Talk:Lutetium–hafnium dating

Feedback from Tamjwh
Feedback on "Lutetium-hafnium dating":

Tamjwh (talk) 12:56, 18 October 2017 (UTC)
 * 1) Applications were clearly illustrated. However, it is suggested that a section on "further research directions" can be added to show the future potential development of earth sciences with the use of Lu-Hf dating.
 * 2) Formula were shown, but improvement can be made by suggesting what different ɛHf and CHUR model age values imply to allow the readers have a better idea of the their meaning. For example describing the ranges of values of ɛHf and the implications of its negative and positive values.
 * 3) Some technical terms require brief elaboration or links to make the overall logic flow clearer, e.g. incompatible trace elements, REE, cumulate protolith etc.

Feedback from xaviertang
Hi GeoJeremy, I appreciate your effort in putting equations on your pages, which has greatly enhanced the readers' understandings towards the content, notably readers in relevant field. But I think the importance of this method and comparison with other dating method could be mentioned in your content, as I would also like to know more about how this method is better than the other method and the reason of using this method. Just like the Nd-Sm system and U-Th-Pb system, as I know they could also tell the age of crust formation. If this method is more difficult and expensive to do, why do we bother use this method? Is this method more accurate? Or is this method capable to tell some unique things about the early Earth?

I also like the application part of the page, but it is quite short. I think you can elaborate more from that.

Hope you find my comment useful. — Preceding unsigned comment added by Xaviertang (talk • contribs) 08:48, 20 October 2017 (UTC)

Xaviertang (talk) 09:42, 20 October 2017 (UTC)

Feedback from kakitc
Your page is good and here are some suggestions:
 * As mentioned by xaviertang, you may add a comparison with other dating method, such as about age-range, advantages, disadvantages, minerals can be used, so that the reader can understand what is special for using these two isotopes for dating.


 * In section Age determination, you mentioned isochron can be plotted and the age can be obtained from the slope, I think you can add a figure showing how to read and plot the isochron.

Kakitc (talk) 08:05, 22 October 2017 (UTC)
 * In section Lu/Hf and Hf/Hf ratios of CHUR, you mentioned the discrepancies of 176Lu/177Hf and 176Hf/177Hf ratios, I think you can suggest some limitation to this method due to this problem, as well as some possible models to explain it. The figure is this section looks good but I think it is hard to relate it with the text.

Comments from Graeme Bartlett
Graeme Bartlett (talk) 00:15, 23 October 2017 (UTC)
 * Perhaps you could include an isotope chart that shows the direction of the decay, increasing in atomic number and decreasing neutron number (or the other direction for the other decay).
 * Also it would be good to include the half life and probability of this decay in the lead or introduction.
 * Try to avoid using technical abbreviations like CHUR. You can mention it once, but it is much easier to understand if you don't use it repeatedly.
 * Our readers may not realise that β− is the same as e−.
 * The formula for tCHUR appears wrong, with denominator = numerator.
 * Is there any accepted value for CHUR(0)? If so please include the value otherwise if it varies so much between measurements, there is no actual standard.
 * How uncertain are the results from this dating method?
 * Graphs showing the isotope ratios in the mantle and crust through time could add to understanding. (with uncertainty plotted).
 * More measurements and worked examples would be good.
 * How do U-Pb and Lu-Hf dates compare?
 * Stylistic comments: Try not to use math formatting for simple symbols: for your β− when I copy and paste I get this" "β − {\displaystyle \beta ^{-}} \beta ^{-}" but you can use the "β" unicode characters directly. The more complex formulae are OK with this formatting though.
 * Link chondrite solar nebula planetesimal.
 * Please put the references after the punctuation, that is after . :
 * Please add digital object identifiers to your references.
 * When you add the volume in a reference, don't type this: "volume=133(1)", as the issue number goes in a separate parameter. I ran citation bot on the page and it added some more values, but did not remove the  bits. Graeme Bartlett (talk) 00:15, 23 October 2017 (UTC)

Feedback from dinohk
1. While this is a very specific technical topic, I think you could still very briefly recap what radiometric dating is or at least provide a link to that page. Similarly it would not hurt to include links to some concepts like half-life.

2. I think that the equations should be explained in a bit more detail, especially for the Epsilon and CHUR model age.

3. Under applications you should provide some links to the relevant topics: petrogenesis, detrital zircon, etc. — Preceding unsigned comment added by Dinohk (talk • contribs) 04:11, 23 October 2017 (UTC)

Review from Jupiter
Hi GeoJeremy.

