https://commons.ru.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:2219 Wed 12 May 2021 23:24:45 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1541 Wed 12 May 2021 23:04:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5785 Wed 12 May 2021 22:17:34 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4927 75 million carats recovered at >95% gem quality) comprises onshore and offshore marine deposits that are developed within ∼100km of the Orange River outfall. For much of the Cainozoic, this long-lived fluvial system has been the main conduit transporting diamonds from kimberlitic and secondary sources in the cratonic hinterland of southern Africa to the Atlantic shelf that has been neutrally buoyant over this period. Highly energetic marine processes, driven in part, by southerly winds with an attendant northward-directed longshore drift, have generated terminal placers that are preserved both onshore and offshore. This study, through detailed field sedimentological and diamond analyses, investigates the development and mineralisation of gravel barrier deposits within the ancestral Orange River mouth area during a major ∼30 m regional transgression ('30 m Package') in the Late Pliocene. At that time, diamond supply from this fluvial conduit was minimal, yet the corresponding onshore marine deposits to the north of the Orange River mouth were significantly diamond enriched, enabling large-scale alluvial diamond mining to take place for over 75 years. Of the entire coastline of south-western Africa, the most complete accumulation of the '30 m Package' is preserved within the palaeo-Orange River mouth as barrier spit and barrier beach deposits. Arranged vertically and laterally in a 16m thick succession, these are deposits of: (1) intertidal beach, (2) lagoon and washover, (3) tidal inlet and spit recurve and (4) storm-dominated subtidal settings. These were parts of larger barrier features, the bulk of which are preserved as highstand deposits that are diamond-bearing with varying, but generally low grades (<13 stones (diamonds) per hundred tons, spht). Intertidal beach and spit recurve deposits have higher economic grades (12-13 spht) due to the energetic sieving and mobile trapping mechanisms associated with their emplacement. In contrast, the less reworked and more sandy subtidal, tidal inlet and washover deposits have un-economic grades (<2 spht). Despite these low grades, the barrier deposits have the largest average stone (diamond) size (1-2 carats/stone, cts/stn) of the entire Namibian mega-placer, given their proximity to the ancestral Orange River outfall. This study demonstrates that barrier shoreline evolution at the fluvial/marine interface was controlled by: (1) a strong and coarse fluvial sediment supply that sustained shoreline growth on a highly energetic coast, (2) accommodation space facilitating sediment preservation and (3) short-duration, high-frequency sea-level cycles superimposed on the∼30 m regional transgression, promoting hierarchal stacking of progradational deposits. During these sea-level fluctuations, diamonds were 'farmed' from older, shelf sequences in the offshore and driven landward to accumulate in '30 m Package' highstand barrier deposits. In spite of the large supply of diamonds, their retention in these deposits was poor due to an incompetent footwall of ancestral Orange River mouth sediment and the inherent cobble-boulder size of the barrier gravels. Thus the principal process controlling diamond entrapment in these barrier deposits was kinetic sieving in a coarse-grained framework. Consequently, at the marine/fluvial interface and down-drift for ∼5 km, larger diamonds (1-2 cts/stn) were retained in low-grade (<2 spht), coarse-gravel barrier shorelines. Smaller diamonds (mostly < I cts/stn) were rejected into the northward-driven littoral sediments and further size-sorted along ∼95 km of Namibian coast to accumulate in finer, high-grade beach placers (> 100 spht) where bedrock footwall promoted such high concentrations. The gravel-dominated palaeo-Orange River mouth is considered to be the ' heart' of the Namibian mega-placer, controlling sediment and diamond supply to the littoral zone further north. Although coarse gravel is retained at the river mouth, the incompetence of this highly energetic setting to trap diamonds renders it sub-economic. This ineffectiveness at the fluvial/marine interface is thus fundamental in enriching the coastal tract farther down-drift and developing highly economic coastal placers along the Atlantic coast of south-western Africa.]]> Wed 12 May 2021 20:08:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3859 Wed 12 May 2021 19:39:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4201 Wed 12 May 2021 19:25:43 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4419 Wed 12 May 2021 19:14:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3013 Wed 12 May 2021 18:37:06 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6039 Wed 12 May 2021 18:26:52 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4101 Wed 12 May 2021 18:21:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4355 Wed 12 May 2021 18:09:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3991 Wed 12 May 2021 17:52:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3318 Wed 12 May 2021 17:41:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2094 Wed 12 May 2021 17:14:13 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4338 Wed 12 May 2021 16:51:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5451 Wed 12 May 2021 16:24:52 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5825 Wed 12 May 2021 16:03:06 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:977 Wed 12 May 2021 16:02:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5762 Wed 12 May 2021 16:00:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4780 Wed 12 May 2021 15:48:13 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2377 Wed 12 May 2021 15:47:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4310 Tue 24 Aug 2021 16:28:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3025 40 years), which were then differentiated according to gender, reproductive status, and relationship status. Treating the interviews as jointly produced narratives, I analysed them by means of a performativity/performance lens. This dual analytic lens focuses on how particular narrative performances are simultaneously shaped by the interview setting and the broader discursive context. The lens was fashioned by synthesising Butler’s theory of performativity with Taylor’s narrative-discursive method. This synthesis (1) allows for Butler’s notion of “performativity” to be supplemented with that of “performance”; (2) provides a concrete analytical strategy in the form of positioning analysis; and (3) draws attention to both the micro politics of the interview conversation and the operation of power on the macro level, including the possibility of making “gender trouble”. The findings of the study suggest that the participants experienced difficulty narrating about male involvement in parenthood decision-making, owing to the taken for granted nature of parenthood for heterosexual adults. This was evident in participants’ sidelining of issues of “deciding” and “planning” and their alternate construal of childbearing as a non-choice, which, significantly served to bolster hetero-patriarchal norms. A central rhetorical tool for accomplishing these purposes was found in the construction of the “sacralised” child. In discursively manoeuvring around the central problematic, the participants ultimately produced a “silence” in the data that repeats the one in the research literature.]]> Tue 15 Aug 2023 16:06:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3949 Thu 13 May 2021 13:31:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6037 Thu 13 May 2021 07:39:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4777 Thu 13 May 2021 06:53:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4073 Thu 13 May 2021 06:37:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5760 Thu 13 May 2021 05:23:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4321 Thu 13 May 2021 05:22:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1855 Thu 13 May 2021 05:15:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3952 Thu 13 May 2021 04:58:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4204 Thu 13 May 2021 04:43:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4365 Thu 13 May 2021 03:50:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4369 Thu 13 May 2021 03:41:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2246 Thu 13 May 2021 03:08:52 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3035 Thu 13 May 2021 02:44:55 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5311 Thu 13 May 2021 02:41:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3967 Thu 13 May 2021 02:10:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27035 Thu 13 May 2021 02:03:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4372 Thu 13 May 2021 01:49:31 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3305 Thu 13 May 2021 01:47:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3299 Thu 13 May 2021 01:26:32 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5806 Thu 13 May 2021 00:46:22 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4593 Thu 07 Jul 2022 20:21:17 SAST ]]>