text:
Columnist: Dr Prince Hamid Armah
Making Ghana a mathematics-friendly nation; a key to our national development agenda
In November 2019, the United Nations Education, Scientific and Cultural Organisation named March 14, of every year as the International Day of Mathematics. This was in recognition of the central role Mathematics has in our lives. Prior to that, the day had been celebrated as World Pi Day, after the famous mathematical constant, the first three digits of which are 3.14. In the American rendering 3.14 is March 14 hence the choice of that date.
The date also has great significance for two of the most celebrated figures in science. On 14th March, 1879, Albert Einstein was born. Just twenty-six years later, the publication of his Annus Mirabilis papers changed physics and altered how we conceive light, matter, time and space. It is also the date on which another giant of science died. Professor Stephen Hawkins' research on black holes and the big bang tremendously expanded our understanding of the universe.
The term mathematics derives from the Greek word "mathema" which means "knowledge," an indication of the centrality of the subject to all scholarship. The study of mathematics is essentially a study of four major related concepts. We study numbers and how things can be counted; structure or how things are organized (algebra); where things are and how they are arranged (geometry); or how things change or become different (analysis).
The study of mathematics helps develop essential skills that are useful for living life meaningfully. These skills include creativity, critical and spatial thinking, investigation and problem solving and the ability to grasp abstract concepts. Without mathematics, our lives, I daresay, would be journeys from chaos to catastrophe with no sense of the distance between them and no conception of the magnitude of these disasters.
For the first commemoration in 2020, UNESCO chose the theme "Mathematics is Everywhere". This year, it has chosen "Mathematics for a better world". Both themes show how mathematics is suffused into the humdrum of our daily lives.
When we think of professions that rely on the subject, we tend to think of engineers and scientists. But mathematics is useful to a lot more of us. The seamstress cannot cut her patterns without mathematical concepts such as measurement. The fishmonger cannot sell his produce without mathematical concept of arithmetic. At home, we could not serve our potions of food if we didn't employ mathematics. In politics, we could not determine the winner of an election, or which side in parliament is the majority without mathematics.
Owing mostly to challenges with the mode of instruction and assessment, many children come to view mathematics as a difficult subject. This directly affects the number of people willing to take it up as a discipline in later life. This, in turn, affects the number and quality of personnel available to careers and disciplines that rely on mathematics and its applications.
When one surveys the broad spectrum of innovation and technological advancements that now define our very lives, we can see the fascinating hand of mathematics guiding all of them. From the inexhaustible store of knowledge that is google, to the wonders of artificial intelligence, we see the transformational effects of applied mathematics. Mathematics has been key in the efforts to sequence the Coronavirus, as our own scientists at Noguchi did last year. This has helped in understanding the nature of the virus and in developing the vaccines and therapeutics that are helping save lives.
Unlike their counterparts in countries such as Korea, Japan and Singapore, Ghanaian children struggle to demonstrate a conceptual understanding of basic mathematical principles. The manner of instruction and assessment, it has been found, focuses on the memorization and recitation at the expense of problem solving and application of mathematical knowledge to everyday contexts, which are the true values of studying mathematics.
International comparative studies, such as the Trends in International Science and Mathematics Study (TIMSS) have consistently shown Ghanaian pupils performing poorly, with over eighty percent unable to meet basic benchmarks of mathematical competence. The Ghana National Education Assessment of 2016 showed that less than 25 percent of Ghanaian pupils met the proficiency cut-point in P4 and P6 mathematics. A review of Ghanaian pupils' performance in mathematics tests revealed that they are quite comfortable with computations and algorithms. Unfortunately, they are unable to apply the principles of these operations to mathematical problem solving.
This has been attributed to factors such as inadequate teaching and learning materials as well as insufficient instructional time. Also to blame are an overcrowded curriculum and the poor training of teachers. We can resolve most of these by applying more resources and changing the nature of curriculum, instruction and assessment.
A study by S.D Gyang, "Mathematics Education in Proposed Junior Secondary School in Ghana" found that the manner of instruction of mathematics discouraged students. Many of us would recognize the phenomena described in the study such as the early morning drills known as "mental" that often led to painful punishments for erring students. It is no wonder that many of us have less than fond memories of the subject and why so few, some four decades after the study, are still wary of taking up this necessary challenge.
Central to our efforts to bring mathematics into the mainstream where it should be, would be an overhaul of the way in which the subject is taught. I am happy to observe that we are making some efforts in that direction. As former Director General of the National Council for Curriculum and Assessment, I can report that the new standards-based curriculum that we developed and is currently in operation, directly addresses this problem. And as someone whose first love was and is mathematics, I take particular pride in this fact.
I am also heartened by efforts that the government is making to improve the teaching and learning of mathematics in the country. Through the Science, Technology, Engineering, Art and Mathematics Centres, the national numeracy programme in collaboration with Matific and other technology-based initiatives such as iBox, the Ministry of Education is working to make the study of mathematics more fun and attractive to students. In addition, the Mathematics and Science for Sub-Sahara programme by the World Bank, which Ghana has signed on to, will help improve teachers' content knowledge, pedagogical practices and the use of teaching and learning materials to boost children's understanding of mathematical concepts.
It is not as if we do not have the talent. Only last year, Roni Adom Edwin, a seventeen-year-old Ghanaian, won bronze at the annual Mathematical Olympiad, where he was also the highest scoring African student. It is our hope that Mr Edwin and other prodigies like him will come to walk in the shoes of our pre-eminent mathematician, the late, great and celebrated Professor Francis Kofi Ampenyin Allotey.
In his storied life and career, Professor Allotey came to exemplify excellence in the discipline not only here in Ghana but around the world. From relatively humble beginnings in Saltpond in the Central Region, he rose to the very top of his field. He was the first Ghanaian to become a full professor of mathematics, head of the Department of Mathematics and later Dean of the Faculty of Science at the Kwame Nkrumah University of Science and Tehnology.
He became famous for the "Allotey Formalism" which arose from his work on soft X-ray spectroscopy. Professor Allotey helped bring computer education to the masses around Africa. In 2004, he was listed among 100 physicists and mathematicians cited in the book, "One hundred reasons to be a scientist," the only African to make the list.
Indeed, Professor Allotey and his globally renowned exploits are a shining example and encouragement to all our young people, no matter the discipline that they choose to apply themselves to. In seeking to improve our participation and performance in mathematics, the late professor's distinguished career will be a necessary part.
That is why today, I am calling for Ghana to name 9th August, the date of his birth, as National Mathematics Day, in honour of his unbelievable achievements and also as a challenge and encouragement to young talents in the country to reach for similar accomplishments. In doing this, we will be celebrating a true national hero while sowing the seeds for the growth of his successors.
Mathematics is as central to the course of development as it is in our personal lives. We can guarantee our prosperity as a nation by investing in mathematics, improving the teaching and learning of it and assisting those who want to make a career in it.
A generation from now, we could be in the midst of a boom in innovation and enterprise, birthed by a revolution in mathematics. That future is ours to reach for. It is one we must aim for. And it is a future that I hope we can start to prepare for from today, as we mark the International Day of Mathematics.
The writer is the Member of Parliament for Kwesimintsim and the former Director-General of the National Council for Curriculum and Assessment. He holds a PhD in Mathematics Education and has over a decade of experience teaching mathematics


