| Autor: |
Ntake, Mahlatse M., Malapana, Ronaldo, Sekantsi, Tsibula J., Maseko, Sibusiso, Teffo, Mokgadi K., Baiyegunhi, Christopher |
| Předmět: |
|
| Zdroj: |
Petroleum & Coal; 2023, Vol. 65 Issue 3, p946-966, 21p |
| Abstrakt: |
Grain size analysis is a vital sedimentological tool used to unravel the hydrodynamic conditions, mode of transportation and deposition process of detrital sediments. Despite the distinct stratigraphic sequence and lithological variation of the Ecca Group in the southern Main Karoo Basin, up to now, there is not much information on the grain size parameters of the sandstones. In addition, the few measured statistical parameters were not adequately related to the mode of transportation and deposition. As a result, a total of 35 sandstones from borehole KWV-1 were investigated for their grain size distributions. To unravel the transportation mechanisms, textural characteristics and depositional environment of the sandstones, grain size statistical parameters, binary plots, linear discriminant plots and Passega diagrams were used. The grain size parameters indicated that the sandstones were finegrained to very fine-grained and displayed near symmetrical patterns. The binary plots indicate that these samples were deposited mostly by wind (aeolian action) with a few deposited by other transportation mediums. From the Visher diagram, it is evident that the main transportation mode is saltation with a few sediments in suspension and traction. The Passega diagrams unravelled that there were fluctuations in energy levels, thus indicating that the samples were transported through rolling and suspension, saltation and graded suspension. According to the linear discriminant plots (LDF), the investigated sandstones are turbidity currents sediments. Furthermore, the LDF disclosed that the sedimentation process of the Collingham, Ripon and Fort Brown Formations occurred in shallow marine environments. Prince Albert deposits are indicated to be lacustrine-deltaic. These samples are further proven to have been deposited by tractive currents. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
