Talk:Witwatersrand

message: There seems to be a lot of overlap between the two articles. Either some way of differentiating them needs to be found or they should be merged. It seems that they both refer to the same area, but I could be mistaken. 168.209.98.35 14:07, 28 January 2006 (UTC)
replies: text: No. I'd say this article should be redone to focus more on the physical geography, geology and important mining aspects while the urban and social geography stuff should go in the Johannesburg article. Just my take, as Witwatersrand means gold and geology to me :-) Vsmith 14:24, 28 January 2006 (UTC)
thread_title:  Merge with [[Greater Johannesburg Metropolitan Area]] 

message: This article could do with a map of the mountain range. It is very hard to find a solid definition of its location Park3r (talk) 14:02, 5 July 2013 (UTC)
thread_title: Map of the witwatersrand mountain range

message: I agree with the comments made in 2006, above, that an encyclopedic entry on the "Witwatersrand" should pay considerably more attention to the geography, geology and geological origins of this geological structure. It is true that the term "Witwatersrand" is also loosely used to refer to the towns and cities along the Witwatersrand ridge, centered on Johannesburg (as in "the PWV area" = "Pretoria, Witwatersrand and Vereeninging"). But that is just its colloquial. The term "Witwatersrand" is a geographic/geological term, and the article should concentrate and explain that, especially the origin of the gold ores. I will attempt to rewrite the article with this in mind. It can always be changed back, or improved if my editing is considered inappropriate or misleading. Oggmus (talk) 06:04, 3 February 2014 (UTC)
thread_title: More geology and geological origins needed

message: The Witwatersrand Basin article was very low on geological facts. I have used some of what I have written here to re-write that article. The geology of the part (Witwatersrand) is inevitably very similar to that of the whole (Witwatersrand Basin).Oggmus (talk) 14:47, 7 February 2014 (UTC)
thread_title: Use of some of this article's material in the [[Witwatersrand Basin]] article

message: Is there any source for a maximum altitude of 1913 metres of the Witwatersrand? I couldn't find any. Thanks in advance, --Vanellus (talk) 14:13, 25 February 2017 (UTC)
thread_title:  Maximum altitude 

message: It's hard to see what benefit there is for two articles with lots of copy-pasting. Content should probably be consolidated here, with a redirect from the other article. Park3r (talk) 13:24, 4 April 2018 (UTC)
replies: text: Klbrain (talk) 06:20, 25 September 2019 (UTC)
thread_title: Proposed merger with Witwatersrand Basin

message: A theory developed in the figure depicting an ashtray carved out of a soft form of banded ironstone clearly makes problem and is highly dubious. Hereafter, a copy of this figure and its problematic caption. 
It is clear that the red bands are richer in iron (III) oxides than the white (beige) bands and that there is an alternation related to the abundance of FeOOH or Fe2O3 in the sediments. This could be related to fluctuations in concentration of oxygen dissolved into water and maybe also related to the activity of Archaean photosynthesizing cyanobacteria producing this oxygen.
The precipitation of Fe2O3 is due to the oxidation of Fe2+ by O2 because of the difference of solubility between Fe3+ and Fe2+, this latter being about 100 times more soluble than the former one. The mechanism is correct, but not the ultra fast cyclic precipitation process and its short time scale claimed without any proof or argument. 
Indeed, the considered time scale of day/night alternance is much too short, or the day/night frequency too high. A precipitation rate of several millimeters per day for Fe2O3, or such a sedimentation rate, is considerable when considered at the geological scale. In the absence of reliable references source, it has to be considered as a pure speculation and an unproven theory, or a geological fantasy. It is perhaps a joke or the results of a vandalism of the page. One could also argue that the rotation rate of the Earth on its axis was much slower 3-2 Ga than today. The cause of this cyclic sedimentation is enigmatic and deserves a robust explanation. "Strong claim requires strong evidence" as often repeated by Carl Sagan. What is the evidence to support a day/night cycle? How to determine that? Another explanation is that the Fe2+ concentration in the water was fluctuating for another unknown reason, not the O2 concentration. Thanks for a convincing explanation supported by strong evidence. Shinkolobwe (talk) 22:02, 12 February 2021 (UTC)
replies: text: 2021-02-13: Correction of this fancy and erroneous explanation on the diurne cyclic character of sedimentation of the colored iron bands. No, the beige bands did not sediment during the night. It would imply a much too high sedimentation rate. This makes no sense. There is a confusion between two clearly distinct processes occurring at very different rates and time scales: chemical precipitation of  (very fast)  and geological sedimentation (slow). The time constant of photosynthesis cycles (day and night) is much faster than that of sedimentation (a slower process) and is hidden in the red bands. Sedimentation occurs on a much longer time scale, even if iron oxides were perhaps preferentially precipitated during the short period of daylight because this precipitation reaction is relatively fast. And finally, how to discern days and nights in very ancient sediments after more than 2 billion years. Shinkolobwe (talk) 13:20, 13 February 2021 (UTC)
thread_title:  Geological origin 

message: I apologize, we both seem to be misreading each other's edits. Mine purely referenced the comma versus space in 40000 and yours referenced the duplicate "most". All I could see that was different was that you'd inserted a comma whereas there was none before, and I missed that there was a "most most". I've tried to sort out both errors. Avi8tor (talk) 08:24, 4 May 2022 (UTC)
replies: text: Hi Avi8tor no worries, and thanks for the apology - Arjayay (talk) 10:25, 4 May 2022 (UTC)
thread_title:  Misreading our edits.