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Our Life-saving Programmes
Paediatric AIDS Fund (PAF)
The Paediatric AIDS Fund (PAF) is a special assistance scheme that provides a monthly allowance of RM100 to 100 underprivileged children aged 12 years old and below living with HIV or born into HIV-impacted families with a combined household income of less than RM2,000. The scheme is intended to alleviate the burden of living with HIV and enable the beneficiaries to lead healthy lives.
PAF recognises that children living with HIV/AIDS have immediate needs that require immediate solutions. Through this scheme, some of the urgent and basic needs are met to help the children and their families cope with their problems. Financial assistance will give them access to treatment as well as to meet their basic necessities such as food, clothing and school expenses.
• GlaxoSmithKline Pharmaceutical Sdn Bhd
• MyKasih Foundation
Click here if you wish to apply
Click here if you wish to donate to PAF
PAL Scheme
The PAL Scheme, which was launched in 1998, provides free second-line medication to underprivileged Malaysians living with HIV the opportunity to undergo Antiretroviral Therapy (ART) with the objective of helping them to prolong and improve their quality of life.
Patients who require second or third-line medication due to advancing disease progression are currently not supported by the government. The situation is especially dire for patients from poor household income who would default on their treatment simply because they can't afford to buy the medication that runs into thousands of ringgit per prescription.
To date, PAL has supported approximately 125 underprivileged PLHIV in Malaysia to have continuous access to medication and a second chance at life.
• Sime Darby Foundation
MyLady Assistance Scheme
The MyLady Assistance Scheme is a special empowerment programme that provides women living with HIV from underprivileged background the much-needed break and opportunity to help themselves.
The focus of the scheme is to aid women and single mothers living with HIV by equipping them with the knowledge and skill sets to start small-scale businesses and also refer them for suitable jobs with peer support programme. The scheme also offers zero interest micro-credit loans of between RM 5,000 and RM 10,000. The ultimate aim of the programme is to put these women on the right path to self-reliance and greater financial independence.
• Berjaya Corporation Berhad
• Ministry of Women, Family and Community Development
Special project in Sabah: SAGA Health Access Programme (SHAPE)
SAGA Health Access Programme (SHAPE) was introduced by Malaysian AIDS Foundation and our Partner Organisation, the Sabah AIDS Awareness Group Association (SAGA) in 2018 with the aim of helping underprivileged patients from Sabah rural interior to access treatment. A pilot project was successfully launched in in Sandakan and has since benefited more than 60 beneficiaries. The programme awards cash incentive to qualified beneficiaries to help to cover the high cost of travelling and other logistic expenses related to their hospital appointment in town.
Special Project in Sarawak: Teratak Kasih Tok Nan
Support by MAF is also extended to Sarawak through collaboration with the State Government of Sarawak with the establishment of Teratak Kasih Tok Nan, a halfway home for People Living with HIV, named after Sarawak's fifth Chief Minister, the late YAB Datuk Patinggi Tan Sri Datuk Amar Haji Adenan Satem.
Teratak Kasih Tok Nan provides overnight lodging facility as well as travel subsidy for underprivileged HIV patients to ensure that they continue to get the care and treatment they need. The home is operated by our partner organisation in Kuching, Sarawak AIDS Concern Society.
HIV patients in Sarawak, especially those from the rural hinterlands, have to travel far to seek treatment. Some have to journey more than 12 hours just to access treatment which result in many being discouraged from seeking treatment. Having this halfway home ensures the continuous flow of patients seeking treatment in Sarawak.
The Centre enjoys the patronage of YBhg Datin Patinggi Datuk Amar Hajah Jamilah Haji Anu, who continues to carry on her late husband's work to help Sarawakians living with HIV, especially women and children, in getting access to treatment, care and support.
Shelter Care for People Living with HIV
The Malaysian AIDS Foundation funded, and in some cases, helped to set up a number of shelter home facilities for People Living with HIV in Malaysia who are often bereft of any support from their family members or friends. They also face unbearable stigma and discrimination from their surrounding community and society at large.
Our shelter home is the place where they seek refuge as we provide them with a residential setting conducive for emotional and physical well-being. Services provided include basic nursing care, palliative care, medical referrals and bereavement counselling, psychosocial as well as spiritual support service.
The lists of shelters that have received direct funding from MAF are:
• Rumah Sahabat, Kota Bahru, Kelantan
• Faith Home, Kuala Lumpur
• PKKUM Shelter, Kuala Lumpur
• Rumah CAKNA Terengganu
• Rumah WAKE
Some of the shelter homes also support children living with HIV. They basically spend their entire childhood there and know of no other life outside the shelter.

redpajama_set_name: RedPajamaCommonCrawl


Chevrolet's® 50th Anniversary Camaro® is striking to look at and a thrill to drive. Now, courtesy of the Kats at AMT, you can enjoy a similar thrill, building a beautiful 1/25 scale replica of this modern muscle car right at your workbench! Created from all-new, modern tooling, this incredibly detailed kit features over 20 parts in the rear suspension alone! The rest of the kit ain't bad either! It's authentic through and through, scaled from factory CAD data. Build your muscle (car) with AMT!
Special 50th Anniversary parts - wheels, chin spoiler and grille!


← RECIPES TO COOL A BLISTERING HEAT CONTEST!
I am continuing to share parts of my WIP, Tangled Redemption, book 4 in the Celestial Surrender series. I still don't have a blurb;). My heroine is Sydney. We meet her for the first time in Tangled Hunger, book 2 of the Celestial Surrender series. Circumstances I cannot go into without spoiling everything result in her being kidnapped by a Vampire who has the impossible task of balancing the survival of one with that of a galaxy. I just realised I never mentioned the second Vampire who gets thrown into the equation and tries to find his place with these two. I will try and show Jayden soon. I may have to change his name as it's pretty close to Sydney.
This snippet is a rewrite from last week. Miguel pushed Sydney hard to kill the third Feral, basically leaving her unprotected, which makes no sense as his boss ordered him to kidnap her. Going by your feedback as well as my critique partner's I tried to rework and explain. The scene starts in Miguel's point of view.
"Miguel scrutinized the Naema before him. She was tall, only a little shorter than his six-three, and very slender, but not fragile. No, her body was tightly muscled and her Naema heritage gave her additional strength. Her blonde hair was cut pixie short and her aquamarine eyes carried darkness.
I am so deep in the editing cave I can't even see the light. I will do my best, but it may be later in the day before I can make my rounds.
Posted on August 10, 2014, in Uncategorized. Bookmark the permalink.	20 Comments.
I like her description. Nice to see a heroine who is not fragile.
I really like the way you described her eyes.
The reasoning seems sound…but still, she's to be prisoner. Good thing she's strong!
Yes, I like this. Keeps us more grounded in the moment. Have fun in the cave. That's where I should be right now but the siren call of networking is hard to resist.
Lol, it was pretty long slog in the cave and I am about to jump back in when I get home from work. Good luck with yours and thank you for coming by when time is precious.
I think 'take' should be 'taken' but other than that I like this a lot. His reluctance comes through really well, making him seem dangerous but still sympathetic.
I will check my grammar;). Thank you!!
Good luck in the writing cave. I liked the excerpt, this seems like a very high stakes situation and I can't wait for more details!
Thank you. I am glad it's working. I finished the second round of edits after 13.5 hours non-stop. Now I have one more round to go:).
OMG, I went a little made after hour 10;).
I completely get his motivation here, so I think your edits work. And now the reader knows somethings he doesn't, which is always fun!
You might consider if you can shift one of the 'was' sentences in the first paragraph to another verb–hard with description, but possible–because you have three in a row.
Sounds like more than a smidgeon of tension.
That means I've reached my goal! Thank you:).
Your description of the Naema makes her seem very real and really piques the interest. Well done.


