
mushroom that pops out of termite mounds. It benefits from the moisture and humus
in the mound. It is inedible, unlike the Termitomyces umkowaani (Beefsteak
Mushroom) always associated with termites. These mushrooms are delicious, full of
flavour and can be braaied with butter, garlic and salt.
A word of warning. Only eat mushrooms picked by a fundi. Otherwise you might get
a bit of Amanita phalloides (duiwelsbrood) in your meal and 30g will kill you. It will
be slow poison as symptoms only appear 6-24 hours after eating and by then the
toxins will have caused extensive kidney and liver damage.
Further information about fungi is available in books ranging from first field guides
for beginners to books for specialists.
If you are interested in fungi, contact Marieka Gryzenhout
(marieka.gryzenhout@fabi.up.ac.za). She is a passionate expert and has a mailing
list of fellow fungi fundi fanatics. She will also direct you to further sources of
information.
Insects
This has a cast of millions!
In 2005, Strilli Oppenheimer commissioned a survey of bugs in 24 sites in Gauteng.
She felt that insect numbers have declined considerably, possibly due to light
pollution, insecticides etc. Melville Koppies was one of the sites surveyed. Scientists
Peter Hawkes and Max Clarke did a survey over a few days. They collected flying
insects in a special tent, insects on the grasses with a net and crawling insects in traps
sunk into the ground. Each insect has to be identified, usually under a microscope,
and counted. This is very time consuming so an assistant has been employed to count
the millions of ants collected.
The results are still being collated (2008) but it seems that Melville Koppies’ insects
are doing quite well. Perhaps this is because we use no insecticides, promote
indigenous vegetation and have no electricity to light up the reserve at night.
In 2008, Megan Field, a Wits student, is doing research on termites for an honours
degree. She is monitoring the internal temperatures of the mound over a year.
Research is one way of defending our natural heritage because it reveals the treasures
of Melville Koppies and other reserves.
Reptiles
Recently, a brown house snake decided to drape itself around the gate in Kafue Rd
while it digested a meal of a mouse. This took several days. In the meantime, it was
an excellent security guard for Melville Koppies as few people dared to use the
entrance. It was also a good reason for visitors to stay on the paths as it was living
proof that there are snakes in the grass.
The only dangerous snake that MK has is the Rinkhals, or spitting cobra which is
endemic to the whole of South Africa. The Rinkhals is only dangerous if it feels
threatened and then it blows up its hood to look bigger and more threatening. Stand
still and it will escape quickly from the danger presented by a human.
Other reptiles seen on MK have been lizards, geckoes, agamas, tortoises, and a
variety of harmless snakes
Mammals
Large mammals that once roamed Melville Koppies have long since been hunted to
extinction. Only small, mostly nocturnal mammals remain.
There are plenty of mole rats because their mounds are everywhere except on the
rocky ridges. One was seen during the day bumbling along near the lecture hut.
Hedgehogs are occasionally seen if there has been a lot of rain. Sometimes a slender
mongoose or yellow mongoose races across a path. The African Civet has left
middens and the Lesser Spotted Genet has been spotted near the spruit. It may not be
resident. The University of the Witwatersrand has done some small mammal trapping
and found vlei rats, multimammate mice, striped field mice and Rock Elephant
shrews. Sadly, a survey in 2008 by Wits student, Megan Mackay, only trapped
multimammates and a vlei rat. Because Melville Koppies is an island, if a species
disappears, it cannot be replaced from other nature areas.
 Birds of Melville Koppies.
Some common/typical birds of Melville Koppies.
name
Remarks
Barbet, Crested
Barbet, Black-collared
Barbet, Acacia Pied
Bee-eater, European
Bulbul, Dark-capped
Seedeater, Streaky-headed
Cape White-eye
Cisticola, Rattling
Cisticola, Wailing
Coucal, Burchell’s
Crow, Pied
Cuckoo, Diderick
Cuckoo, Klaas’s
Cuckoo, Red-chested
Dove, Cape-Turtle
Dove, Laughing
Dove, Red-eyed
Flycatcher, Fairy
Flycatcher, Fiscal
Flycatcher, Paradise
Spurfowl, Swainson’s
Go-away-bird, Grey
Goose, Egyptian
Guineafowl, Helmeted
Heron, Black-headed
Honeyguide, Lesser
Hoopoe, African
Wood-Hoopoe, Green
Ibis, Hadeda
Martin, Rock
Mousebird, Red-faced
Mousebird, Speckled
Neddicky
Eagle-Owl, Spotted
Pigeon, Feral
Pigeon, Speckled
Lapwing, Crowned
Prinia, Black-chested
Bishop, Southern Red
Robin-chat, Cape
Bokmakierie
Fiscal, Common
Boubou, Southern
Sparrow, Cape
Starling, Cape Glossy
Mynah, Common
Starling, Pied
Sunbird, Amethyst
Sunbird. White-bellied
Swallow, Barn
Swallow, Greater Striped
Swallow, White-throated
Swift, Little
Palm-Swift, African
Swift, White-rumped
Resident, machine-like call
Resident. Duet call
Resident, nasal tin trumpet call
Summer migrant
Resident
Resident
Resident
Resident, tops of bushes
Resident, rocky outcrops
Resident
Resident
Breeding local migrant
Early spring
Breeding local migrant
Resident
Resident
Resident
Winter, small black & white
Resident, black and white
Breeding local migrant
Terrestrial resident
Recent resident
Calling and flying over
Terrestrial resident
Flying over
Brood parasite of barbets
Resident
Resident, noisy parties
Resident
Breeding local migrant
Resident, small flocks
Resident, small flocks
Resident in bushes
Resident, nocturnal
Naturalised exotic
Flying over, fast
Resident, ground nesting
Resident
Resident
Resident
Resident yellow shrike
Resident, black & white
Resident, black & fawn
Resident
Resident
Naturalised exotic
Resident
Resident
Resident
Migrant
Breeding local migrant
Breeding local migrant
Fast flying local migrant
Fast flying local migrant
Fast flying local migrant
Thick-knee, Spotted
Thrush, Karoo
Warbler, Willow
Masked-Weaver,Southern
Woodpecker, Cardinal
Wryneck, Red-throated
Resident, ground nesting
Resident
Migrant
Resident
Resident
Resident
 The Westdene Spruit.