1-20 OF 77 RESULTS FOR

Postmasburg Group

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Journal Article
Published: 01 June 2006
South African Journal of Geology (2006) 109 (1-2): 123–138.
...Kosei E. Yamaguchi; Hiroshi Ohmoto Abstract The occurrence of red shales in Precambrian sedimentary rocks has been used to infer the presence of free O 2 in the atmosphere. Red shale samples from the ~2.2 Ga Gamagara/Mapedi Formation of the Postmasburg Group, South Africa were analyzed...
FIGURES | View All (15)
Journal Article
Published: 01 March 2019
South African Journal of Geology (2019) 122 (1): 39–56.
... assigned to the Paleoproterozoic Transvaal Supergroup. The area intruded by the complex is characterized by abutting and contrasting successions of the upper Transvaal Supergroup (i.e., the Pretoria and Postmasburg groups), the correlation of which is critical to understanding the first significant build...
FIGURES | View All (11)
Image
Modified pre-Kalahari <span class="search-highlight">Group</span> geological map showing discrepancies between cu...
Published: 01 March 2019
as known borehole intersections of the Postmasburg Group on the Circle T and Frylinck farms.
Image
Geographical and structural interpretation of the Kalahari Manganese Field ...
Published: 01 June 2018
the Kalahari deposit, effectively bisecting the study area ( Vafeas et al., 2018 ). The general unthrusted stratigraphic succession of the Voëlwater Subgroup of the Postmasburg Group of the Transvaal Supergroup (After Cairncross and Beukes, 2013 ; (B).
Image
( A ) A total magnetic intensity anomaly map of the Molopo Farms Complex in...
Published: 01 March 2019
, with the recognition of Pretoria Group strata in the area, and an implied unconformable relationship with the Postmasburg Group southeast of Bray.
Image
Plot of δ 13 C vs. δ 18 O for the carbonate unit in the MOM4 drill core (al...
Published: 01 March 2019
). Samples from the MOM4 drill core have high δ 13 C values similar to that seen in the Duitschland and Silverton formations of the Pretoria Group, as well as the Lucknow Formation of the Olifantshoek Supergroup. High δ 13 C values have not been identified in the Postmasburg Group. Note
Image
(A) Summary of U-Pb zircon and baddeleyite age determinations of felsic and...
Published: 02 January 2020
less than 20 Ma are plotted. Probability density distribution diagrams are shown for detrital zircon ages from the Postmasburg Group, the Pretoria Group, and Ventersdorp Supergroup. Data sources are given in Table DR10 (see footnote 1 ). Only results with discordance less than 5% are plotted
Journal Article
Published: 01 December 2006
South African Journal of Geology (2006) 109 (4): 637.
..., Hiroshi (2006). Geochemical and isotopic constraints on the origin of Paleoproterozoic red shales of the Gamagara/Mapedi Formation, Postmasburg Group, South Africa. South African Journal of Geology , 109 , 123–138. © 2006 December Geological Society of South Africa 1. Page 126, Table 2...
Journal Article
Journal: Economic Geology
Published: 01 December 1996
Economic Geology (1996) 91 (8): 1435–1454.
... Formation of the Late Paleoproterozoic Olifantshoek Group. Textural and geochemical similarities with unmetamorphosed karst-hosted manganese deposits suggest that the manganese ores in the Postmasburg manganese field were deposited as residual manganese wad. The ores underwent diagenetic compaction...
Series: Reviews in Economic Geology
Published: 01 January 2008
DOI: 10.5382/Rev.15.12
EISBN: 9781629490229
... of the conglomerates, comprised almost entirely of hematite, constitute lower grade iron ore. The Gamagara Formation, interpreted as the base of the Paleoproterozoic (∼2.1–1.83 Ga) Olifantshoek Supergroup (Fig. 2 ) is overlain by the Paleoproterozoic (∼2.35–2.1 Ga) Postmasburg Group along an interpreted thrust...
FIGURES | View All (13)
Journal Article
Published: 01 November 2015
The Canadian Mineralogist (2015) 53 (6): 981–990.