Your page gives a detailed explanation on Lutetium-hafnium dating with clear chemical formulas, mathematical expressions and an animation. Your structure is clear and well planned to first introduce the geochemistry, followed by dating principles and analytical methods and finally the application/examples, which is easy to follow and understand the logic.

Here are some suggestions:

1. The first thing comes to me on your page is the animation of elemental movement starting from planetesimal formation. It is an interesting animation and useful to present the idea. However, it may be better to label the the formation of earth solid surface (Black Circle), as the readers may not understand the sudden differentiation of the blue particles from the red and brown ones.

2. In the "application" part, you gives some examples of where this dating methods is applied, such as sandstones in the Oslo Rift. A picture showing the real places may make your example more lively and interesting. You can also show some picture of the minerals you mentioned in the text if possible. On the wiki page Radiometric dating, there is a picture showing the Ale's Stones at Kåseberga in the "Radiocarbon dating method" section, and a picture of apatite crystals in the "Fission track dating method" section.

3. In "Radiometric dating", you add a link as "See also: Isotopes of lutetium" below your subtitle "Decay of 176Lu". It is actually the main article of 176Lu instead of extra information, so you may want to replace "see also" by "main article".

4. You may add some links to the relevant topics, especially for the last section (such as detrital zircon).

5. As you have included equations (in particular those in the section of Epsilon and CHUR model age), they should be explained and defined more clearly. Other wiki pages about dating methods maybe a good reference. For example on the page of Lead–lead dating, all parameters are defined.

In short, your page provides a detailed and clear explanation. Some pictures, better labelled diagrams, more links and detailed defined equations may help to make it a better page. Jupmira104 (talk) 07:09, 23 October 2017 (UTC)

Feedback from kakitc
Your page is very concise! The following are some suggestions:
 * In figure from Rehman et al (2012), it is better to remove the original caption from the figure and put the text about it into the caption. The caption is too difficult for non-geology readers, the text discussing this figure is also too complicated. It needs more explanation on why εHf can be used to determine the sources of magma.


 * For the CHUR model age, it is better not to have a subheading the same as the heading. In this section, it mentioned about the discrepancies of the isotopic ratio among different type of chrondrites. Does it mean the CHUR model age derived from Lu and Hf are not accurate and not useful? Further explanations about the CHUR model age can be added.


 * I think you can add a section to briefly talk about the sources of errors and the suitable ranges of this method.

Kakitc (talk) 09:32, 20 November 2017 (UTC)

Feedback from Jupiter 20171120
Your page concisely explains the concept of Lutetium-hafnium dating with useful charts and images. I also found the figure from Rehman et al (2012) is a bit odd and unclear with the original caption on the image. But then I realized that is not your image uploaded, so you may want to fix it or just leave it. In the schematic diagram, it is good to indicated the black circle as solid Earth in the caption, compare to previous version. I saw you have put definitions of terms used in the equations (Epsilon and CHUR model age), which is much more clear.

Feedback from Wlamwk
Hi GeoJeremy:

1.	For the original figure from Debaille et al (2017) showing the example of Lu/Hf isochron, it may be better to have slightly more detailed caption e.g. indicating the linear relationship of the plot, etc. So, readers can associate the diagram with the text easier.

2.	You may add more blue links for the sub-sections Early Earth mantle-crust differentiation and Detrital zircon and provenance so that readers can refer to other wiki pages when they are unsure about the terms.

3.	You may consider adding a short section showing the sources of error and limitations or difficulties of using lutetium-hafnium dating method nowadays. Wlamwk (talk) 03:38, 21 November 2017 (UTC)

Review from Dinohk
I don't think you explained what Yb is in the radiometric dating section. It would be good to add a link or just quickly explain what it stands for.

You have a much better explanation of what Epsilon and CHUR model ages are than before but I think the Epsilon section could benefit from just a short explanation of what it is at the beginning of the section. — Preceding unsigned comment added by Dinohk (talk • contribs) 17:22, 21 November 2017 (UTC)

Review from eunicecyl
Hi, your page is super great and informative:) Just a few points u might want to change a bit

The figure 9 is quite awkward as mentioned by many. Maybe u would like to crop out the caption from the original pic and rephrase it ur own? It would be nice if u can include some limitations/source of errors of this dating method. And just a minor thing u might want to add: I think adding a figure or a diagram listing a few major dating methods and its decay constant should be useful in helping others to visualize the need for different dating methods. Eunicecyl (talk) 03:30, 22 November 2017 (UTC)