Talk:Carbonate compensation depth

CCD versus Lysocline - Clarification Sought

I'm no expert on any of this, what I know I can thank wikipedia's contributors for but what I would clarifying would be the relationship betweeen the lysocline and the CCD. If I've got this right the Lysocline has a clear definition as being the depth at which dissolution exceeds creation of Calcium Carbonate. The CCD seems a little more vague to me. Am I correct that the CCD is the depth at which no calcium carbonate can be found at all? If that is the case then this might vary not just due mainly to the temperature, pressure and pH of the water (as in Lysocline) but also the rate of sedimentation - perhaps as a product of the size of the creatures concerned. If this were the case then the CCD could be deeper for larger marine detritus because presumably it sinks faster (Stoke's law). Might it also depend on the amount and sizes of creatures above? When I looked at articles in wikipedia about PETM it mentions Lysocline (rather than CCD level) fluctuating geologically. That's confused me. [[1]] If CCD is a simple case of carbonate ooze "yes" or "no" then surely that is what is reflected in geological records rather than the Lysocline. If I am not just being dense can someone in the know please clarify this. --Andrew F. (talk) 23:01, 26 April 2011 (UTC)

Lemma-name wrong?

I think the whole lemma should be renamed to "Calcite Compensation Depth", as that's the correct term (this fact is support by encyclopaedia britannica: http://www.britannica.com/EBchecked/topic/88936/calcite-compensation-depth). This is especially important because carbonate would take both calcite and aragonite into account, which as we know do both have a different compensation depth. Therefor, and to prevent a mixup, one should use CCD for calcite, and ACD for aragonite. It could be useful to point that out in the article. I'd prefer to either put both aragonite and calcite into one article or, what i'd prefer, have two articles, one for calcite and one for aragonite, though I have to admit that it would derogate a quick overview about both topics. What do you think? --84.57.65.26 (talk) 03:01, 10 February 2010 (UTC)

This article says that "In the late Eocene the development of Antarctic glaciers resulted in colder deep sea temperatures leading to a deeper CCD." If the water temperatures are colder, wouldn't that lead to a shallower CCD since carbonate is more soluble?

The above comment seems to be correct. Although the CCD deepened during this period it was not for the reason given in the article. For example see this textbook. A Nature article by Tripati et al is precisely on the topic of late Eocene CCD change. They hypothesize that CCD deepening during this period was due to glaciation and the consequent sea level fall, which led to narrower continental shelves and greater direct input of carbonate into the deep ocean. However, Tripati et al then argue that later, at peak glacial conditions, a slower hydrologic cycle and reduced weathering decreased carbonate deposition and led to shoaling of the CCD. It might rather be that the hydrologic cycle is slowest (with respect to freshwater input to the oceans) at the maximum growth rate of the glaciers. At peak glaciation, no net water is being removed from the hydrologic cycle by glaciers. This line of thought requires a CCD deepening mechanism such as increased salinity and carbonate saturation state induced by the lower freshwater input.

Back to the topic at hand, because understanding of this unfortunately complex topic is tied up with understanding climate change and greenhouse/icehouse state change, it is important to be as straightforward as possible. I will edit the article with respect to the geologic history of the CCD. -ggp —Preceding unsigned comment added by Ggpauly (talk • contribs) 04:13, 1 May 2009 (UTC)

Why no article on carbonate compensation?

I went to Wikipedia to learn about the carbonate compensation process and this article was Wikipedia's first suggestion, which seems to be focused on one of its parameters, namely CC depth and its dependence on time and ocean depth. Isn't this a bit like an article on the integer zero without an article on the integers? And what about other parameters such as CC gradient, and other dependencies such as distance from significant littoral limestone deposits? Intuitively the high carbonate level at the surface of the ocean acts as a thin barrier to CO2; any holes in that barrier would create a conduit to the ocean bottom along which CO2 finds it progressively easier to dissolve with increasing depth. Would not the uniformity of that barrier therefore be critical to projections of the actual uptake (downtake?) of atmospheric CO2 by the ocean? Without a detailed picture of the whole carbonate compensation process, such projections would surely have to be pretty crude. --Vaughan Pratt (talk) 17:21, 25 November 2009 (UTC)

Ok, found it: Ocean acidification#Calcification, which seems more like the big picture of carbonate compensation I was looking for. Since that section contains links to both this article and the lysocline, I'll make Carbonate compensation a redirect to the calcification section. Sorry to be so slow. --Vaughan Pratt (talk) 17:44, 25 November 2009 (UTC)

Wiki Education assignment: Introduction to Chemical Ecology

This article was the subject of a Wiki Education Foundation-supported course assignment, between 23 August 2022 and 9 December 2022. Further details are available on the course page. Student editor(s): 許翠庭 (article contribs).

— Assignment last updated by 許翠庭 (talk) 20:03, 14 October 2022 (UTC)