From our offices in Greensboro, we provide skilled and knowledgeable legal services for immigrants and their family members. Our legal team is dedicated to helping you work toward your goals and to obtain the best possible results in your case.
Our firm is conveniently located in the heart of Greensboro, within a mile of J. Douglas Gaylon Depot, Greensboro College and Weaver Academy.
From the north: Take US-29 S to the exit for E. Gate City Blvd/E. Lee Street. Turn right onto S. Elm St. Turn left onto Smothers Pl. Turn left onto Spring Garden St. Our office is on the left.
From the south: Take I-73 N/I-74/US 220 N. Keep left to continue on Freeman Mill Rd. Take the McGee St. exit from Freeman Mill Rd. and turn right onto Blandwood Ave. Turn right onto Spring Garden St. We are located on the left.
From the east: Take I-40/I-85 S. Take exit 224 to merge onto E. Gate City Blvd/E. Lee St. toward US 29 N/US 220 N. Turn right onto S. Elm St. Turn left onto Smothers Pl. Turn left onto Spring Garden St. We are located on the left.
From the west: Take I-40 E to Freeman Mill Rd. (exit 218B). Take the McGee St. exit from Freeman Mill Rd. and turn right onto Blandwood Ave. Turn right onto Spring Garden St. and our office will be on the right.
If you need legal help with an immigration matter, speak with us. Contact our firm online or call 877-781-8091 to schedule an initial consultation to discuss your situation.


Somewhat of a follow on to my previous post about the WPServer Demo.
Ask 37signals: Is it really the number of features that matter?
Good software is about balancing value and screen real estate and understanding and outcome. If it takes 20 good features to get there, then great. If it only takes eight, even better. It's not the number that counts, it's the balance.
That is what I'm talking about here. The kitchen sink is wonderful, but too many times it is thrown at users who have to fight though all the tools to use just basic tasks. That is what really catches my eye about the WPServer Demo.
Also I'm not saying get rid of the kitchen sink either, it just isn't needed by everyone.


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College Grove, TN
This is a small community in a single neighborhood. As throughout the site, some neighborhood-level data are reserved for subscribers.
1 Alert
College Grove Profile
College Grove is a somewhat small town located in the state of Tennessee. With a population of 6,894 people and just one neighborhood, College Grove is the 110th largest community in Tennessee.
College Grove home prices are not only among the most expensive in Tennessee, but College Grove real estate also consistently ranks among the most expensive in America.
Occupations and Workforce
Unlike some towns where white-collar or blue-collar occupations dominate the local economy, College Grove is neither predominantly one nor the other. Instead, it has a mixed workforce of both white- and blue-collar jobs. Overall, College Grove is a town of managers, sales and office workers, and professionals. There are especially a lot of people living in College Grove who work in management occupations (20.75%), office and administrative support (16.19%), and sales jobs (9.29%).
Telecommuters are a relatively large percentage of the workforce: 10.28% of people work from home. While this number may seem small overall, as a fraction of the total workforce it is high relative to the nation. These workers are often telecommuters who work in knowledge-based, white-collar professions. For example, Silicon Valley has large numbers of people who telecommute. Other at-home workers may be self-employed people who operate small businesses out of their homes.
Setting & Lifestyle
College Grove is a good choice for families with children because of several factors. Many other families with children live here, making it a place where both parents and children are more likely to develop social ties with other families. The town's good public school district and large population of college-educated adults provide an environment conducive to academic success. Many people own their own single-family homes, providing areas for children to play and stability in the community. Finally, College Grove's overall crime rate is lower than average for the country.
One downside of living in College Grove is that it can take a long time to commute to work. In College Grove, the average commute to work is 34.41 minutes, which is quite a bit higher than the national average.
College Grove is a small town, and as such doesn't have a public transit system that people use to get to and from their jobs every day.
College Grove Demographics
The education level of College Grove ranks among the highest in the nation. Of the 25-and-older adult population in College Grove, 41.37% have at least a bachelor's degree. The typical US community has just 21.84% of its adults holding a bachelor's degree or graduate degree.
The per capita income in College Grove in 2010 was $50,444, which is wealthy relative to Tennessee and the nation. This equates to an annual income of $201,776 for a family of four.
The people who call College Grove home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of College Grove residents report their race to be White, followed by Black or African-American. Important ancestries of people in College Grove include English, Irish, German, French, and European.
The most common language spoken in College Grove is English. Other important languages spoken here include Italian and Polish.
44 Vital Statistics. 10 Condition Alerts found.
AGE OF College Grove, TN HOMES
TYPE OF College Grove, TN HOMES
SIZE OF College Grove, TN HOMES
136 Vital Statistics. 1 Condition Alert found.
Employment Industries in College Grove
in College Grove
in Tennessee
College Grove VIOLENT CRIMES
College Grove Property CRIMES
District Quality Compared to Tennessee
Better than of TN school districts.
ECONOMICALLY DISADVANTAGED 0.0% 0.0%
FREE LUNCH ELIGIBLE 0.0% 0.0%
REDUCED LUNCH ELIGIBLE 0.0% 0.0%
Nashville-Davidson--Murfreesboro, TN Metro Area regional investment potential
Housing Affordability Trends: Nashville-Davidson--Murfreesboro, TN Metro Area
Popular real estate near College Grove
Franklin, TN (Bingham / Parry)
Franklin, TN (Champions Cir / Champion Cir)
Franklin, TN (Epworth / Harpeth)
Franklin, TN (Lewisburg Pike / Donelson Creek Pky)
Franklin, TN (Mudsink)
Franklin, TN (Murfreesboro Rd / Riverside Dr)
Franklin, TN (West Harpeth / Douglas)
Murfreesboro, TN (Patterson / Salem)
Nolensville, TN (Arrington / Clovercroft)
Spring Hill, TN (Columbia Pike / Buckner Rd)
89% Match ‐ Thompson's Station, TN
89% Match ‐ Fairview, TN (Fernvale / Brush Creek)
88% Match ‐ Eagleville, TN
86% Match ‐ Nolensville, TN (Arrington / Clovercroft)
83% Match ‐ Rockvale, TN


This is one of my favorite puzzles. I have a few others that I wish to build someday, but this one must come first. Many of my favorite puzzles came from my Paternal Grandfather, but this one I discovered at the Science Museum in Seattle, WA.
I have to admit that I tried to solve it several times while visiting the museum with my children, but eventually I saw someone solve it. So I discovered the solution without beating it myself, but it is a great challenge and I wish to share it with others.
Please utilize what you have on hand. Spare wood, 3D printer, cardboard, plastic, kite string: it doesn't matter.
I personally used some spare wood from my shop, 550 paracord, and some rings from my daughter's jewelry kit. Initially I was going to design and 3D print this project on a smaller scale, but instead it can be created in minutes with the right tools and some scrap lumber.
I used a miter saw and a drill, some screws, plastic rings and 550 paracord.
I will supply the dimensions of my project, but again you can change it up to accommodate for the supplies that you have on hand.
It can be hazardous to use the recommended tools. I am laughing as I write this only because I hurt myself tonight working on this project. I was wearing flip flops and dropped a drill on my foot drill bit side down. I tore myself up pretty good. Please use caution and wear proper foot wear at all times. Also hearing protection, gloves and other PPE.
I used a 1" x 7" base that is 19.5 inches long.
1 top piece that is 1" x 3" and 18 inches long.
The center hole is cut with a spade bit that is 5/8". I tried a 1/2" spade bit initially, but I found it a bit tight for this puzzle.
I cut a 35" piece of paracord and used some 3/4 inch diameter rings to attach to the cord.
After you have cut your support pieces to length you can assemble them as seen in the photos. Drill your holes as recommended. A 5/8 inch hole near center on your top piece and a couple of holes down through the top piece that are large enough for your paracord to pass through. See photos as to placement and how to tie the rope.
There are two rings separated by a knot in the middle. Your goal is to pass one ring from one side over to the other side so that both rings are on the same side of the knot.
I am not going to post the solution with this instructable only because I am disappointed that I witnessed someone solve it before I could figure it out. I will post a video edit to this instructable on the last day of September 2016 showing the solution. If you feel you need the solution before that date please send me a comment and I will supply the answer.
Good luck and happy solving to you.
Do not watch the video if you want to solve on your own. Attached is a video of my son showing how to solve the ring puzzle.
is the ring bigger than the center hole?
Great question. Yes the rings are larger than the hole. They can't be too large, but need to be bigger than the center hole.
would you be able to fix the video explanation as it doesn't work for some reason. I'm definitely going to make this but the solution will help me with my own design.
I can also probably put the solution into words that would make sense if you want me to go that route.
I'm in no real hurry so when you can get around to it. If you can send the video to me via Google drive for large files that would also work.
I replaced the video, but the new video failed too. The original was working when I added it. I can email the video to you with wetransfer, but with my remodel job I do not have time to dig into why the video is failing on the Instructable right now.
I have a new program that allows me to transfer large files from my phone. So let me see what I can do. I am remodeling a kitchen right now, but I will try to get something up in the next couple of days.
Did you mean to say 3/4 " DIAMETER rather than circumference?
I will fix it tomorrow. Thank you for bringing this to my attention.


