Thesis (DSc.)--Stellenbosch University, 1952. / ENGLISH ABSTRACT: The ideal geological column of the Kimberley-Elsburg Series
in the East Rand Basin is described, with particular reference to
the IQrnberley group of sediments.
A system of nomenclature has been devised, and it is suggested
that it could'also be used in other parts of the large structural
basin, stretching from Johannesburg'in the north to near Theunissen
in the south,. and from .Klerksdorp in the west to Greylingstad in the
east.
The stratigraphy of individual areas in the East Rand Basin is
described in detail, and it is shown that certain stratigraphic.units
display a remarkable regularity, maintaining their lithologica~
characteristics bver large areas, persisting also into the Greylingstad-
Balfour district, the Central Rand, the West and Far West Rand, the
Klerksdorp area, and into the Orange Free State goid field.
In the East Rand Basin the May Reef is the principal gold
carrier, and is of economic importance in certain mines. In the
Orange Free State gold field the lowermost Kimberley reef is also of
economic importance.
Three regional unconformities have been recognised in the part
of the column extending from below the Kimberley Shales to above the
May Reef. The May Reef covers the upper one', and owes its existence
to this period of erosion. The history of this reef could be traced
back to its parent rock~ in this case, stratigraphically older
auriferous gravels. The author believes that the unconformity below
the May Reef developed as a result of sub-aqueous erosion. The. oldest
erosion surface probably developed in the same way. The middle one
developed largely on the land, but was subsequently submerged.
It is concluded that the sediments of the Kimberley-Elsburg
Series were deposited in the marine neritic environment, i.e. in
a sea of substantial but not excessive depth.
A few remarks have been added on the metamorphism of the
System. An interesting feature in this connection is the occurrence
of ubiquitous authigenic rutile in the form of minute needles and
knee-shaped twins. It appears that the rutile developed as a stress
mineral, ilmenite having been the original detrital constituent. / AFRIKAANSE OPSOMMING: geen opsomming
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/54003 |
| Date | January 1952 |
| Creators | De Jager, F. S. J |
| Contributors | Stellenbosch University. Faculty of Science. Dept. of Earth Sciences. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 89 p. : ill. |
| Rights | Stellenbosch University |
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