... to those of the Eastern Belt ( Plehwe-Leisen & Klemm 1995 ). Samples with As-rich tokyoite were retrieved from a drill core provided by Kumba Iron Ore (a member of the Anglo American Group) and obtained from the broader Kolomela area near the town of Postmasburg in the Northern Cape Province...
FIGURES | View All (7)
Journal Article
Published: 01 December 1967
American Mineralogist (1967) 52 (11-12): 1689–1696.
...Waldemar T. Schaller; Maxwell K. Carron; Michael Fleischer Abstract A new analysis of ephesite from the Postmasburg district, South Africa, shows that the lithium content is much higher than previously determined. Ephesite is a trioctahedral member of the margarite group with formula Na(LiAl 2 )(Al...
Journal Article
Published: 01 August 1984
American Mineralogist (1984) 69 (7-8): 803–806.
...George E. Harlow; Pete J. Dunn; George R. Rossman Abstract Gamagarite from Postmasburg district, Cape Province, Republic of South Africa, is reexamined using analytical chemical, infrared spectra, and X-ray diffraction techniques. The data indicate that gamagarite is isostructural...
Journal Article
Published: 01 March 2020
South African Journal of Geology (2020) 123 (1): 1–18.
... is developed on a so-called “bostonite” sill that intruded the Hotazel Formation (Postmasburg Group) in the Avontuur deposit. It represents a saprolitized diabase that can be correlated to the Wolhaarkop ( Holland and Beukes, 1990 ) and Drakenstein ( Wiggering and Beukes, 1990 ) paleoweathering profiles, where...
FIGURES | View All (12)
Journal Article
Published: 30 January 2018
The Canadian Mineralogist (2018) 56 (1): 65–76.
... of cryptomelane from the Postmasburg Manganese Field (Crp1) and the Langdon-annex mine (Crp2). Based on the ideal endmember formula of A + 1–1.5 [M 4+ 7 M 3+ ]O 16 (Biagioni et al . 2012), Mg and Ca were grouped with the A + tunnel cations, i.e ., K and Na. Similarly, Mn 3+ and Mn 4+ occupy the M 4...
FIGURES | View All (8)
Journal Article
Published: 01 June 2006
South African Journal of Geology (2006) 109 (1-2): 81–86.
... as proxies for REY in ambient seawater, but highlight the need for further study. Here, we compare the REY distribution in marine limestone and in silicified dolomite from the Paleo-proterozoic Mooidraai Formation in the Postmasburg Group of the Transvaal Supergroup, South Africa. We show...
FIGURES | View All (4)
Journal Article
Published: 01 June 2002
South African Journal of Geology (2002) 105 (2): 107–134.
... to the east. The volcano-sedimentary sequence of the Postmasburg Group is stratigraphically divided into the Makganyene Formation (diamictite) and Ongeluk Formation (basalt) and Voëlwater Subgroup. The Makganyene, below the Ongeluk Formation, is not identifiable on the seismic section. This may be partly...
FIGURES | View All (16)
Journal Article
Published: 01 June 2018
South African Journal of Geology (2018) 121 (2): 157–170.
... the Kalahari deposit, effectively bisecting the study area ( Vafeas et al., 2018 ). The general unthrusted stratigraphic succession of the Voëlwater Subgroup of the Postmasburg Group of the Transvaal Supergroup (After Cairncross and Beukes, 2013 ; (B). ...
FIGURES | View All (9)
Journal Article
Journal: Geology
Published: 28 October 2019
Geology (2020) 48 (1): 44–48.
... of Paleoproterozoic red shales of the Gamagara/Mapedi Formation, Postmasburg Group, South Africa : South African Journal of Geology , v. 109 , p. 123 – 138 , https://doi.org/10.2113/gssajg.109.1-2.123 . Detrital zircon grains were drilled from thin sections of sandstone from five stratigraphic intervals...
FIGURES | View All (4)
Journal Article
Journal: Economic Geology
Published: 01 November 2002
Economic Geology (2002) 97 (7): 1623–1624.
... of manganese ores in the Kalahari manganese field on both a local and a regional scale. It also provided a fundamental contribution towards our understanding of Paleoproterozoic karst-hosted manganese deposits and associated high-grade iron ores on the Maremane dome between Sishen and Postmasburg. The results...
FIGURES