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Q: Kendo UI grid - programmatic update to auto-generated textbox I think one of my problems is similar to another Stack Overflow question, but not exactly, and this is fairly complicated to explain, so I have a lot of detail, but I think might be straight-forward to answer.  And because there might be other ways to do this than my approach, I'm, of course, open to suggestions.  Say I have this in a Kendo grid, in the HTML markup as seen after it renders:

            <input type=textbox data-bind=value:Status jQuery123456789="136" data-val="true" kendoBindingObject="[object Object]" />

        ....... // other columns in my grid, here

And I need to find out what "jQuery123456789" really is. It can be ANY number, because this textbox is auto-generated by a Kendo UI grid control that has inline editing.  I'll explain in a bit why I think I might need this attribute name.
This is how I'm getting to the textbox - a function that runs from an onclick event on an anchor tag (link button, essentially) that was in that first column before the Kendo control re-wrote the column dynamically to insert its textbox.  I pass in the ID of that row and get the textbox, and assign an ID to the Update button for later:
function btnClick(id) {
    $('id="btnEdit_'+id+'"]').click(); // programmatic click to Edit button I'll hide, later, that exposes the textbox
    var activeRow = $('[id="activeRow_"'+id']'); // gridrow "TR" element
    var activeElem = activeRow.children(0).children(0); // <-- textbox node

    activeRow.childNodes[4].childNodes[0].setAttribute("id", "btnUpdate_" + id); // sets ID on Update button for later jQuery clicking
    ....
}

In that ... area, above, I then also add a dropdown to the 1st column, dynamically, as the TD's 3rd node (2nd node is the field-validator for the textbox I didn't show). I have it in this format below just for display purposes, but in the code it is all on one line, inside activeRow.children(0).append() :
'<select id=ddlStatus_'+id+' onchange=setVal(this.value)>
    <option value=1>Active</option>
    <option value=0>Inactive</option>
    <option value=2>Cancelled</option>
</select>'

I then have it use the textbox's value and set the selected value on the dropdown with .val().  The onchange setVal() will programmatically update the textbox with the dropdown's new value, then I have it programmatically click the Update button with $('id="btnUpdate_'+id+'"]').click(); in the setVal() function.
The problem is that the update to the database does not happen.  If I comment out the programmatic update click, click into the textbox, hit the spacebar, click off of it, then click the Update button, then it will work fine.  I tried adding a .blur() on the textbox in setVal(), but no dice, and adding something like SendKeys is probably not an option as they scrutinize add-ons unless typed up by hand, directly.  Code resides on a non-internet connected network.
So I was thinking that in the ... area is where I need to update the dropdown with the textbox's attributes - that maybe if I copied the textbox's attributes and apply them to the dropdown, maybe then it will update the database, because of the user interaction with that control that it wants.  I can't leave it as a textbox because users won't know the value to input for these 3 possible values and if they enter a string, it will fail since it is expecting a number.  I really don't want to have to tack on validation for something that is already user-unfriendly.
So, to use the dropdown like I think I need to, I need the attributes of the auto-generated textbox.  But to get that "jQuery" attribute name, I need to do a partial match on the NAME, not its value, so I can set both on the dropdown.
I tried this:
var jQAttrName = activeElem.filter(function() {
    for (var property in $(this).data()) {
        alert(property);
        if (property.indexOf('jQuery') != -1) {
            return property;
    }
});

The only property it finds is "bind", not "data-bind", and definitely nothing with "jQuery" in it.  Has anyone done a programmatic update like this before, or matched on a partial name of an attribute, and gotten the full name, and then successfully gotten a programmatic update to work on a Kendo grid?
JSFiddle for getting the textbox attributes:  http://jsfiddle.net/vAk52/1
UPDATE:  This might be a simpler question, how can I get something like this to work to update the datasource, and then use remote data/AJAX and MVC?
New JSFiddle:  http://jsfiddle.net/4VMJE/

A: It turns out that I didn't have to get the "jQuery####" attribute on the textbox, or even use a textbox, at all, and could replace it using an EditorTemplate that would have the dropdown I needed.  So under "Views", in a "Shared" folder, I have an "EditorTemplates" folder and created a View inside called "StatusComboBox.cs" with a Kendo DropDown in it:
@(Html.Kendo().ComboBox()
    .Name("Status")
    .DataValueField("Value")
    .DataTextField("Text")
    .BindTo((System.Collections.Ienumerable)ViewData["status"]))

Next, we have a model called SimpleListItem:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace OurProject.Models
{
    [Serializable]
    public class SimpleListItem<T>
    {
        public T Value { get; set; }
        public string Text { get; set; }
    }
}

Then, in the controller, we put in these:
private void populateData()
{
    using (var db = new OurDatabase(false))
    {
        var statusList = new List<SimpleListItem<int>>();
        statusList.Add(new SimpleListItem<int> { Value = 0, Text = "0 - Inactive" });
        statusList.Add(new SimpleListItem<int> { Value = 1, Text = "1 - Active" });
        statusList.Add(new SimpleListItem<int> { Value = 2, Text = "2 - Cancelled" });

        ViewData["status"] = statusList;
        ViewBag.jsonStatus = JsonSerializer.Serialize(statusList);
    }
}
public class JsonSerializer
{
    public static T Deserialize<T>(string s);
    public static string Serialize<T>(T o);
}

... and put populateData() in here, in the Controller...
public ActionResult Index()
{
    populateData();
    return View();
}

And in the view, I had this for the column:
columns.Bound(p => p.Status).Title("Active").Width(65).ClientTemplate("# if (Status == 1) {#  #} else if (Status == 0) {#  #} else if (Status == 2) {#  #}#").EditorTemplateName("StatusComboBox");

You'll notice that this column effectively has a linkbutton with the  and  inside, which is set based on the value coming back from the database -- either a checkmark image for "1", or "x" for "0" or "2".  Clicking the "button" exposes the dropdown by programmatically clicking the Edit button.  I do this by setting an ID on the hidden Edit button:
columns.Command(command => {command.Edit().HtmlAttributes(new { id = "btnEdit_" + "${Id}" }); }).Width(100).Hidden(true);

then calling .click() in the checkmark's/X's onclick function, changeImg().
Requirements were to
  1) set the value when the dropdown was changed, and
  2) ensure no other fields were editable
This is the onclick function for the linkbutton in the first column:
function changeImg(obj, status, id) {
    var parentTr = obj.parentNode.parentNode;
    $('[id="btnEdit_'+id+'"]').click(); // Edit button clicked to expose dropdown
    parentTr.childNodes[4].childNodes[0].setAttribute("id", "btnUpdate_"+id); // this represents 5th column, first node in the cell - and sets an ID on the button for jQuery

