Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa
Thesis (MSc)--Stellenbosch University, 2015.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | en_ZA |
| Published: |
Stellenbosch : Stellenbosch University
2015
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613962090053632 |
|---|---|
| access_status_str | Open Access |
| author | Grobbelaar, Mareli |
| author2 | Rozendaal, Abraham |
| author_browse | Grobbelaar, Mareli Rozendaal, Abraham |
| author_facet | Rozendaal, Abraham Grobbelaar, Mareli |
| author_sort | Grobbelaar, Mareli |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2015. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/97091 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:44:27.789Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/97091 A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa Grobbelaar, Mareli Rozendaal, Abraham Mikes, Daniel Stellenbosch University. Faculty of Science. Dept. of Earth Sciences. Diamictites -- South Africa UCTD Sedimentary rocks -- South Africa Sedimentary basins -- South Africa Thesis (MSc)--Stellenbosch University, 2015. ENGLISH ABSTRACT: Diamictites are sedimentary deposits that originate from a number of different environments, the most common being associated with a glacial environment. Although this association is not, in all cases correct, it is still being used due to the lack of knowledge to confidently identify, classify and interpret a depositional environment for diamictite deposits. During the late Carboniferous to early Permian, two diamictite deposits formed during the development of the Cape Basin and Main Karoo Basin in the southern margins of South Africa. These deposits are known as the Miller diamictite and Dwyka diamictite. The latter is well known and was deposited during the Karoo-deglaciation. The Dwyka diamictite is often referred to as Dwyka Tillite. This is an inappropriate reference owing to that not all of the Dwyka deposits are directly formed as a result of glacial contact. The origin of the Miller diamictite is uncertain, but there are suggestions that its origin can be traced to either a glacial or debris flow deposit formed in a deltaic environment, thus referred to by some as a tillite and others as a diamictite. To establish the sedimentary environments of the above mentioned diamictite deposits in the study area, two facies models were presented with a notable bias for the second model. The first model represents a continuous sedimentation cycle between the closing of the Cape Basin and opening of the Main Karoo Basin, whereas the second model demonstrates an erosional break (hiatus) between the depositions of the above mentioned basins. Derived from the use of the second model, it can be concluded that the Miller diamictite can indeed be classified as a diamictite from a textural interpretation. Both diamictites (Miller and Dwyka) cannot be referred to as tillite deposits since none show evidence of direct glacial contact. The Miller and the Dwyka are both diamictites, but were formed in different sedimentary environments. The Miller diamictite is a product of debris flow deposits from the slope of a braided delta, whereas the Dwyka diamictite represents distal glacio-marine “rain-out” deposits. AFRIKAANSE OPSOMMING: Diamiktiete is sedimentêre neerslae afkomstig vanaf verskillende omgewings en dit word meestal met n glasiale omgewing geassosieer. Alhoewel hierdie assosiasie nie in alle gevalle korrek is nie, word dit nog steeds gemaak as gevolg van die gebrek aan kennis om diamiktiete met selfvertroue te identifiseer, te klassifiseer en 'n afsettingsomgewing vir die sedimente te interpreteer. Gedurende die laat Karboon tot vroeë Permiese tydperk het twee diamiktiet afsettings gevorm gedurende die vorming van die Kaap Supergroep Kom en Karoo Kom in die suidelike grense van Suid-Afrika. Die afsetting staan bekend as die Miller diamiktiet en Dwyka diamiktiet. Laasgenoemde is redelik bekend en is gedurende die Karoo gletser ontvormings tydperk gesedimenteer. Die Dwyka diamiktiet word dikwels Dwyka Tilliet genoem, wat onvanpas is aangesien nie al die Dwyka neerslae direk gevorm het as gevolg van direkte glasiale kontak nie. Die oorsprong van die Miller diamiktiet is egter onseker. Dit word veronderstel dat die Miller diamiktiet óf deur 'n gletser, of puin vloei neerslag gevorm het in 'n deltaiese omgewing, dus word daarna verwys as 'n tilliet of ʼn diamiktiet. Om die sedimentêre omgewings van die twee bogenoemde diamiktiet afsettings in die studie area te bevestig, is twee fasies modelle aangebied met 'n voorkeur aan die tweede model. Die eerste fasies model verteenwoordig n siklus van ongebroke sedimentasie tydens die sluiting van die Kaapse Kom en die opening van die Karoo Kom. Die tweede fasies model verteenwoordig n hiatus tussen die afsetting van die bogenoemde komme. Gegrond op sy teksturele samestelling kan die Miller diamiktiet inderdaad as 'n diamiktiet geklassifiseer word. Beide diamiktiete (Miller en Dwyka) kan nie as tilliet neerslae beskou word nie, aangesien geen bewyse gelewer kan word van afsetting as gevolg van direkte glasiale kontak nie. Die Miller en Dwyka is n diamiktiet, maar is gevorm in verskillende afsettingsomgewings. Die Miller diamiktiet is 'n produk van die puin vloei neerslag vanaf die helling van ‘n delta, terwyl die Dwyka diamiktiet verteenwoordig ‘n afgeleë glasio-mariene “uit-reen” neerslae. 2015-05-20T09:29:39Z 2015-05-20T09:29:39Z 2015-04 Thesis http://hdl.handle.net/10019.1/97091 en_ZA Stellenbosch University 141 pages : illustrations, maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Diamictites -- South Africa UCTD Sedimentary rocks -- South Africa Sedimentary basins -- South Africa Grobbelaar, Mareli A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa |
| title | A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa |
| title_full | A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa |
| title_fullStr | A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa |
| title_full_unstemmed | A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa |
| title_short | A comparison between diamictites at the Witteberg-Dwyka contact in southern South Africa |
| title_sort | comparison between diamictites at the witteberg dwyka contact in southern south africa |
| topic | Diamictites -- South Africa UCTD Sedimentary rocks -- South Africa Sedimentary basins -- South Africa |
| url | http://hdl.handle.net/10019.1/97091 |
| work_keys_str_mv | AT grobbelaarmareli acomparisonbetweendiamictitesatthewittebergdwykacontactinsouthernsouthafrica AT grobbelaarmareli comparisonbetweendiamictitesatthewittebergdwykacontactinsouthernsouthafrica |