    // Get values and make them read-only - remember, columns start at 0 where linkbutton is
    parentTr.childNodes[1].childNodes[0].setAttribute('id', 'titleCtrl'+id);
    parentTr.childNodes[2].childNodes[0].setAttribute('id', 'startDateCtrl'+id);
    parentTr.childNodes[3].childNodes[0].setAttribute('id', 'endDateCtrl'+id);
    var titleCtrl = $('[id="titleCtrl"+id]');
    var titleVal = titleCtrl.val();
    titleCtrl.css('display', 'none').parent().html(titleVal);
    var startDateCtrl = $('[id="startDateCtrl"+id]');
    var startDateVal = startDateCtrl.val();
    startDateCtrl.css('display', 'none').parent().html(startDateVal);
    var endDateCtrl = $('[id="endDateCtrl"+id]');
    var endDateVal = endDateCtrl.val();
    endDateCtrl.css('display', 'none').parent().html(endDateVal);

    // Click the button after update
    var statusField = $('input[name="Status_input"]');
    statusField.blur(function() {
        $('[id="btnUpdate_'+id+'"]').click();  // performs update here
    }
}

Note that "changeImg()" is sort of a misnomer -- the code doesn't flip the image from a checkmark to an X directly - updating the database and the grid refreshing does that.

redpajama_set_name: RedPajamaStackExchange


text:
Archive for the category: Au systems: Archean to the modern Earth
River(ina) of gold – historical activity and structural controls
Au systems: Archean to the modern Earth, ORAL, SESSION 12.1 | ENERGY & RESOURCES
Stuart, Dr Cait1, Ricketts, Mel; Gilmore1, Phil1
1Geological Survey of New South Wales, Department of Regional NSW, Maitland, Australia
The Riverina region of New South Wales is well known for agriculture, but the region also has a long history of gold mining, dating back to the late 19th century. The Riverina has seen relatively little modern mineral exploration. The five-year (2014 to 2019) East Riverina Mapping Project undertaken by the Geological Survey of NSW has highlighted the prospectivity of the region for structurally-controlled, low-sulfide (orogenic) gold, as well as intrusion-related gold and porphyry copper–gold mineralisation.
Structurally-controlled, low-sulfide gold mineralisation within the eastern part of the Riverina region, which extends from West Wyalong to Albury, is hosted by Ordovician to Devonian units and largely located adjacent to the Gilmore Fault Zone. The area has a current endowment (past production and identified resources) of 33.45 t (1.4 M ounces) of gold in 23 identified goldfields situated along the Gilmore Fault Zone and other major, parallel structures.
For each goldfield, a review of historical data, host lithologies, endowment, structural setting, style and timing of mineralisation was undertaken. Each goldfield was considered in a regional structural context. In particular, the structural setting and timing of mineralisation were related to movement along the Gilmore Fault Zone and associated structures.
Structurally-controlled, low-sulfide gold mineralisation was found to occur in three main settings:
In narrow vein arrays in orientations that fit within a Riedel shear model
Veins are typically found in more competent rock types adjacent to second or third order splay faults of the Gilmore Fault Zone or major parallel structures. Mafic dykes are commonly associated with shear zones and may have caused desulfidation of gold-bearing fluids, resulting in mineralisation. Examples of this setting include Adelong, West Wyalong and Sebastopol.
2. Along the contacts between intrusions and metasedimentary country rock, or in pressure shadows of intrusions
Competency contrast between intrusions and metasedimentary rocks is thought to have focussed fluids along these contacts or around competent bodies. Pressure changes during fluid migration likely played a role in gold mineralisation. Examples include Yalgogrin, Weethalle and Grong Grong.
3. Gold found in fold hinges and fold limbs adjacent to the Gilmore Fault Zone
Barmedman is the only recognised example of this style in the area.
Geochronological data for gold mineralisation in the project area are rare and further work is required. However, field relationships indicate the majority of structurally-controlled, low-sulfide gold mineralisation occurred during the Devonian, in the Bindian Event or the Tabberabberan Contraction, with minor mineralisation also potentially occurring during the Ordovician Benambran and Carboniferous Kanimblan contraction events.
Cait Stuart was a Graduate Geoscientist with the Geological Survey of NSW and is now a Geologist with the Northern Territory Geological Survey, where she undertakes mapping and mineral systems projects on NT geology. She has experience in structural and metamorphic geology and has BEnvSc and PhD degrees.v
The Late Archean Au epoch: By-product of Earth degassing
Walshe, John L.1, Bath, Adam, B.1
1CSIRO Mineral Resources, PO Box 1130, Bentley, Western Australia 6102, Australia
It is possible to think of the mineral systems that created the Earth's major mineral deposits and provinces as volato-thermally driven chemical engines with roots deep in the mantle. It may be argued that the chemical potential of systems was linked to this degassing history and reflects the interplay of deep-Earth anhydrous fluids with the Earth's hydrous outer layers. Metal transport and deposition capacity was closely linked to propagation of redox and related physico-chemical gradients through systems. Such arguments imply quite specific links between the formation of the Earth's resources across time and space, secular changes in architecture and geochemistry of the planet over some 4.5 billion years of evolution and Earth phenomena such as mass extinction events, global anoxia and atmospheric evolution. Conceivably a better understanding of large-scale linkages may lead to better techniques for differentiating productive terrains and epochs of Earth history as well as the links between metallogenesis and other Earth processes.
The Late Archean Au deposits, at ~ 2.7 to 2.63 Ga, can be interpreted as one manifestation of planetary degassing of highly reduced and oxidized volatiles. The Late Archaean gold deposits are known from five continents, are hosted within supra-crustal volcano-sedimentary sequences and are spatially associated with trans-crustal structures, 100s of kilometres in length, as exemplified by the deposits of the eastern Yilgarn Craton, Western Australia. All the productive gold camps of the eastern Yilgarn gold province show evidence of deposit to district scale mineral zoning and systematic patterns in 13Ccarbonate and δ34Ssulfide that can be related to chemical gradients sustained by fluxes of reduced (H2, CH4) and oxidized volatiles (SO2) of mantle origin, triggered by tectonic events and related magmatism. Gold transport and deposition was favoured by chemically zoned volato-thermal plumes with an inner core of reduced, alkaline & quartz under-saturated fluids and outer zones of oxidized fluids. Gradients in activity of H2O were sustained by pulsed injection of anhydrous mantle-volatiles into pre-existing crustal hydrothermal systems. Local electrical discharges occurred over distances of ~10 to 100 m, coupled to rock fracturing in the anhydrous parts of systems. Gold deposition was controlled by water activity gradients, coupled with pH and redox gradients.
Sustaining these gradients was key to sustaining gold transport and formation of high-grade resources. Collapse led to dispersion of the gold ± low grade mineralization.
It is hypothesized that the ultimate driver of the Late Archean Au epoch was an electron flux from the core-mantle boundary that released H from the mantle (e + OH_ = O2- + H), drove redox reactions and sustained the volatile flux of the late Archean.
Dr John Walshe is Chief Research Scientist, CSIRO Mineral Resources. Since joining CSIRO in 1995, Dr Walshe has contributed to developing mineral systems concepts and applications to mineral exploration. Prior to joining CSIRO, Dr Walshe lectured at the Australian National University. He is a graduate of the University of Tasmania.
Apatite chemistry indicates that oxidized auriferous fluids along the world-class Boulder Lefroy – Golden Mile fault system were significantly different to fluids from global porphyry systems
Bath, Dr Adam, B.1, Walshe, John, L., Ireland, Tim., Cobeñas, Gisela., Sykora, Stephanie., Cernuschi Federico., Woodall, Katie., MacRae, Colin., Williams, Morgan., Schmitt, Leanne.
1CSIRO Mineral Resources, PO Box 1130, Bentley, Western Australia 6102, Australia, 2First Quantum Minerals Ltd, 1/24 Outram St, West Perth WA 6005, 3Lundin Mining, El Bosque Norte 500, piso 11, Of. 1102, Las Condes, CP 7550092, Santiago, Chile
The Boulder Lefroy – Golden Mile (BL-GM) fault system contains >70 Moz of gold and accounts for more than a quarter of the known gold mineralization in the Archean Yilgarn Craton, Western Australia. Alteration along the BL-GM fault system shows a wide range of redox conditions (hematite/anhydrite- to pyrrhotite-stable), and this range in many cases can be linked to mineralization. Oxidized fluids have been linked to adakitic magmas or more generally, Au fluids linked with sub-arc mantle wedges. However, invariably in Archean Au systems there is a lack of evidence of causative intrusions at the time of oxidized alteration and mineralization, leading numerous authors to reject the possibility that magmas were a major source of auriferous fluids. Despite this, oxidized fluids derived from deeper concealed intrusions cannot be ruled out, particularly given the length and breadth of anhydrite alteration can be spatially significantly large (km-scale). Here we present mineral and isotopic datasets on oxidized fluids from the BL-GM fault system with the aim to view these datasets in comparison to those from porphyry systems. Porphyry Cu-Au systems are associated with oxidized magmatic fluids generated in arc environments, and here we test if apatite chemistry can be used to make any links between oxidized fluids in Archean Au systems and global porphyry systems. Close to 1000 apatite analyses were obtained on the electron microprobe. The apatite crystal formula is Ca5(PO4)3X, where X represents the channel volatile site that runs parallel to the crystallographic c-axis, occupied by OH, F, and Cl. Results from our dataset show that apatite from gold-bearing oxidized alteration assemblages in Archean Au system have variable amounts of F (2.5 to 4.1 wt. %), whereas Cl values remain low (<500ppm) over the wide range of F values. In contrast, apatite from porphyry Cu-Au deposits with anhydrite have a wide range of F values (2.2 to 4.8 wt. %) and show a significant linear increase in Cl (<300ppm to 1.7 wt. %) with decreasing F. The stark difference in the X-site substitution appears the main variance between the chemistry of apatite from the two environments. In hydrothermal Archean Au and porphyry Cu-Au systems, higher amounts of F tend to correspond to lower temperatures (based on biotite-apatite thermometer). Also, previous experimental studies show that relatively low Cl and F concentrations in acidic (H20-HCI) fluids result in high ratios of XClAp/XOHAp and XFAp/XOHAp in apatite, whereas much higher abundances of CI and F are required in basic fluids to achieve the same result. Data from previous studies also show that the dilution of aH2O with higher aCO2 results in apatites with higher ratios of XCIAp/XOHAp and XFAp/XOHAp from fluids with comparatively lower levels of Cl or F. Our data shows no evidence of these processes. The most plausible explanation for the comparatively low XCIAp/XOHAp apatites from Archean Au systems is that the fluids were comparatively low saline compared to those from oxidized alteration assemblages in porphyry Cu-Au systems. Furthermore, results of this study show that apatite from oxidized and reduced alteration assemblages of Archean Au systems across the Yilgarn Craton plot along the same trend on the Cl versus F diagram. One notable difference between the two populations is that those forming part of reduced alteration assemblages have lower F values (1 to 3.3 wt. %) and appear to be associated with hotter fluids.
Mineral system scientist with experience of mapping, characterising and exploring for Cu and Au mineral systems in a range of terranes. Experience developing and implementing new and novel techniques towards mapping hypogene alteration and exploring in Archean gold systems in various terranes of the Yilgarn Craton at the camp-scale.
Source of gold in Neoarchean orogenic-type deposits in the North Atlantic Craton, Greenland: Insights for a proto-source of gold in sub-seafloor hydrothermal arsenopyrite in the Mesoarchean
Saintilan, Dr Nicholas J.1,7*, Selby, D.1,2, Hughes, J. W.1,3, Schlatter, D. M.4, Kolb, J.5, Boyce, A.6
1Department of Earth Sciences, University of Durham, Durham DH1 3LE, United Kingdom, 2State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Resources, China University of Geosciences, Wuhan, China. 3Bluejay Mining Plc, 2nd Floor, 7-9 Swallow Street, London, W1B 4DE, United Kingdom, 4Helvetica Exploration Services GmbH, Carl-Spitteler-Strasse 100, 8053 Zürich, Switzerland, 5Institute of Applied Geosciences, Department of Geochemistry and Economic Geology, Karlsruhe Institute of Technology, Adenauerring 20b, 76131 Karlsruhe, Germany, 6Isotope Geoscience Unit, SUERC, Rankine Avenue, East Kilbride, Glasgow G75 0QF, United Kingdom, 7Present address: Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zürich, Clausiusstraße 25, 8092 Zürich, Switzerland
Given that gold (Au) mostly remained in the incipient Earth mantle until ca. 3.9–3.8 Ga, a "proto-source" of gold may have been present in the dominantly mafic crust precursor born through first-stage melting of the early Earth mantle. In south-westernmost Greenland, a fragment of the North Atlantic Craton is characterised by greenstone belts comprising mafic volcanic and magmatic rocks, and harzburgite cumulates that were emplaced at ca. <3.19–3.01 Ga (e.g., Tartoq greenstone belt). Here, combining detailed sulphide petrography with rhenium-osmium-sulphur (Re-Os-S) isotope geochemistry of individual mineral separates of arsenopyrite from gold-sulphide mineralised shear zones, we pinpoint the precipitation of ca. 3.18–3.13 Ga (Re-Os model ages) hydrothermal arsenopyrite associated and coeval with arc-related magmatism of the Tartoq Group. We consider sub-seafloor hydrothermal alteration of the oceanic crust and magmatic activity to have supplied arsenic (As), Re, and Au, to result in the precipitation of the ca. 3.18–3.13 Ga arsenopyrite with primary invisible gold. Additionally, in major shear zones in a rigid juvenile continental crust, retrograde greenschist-facies metamorphism overprinted the ca. >3.0 Ga prograde amphibolite-facies metamorphic assemblages and caused local dissolution of arsenopyrite. During this retrograde tectono-metamorphic stage, in gold-rich shear zones, the Re-Os geochronometer in arsenopyrite was reset to a Neoarchean age while invisible gold was liberated and deposited as free gold with 2.66 Ga pyrite (Re-Os isochron ages). The initial Os isotope ratios of Neoarchean arsenopyrite (187Os/188Osi = 0.13 ± 0.02) and gold-bearing pyrite (0.12 ± 0.02) overlap with the estimated 187Os/188Os ratio of the Mesoarchean mantle (0.11 ± 0.01) and preclude contribution of radiogenic crustal Os from evolved lithologies in the accretionary arc complex, but instead, favour a local contribution in Os from basaltic rocks and serpentinised harzburgite protoliths by metamorphic fluids. Thus, the ca. 2.66 Ga lode gold mineralisation identified in the North Atlantic Craton may illustrate a gold endowment in shear zones in Earth's stabilizing continental crust at the time of the 2.75–2.55 Ga Global Gold Event, through metamorphic upgrading of bulk gold which had originally been extracted from the Mesoarchean mantle and concentrated in hydrothermal arsenopyrite deposits in oceanic crust beneath the overall reduced Mesoarchean ocean.
‡Saintilan et al. (2020) Source of gold in Neoarchean orogenic-type deposits in the North Atlantic Craton, Greenland: Insights for a proto-source of gold in sub-seafloor hydrothermal arsenopyrite in the Mesoarchean. Precambrian Research 343, 105717.
Nicolas Saintilan has set up and manages a Re-Os geochronology laboratory at ETH Zürich in Switzerland. He is an Ambizione Fellow of the Swiss SNF and holds a PhD from the University of Geneva with postdocs with Rob Creaser and Dave Selby in Canada and the UK successively.
Do rocks deposited during time periods with high gold in sedimentary pyrite host more gold mineralization?
Gregory, Daniel1, Lui, Timothy1, Wu, Selina1, Large, Ross2
1University of Toronto, Toronto, Canada, 2ARC Centre of Excellence in Ore Deposits (CODES), School of Physical Sciences, University of Tasmania, Hobart, Australia.
Over the past 10 years it has become increasingly common for people to view host rocks, often sedimentary rocks, to be a source of metals for orogenic gold systems. For sediment hosted deposits it has been proposed that syngenetic and/or diagenetic pyrite may be an important source of the gold. This model states that the gold is released during metamorphism, after which it migrates with metamorphic fluids and is deposited in trap sites. During the same time period it was shown that pyrite trace element content, including gold, varies significantly through geologic time. Thus, it stands to reason that an initial step to finding new gold districts may be to identify basins / periods of time when gold is elevated in sedimentary pyrite. Databases of trace element content of sedimentary pyrite show that gold was elevated at approximately: 3 Ga, 2.5-2.7 Ga, 1.9 Ga, 0.9 Ga, 550 Ma, 450 Ma, and 300 Ma (Precambrian ages +/- 100 Ma; Phanerozoic +/-50 Ma to encompass the length of time that sedimentary pyrite is generally elevated in gold). These are also the ages of the host rocks for many important gold districts (for example, the Superior and Yilgarn craton orogenic gold deposits, the Witwatersrand deposits, the Sukoi Log deposit, the Bendigo district, and the Carlin district). In this study we went to an area where gold deposits occur but is not one of these more famous districts where gold is well established to be hosted by sediments the same age as those with elevated gold in pyrite: Queensland Australia. Approximately 8658 known gold deposits or occurrences are present in Queensland. Of these 3023 (35%) are host by the stratigraphy of the ages given above, a further 898 (10%) are within 1 km and 1579 (18%) are within 5 km. Furthermore, the geologic units of prospective age encompass less than 5% of the land area of Queensland. This suggests that indeed gold deposits are more likely to form in areas that are likely to have elevated gold in sedimentary pyrite and these stratigraphic packages should be prioritized when searching for new gold districts.
Daniel Gregory is an Assistant Professor at the University of Toronto. He completed his PhD focussing on pyrite chemistry at CODES, University of Tasmania in 2014 before spending 3 years as a post doc at the NASA Astrobiological Institute at the University of California Riverside.
Lifting the cloak of invisibility: Gold in pyrite from the Olympic Dam deposit, South Australia
Ehrig, Kathy1,2, Ciobanu, Cristiana3, Verdugo-Ihl, Max3, Dmitrijeva, Marija3, Cook, Nigel2, Slattery, Ashley4
1BHP Olympic Dam, Adelaide, Australia, 2School of Civil, Environmental and Mining Engineering, University of Adelaide, Adelaide, Australia, 3School of Chemical Engineering and Advanced Materials, University of Adelaide, Adelaide, Australia, 4Adelaide Microscopy, University of Adelaide, Adelaide, Australia
'Invisible gold' in pyrite refers to gold either present within the sulfide lattice or as discrete nanoparticle (<100 nm-diameter) inclusions (NPs), making it undetectable by conventional optical and scanning electron microscopy. Investigation of "invisible gold" in chalcopyrite-pyrite ores from the Olympic Dam Cu-U-Au-Ag deposit (one of the world's largest Au deposits) confirms the presence of Au in some arsenic-bearing pyrites at concentrations measurable by laser ablation inductively coupled-plasma mass spectrometry (LA-ICP-MS). Arsenic-bearing pyrite in the studied sample shows As-Co-Ni-oscillatory zoning patterns with variable complexity suggesting grain re-crystallization during replacement by chalcopyrite. LA-ICP-MS data obtained from 164 pyrite grains plot below the Au and As solubility limit empirically defined from studies of epithermal and Carlin-type deposits.
Several As-rich pyrite grains were analyzed using Scanning Transmission Electron Microscopy (STEM) and EDX-STEM analysis of foils obtained by Focused Ion Beam methods. Micron-scale, oscillatory zoning patterns observed on back-scattered electron (BSE) images and LA-ICP-MS element maps extend down to the nanoscale. Decoupling between trace elements is common, for example Ni depletion wherever As and Co are enhanced, with nucleation of discrete Co-As-bearing NPs (cobaltite/safflorite?)
Importantly, Au-bearing NPs are identified in all cases, in intimate association with other (sulpho)tellurides. In addition, abundant cassiterite and rare chalcopyrite NPs are also identified. Some of the largest Bi-Ag-telluride NPs contain electrum as tiny pore-attached NPs within the larger telluride. Nanometer-size electrum NPs were also identified in association with chalcopyrite. Silver-Au-telluride NPs form mono- or bi-component NPs. These NPs occur along trails displaying As-Co-enrichment, or formation of nm-wide lamellae of Bi-Pb-sulphotellurides marking pyrite twin boundaries. One wider lamella was identified from the layer stacking as a strongly disordered member of the aleksite series. Coarser tellurobismuthite (Bi2Te3), a few μm-wide, is associated with altaite (PbTe) at pyrite-chalcopyrite boundaries.
Pyrite displays kink- and screw-dislocations associated with trace element remobilization or NPs nucleation. These defects can be associated with either 'marcasitization' or loss of Fe (formation of pyrrhotite), within nanoscale domains affected by fluid percolation and pyrite recrystallisation. Twin planes in pyrite enriched in heavy elements (Bi-Pb-Te) represent zones of weakness and assist element exchange between host mineral and percolating fluids during coupled dissolution reprecipitation reactions (CDRR), analogous to those known for hematite from Olympic Dam.
Nanoscale textures in pyrite allow for interpretation of Au-NPs as Au released from solid solution in pyrite during CDRR associated with marginal chalcopyrite replacement. Nanoscale analysis lifts the cloak of invisibility for Au in pyrite at Olympic Dam. These results show that confirmation of whether gold occurs as NPs or in solid solution based solely on position above or below the solubility limit of Au in pyrite on a plot of Au vs. As is impossible without corroborative studies at the nanoscale.
Kathy completed a PhD from the University of California- Berkeley in 1991 and left San Francisco in 1992 to join the former WMC as a research geologist to work on the genesis of the Olympic Dam deposit. She currently leads the team who built the geometallurgical model of Olympic Dam.
Stability of gold nanoparticles in sulfur-bearing hydrothermal fluids: an experimental study
Liu, Weihua1, Chen, Miao1, Yang, Yi1, Mei, Yuan1, Etschmann, Barbara1, Brugger Joël1, Johannessen, Bernt 1
1CSIRO Mineral Resources, Clayton,, Australia, 2Monash University, Clayton,, Australia, 3Australian Synchrotron, Clayton,, Australia
Current theories of the gold deposit formation from hydrothermal fluids have been challenged by recent field and laboratory observations, suggesting that gold nanoparticles/colloids could be important in gold transport/deposition in ore fluids. In this study, the stability of gold nanoparticles (colloidal gold) in sulfur-bearing and citrate-bearing solutions was investigated at temperatures up to 225˚C using Synchrotron X-ray Near-edge Spectroscopy (XANES), and up to 350˚C with a visual check of colour change. The citrate-based colloidal gold solutions, with or without colloidal silica in the solution, are only stable up to 225˚C. In contrast, the gold colloids in Na2S solutions are not stable upon heating to 150˚C, but stable up to 300˚C when 0.5-1.5 wt% of colloidal silica is present in the solution. The colloidal gold particles started to aggregate and deposit from the solution with the aggregation and growth of silica particles at 350 ˚C. The concentrations of gold as colloids in the solutions are up to 0.5 mmol (~95 ppm), more than three orders of magnitude higher than gold solubility as aqueous complexes under the same condition calculated based on available thermodynamic data. These results provide the first evidence that high concentrations of gold nanoparticles are stable in sulfur-bearing fluids at elevated temperatures (~300˚C). This implies that the formation of gold nanoparticles is an effective way to concentrate gold in hydrothermal sulfur-bearing fluids to form high-grade gold ores.
Dr. Weihua Liu is a senior research scientist at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and was an Australian Research Council Future Fellow
Weihua's research has been focused on the investigation of metal mobility and mineral/fluid reactions in hydrothermal systems, combining both experimental and theoretical techniques.
The unusual Imou porphyry Au-Cu deposit, Western Highlands PNG
Ireland, Timothy1; Federico Cernuschi2, Robert Sievwright1, Hannah Goswell1, Stefanova, Elitsa3, and John Dobe4.
1First Quantum Minerals Ltd, Canada, 2Eclectic Rock Ltd, Punta del Este, Uruguay, 3Bulgarian Academy of Science – Geological Institute, Bulgaria, 4Footprint Resources Pty Ltd
Imou (4.944˚S; 142.806˚E) is a porphyry gold-copper deposit located western Papua New Guinea along structural strike between the deposits at Frieda River and Yandera. The area was highlighted during systematic geochemical exploration in the mid-1970s, when five porphyry centres were identified in a camp covering ~30 x 30 km. The Imou target was delineated in the 1990s as a stream sediment and soil Cu anomaly of >500 ppm coincident with Au anomalism >0.2 ppm and associated with a magnetic polyphase porphyritic intrusive complex. Two holes drilled in 1999 discovered the deposit, and a dozen recent holes permit this first attempt at geological description.
Magmatic rocks comprise equigranular and lesser porphyritic diorites that belong to the Nekiei intrusive suite, which was emplaced into a thrust duplex of obducted siltstone and oceanic crust. New zircon-U-Pb geochronology records at least 700 ky. but less than 2.1 my. of Late Miocene magmatic evolution. The intrusions are low to mid-K calc-alkaline series rocks composed primarily of calcic plagioclase and hornblende with rare biotite and quartz, and accessory titanomagnetite. Whole rock chemical proxies for porphyry fertility are comparable to causative suites in other deposits (Sr/Y up to 65 and V/Sc up to 16) but zircon in these rocks has relatively low concentrations of U, Th, LREE and Hf .The intrusions manifest in airborne magnetic surveys as discrete high amplitude magnetic 'bullseye' features, but no cogenetic large plutons are observed at surface, nor can be inferred from the magnetic response.
The outcropping manifestation of the porphyry deposit at Imou is in many ways typical: within a geochemical footprint of ~2 km2 there are domains of A-family quartz veins that sometimes contain Cu-Fe-sulphides and/or magnetite, the distribution of which broadly coincides with the occurrence of hydrothermal magnetite, feldspar, anhydrite and muscovite. These quartz vein domains reach 50 vol% quartz in the vicinity of the magnetite-bearing assemblage. There are structurally controlled domains of late D-veins and phyllic alteration, followed by post-mineral porphyritic dykes. However, there are numerous differences with economic PCD described elsewhere. Cu-Au grade is not associated with the abundance of A-family quartz veins. Further, there is no petrographic nor bulk chemical evidence for large volumes of potassic alteration. Observed feldspars are albite and sporadic hydrothermal biotite represents only remobilisation of local potassium. There is little disseminated sulphide associated with this alteration, instead, grade development is associated with chalcopyrite-pyrite-(magnetite) fracture paints, and sulphide-anhydrite veins that cross-cut the quartz vein stages. These paragenetically late brittle veins are widely distributed at low frequency, but are associated with best Cu-Au grades. These late hydrothermal features are not systematically associated with a particular wallrock alteration assemblage, although chlorite-montmorillonite is the dominant alteration assemblage outboard of localised sericite- and albite-bearing assemblages.
We advance several working hypotheses for why Imou differs from other porphyries, and especially why metals did not precipitate efficiently with the early high temperature alteration and quartz veining. We speculate that many barren or subeconomic porphyries may have inferior Cu-Au grade development for similar reasons.
I'm a jack-of-all-trades explorer with experience in porphyry-epithermal systems, carlin-type deposits, sed-hosted Cu and sed-hosted Zn. I'm currently the Principal Exploration Geologist – and informal resident geochemist – at FQM. I did my postgrad research at CODES, and have spent much of my career working in E Europe and the central African copperbelt.
Evolution of magmatic fertility for porphyry Au & Cu deposits through the prism of zircon chrono-chemistry, Balkan Peninsula, SE Europe
Ireland, Timothy1; Bilyarska Teodora2, Bilyarski, Stoimen1, Protic, Nenad1, and Stefanova, Elitsa3
1First Quantum Minerals Ltd,, Vancouver, Canada, 2St Kliment Ohridski University of Sofia, Sofia, Bulgaria, 3Bulgarian Academy of Science – Geological Institute, Sofia, Bulgaria
The accreted arc terranes of the Balkan western Tethyan host a complex metallogeny that includes almost all Cu and Au mineralisation styles typical of subduction-related arcs and post-collisional settings. Broadly, magmatism in the belt began as a series of submarine arcs constructed on thinned continental basement, and evolved to subaerial post-collisional magmatism during and after arc-continent collisions in the Late Cretaceous and Eocene. Each collisional event is associated with a phase of metallogenesis that changes in terms of metal budget and deposit style as collision occurs and then collapses, e.g. in the Timok and Panagjurishte districts, three phases of magmatism, each lasting 5-10 my. record a transition in space and time from sub-volcanic diorites associated with porphyry Cu-Au deposits, to more voluminous effusive andesites associated with epithermal deposit styles, and then monzonitic intrusions with a Au-dominant metal budget. The rocks from all of these three phases are the products of hydrous, intermediate magmas that yield equivalent 'fertile-looking' results in terms of whole rock magma chemistry proxies such as Sr/Y that explorers may use for area selection in arc environments.
A similar metallogenic progression occurs among less well-documented magmatism that occurred subsequent to the Alpine orogeny. In this case the main, early metallogenic phase is represented by porphyry and epithermal Cu-Au deposits associated with trachyandesite and monzonitic volcano-plutonic complexes. As post-collisional extension comes to dominate the regional tectonic environment the metallogeny becomes dominated by Pb-Zn in a series of 'ore fields' that we infer to be genetically related to syn-extensional granitoids, and thereafter by epithermal gold deposits in terrestrial grabens.
In this study we compiled all the available published whole rock chemistry and zircon chronology and chemistry for magmatic rock units associated with each of these metallogenic stages, and collected new complementary data from rock samples and stream sediments. The result is a coherent record of the temporal evolution of magmas associated with each of these metallogenic stages. We observe that the detrital zircon populations are closely related to the results from rock samples, however, we contend that the detrital record is a superior medium as it avoids sampling bias and undersampling. These detrital results were interpreted as a holisitic record of the magmatism in each district. There are patterns among this zircon chrono-chemical evolution that correspond to consistent aspects of regional metallogeny. Short periods of zircon crystallisation (i.e. <3 my) in which zircons span a wide range of compositions suggesting both primitive and enriched or evolved source contributions tend to characterise the metallogenic events in which Au is the primary economic commodity. In contrast, more protracted zircon crystallisation history and slower evolution to fertility implied by proxies such as Eu/Eu* characterises the major porphyry Cu camps. This approach may be applicable in other terranes wherein the magmatic-metallogenic history is not well constrained.
Controls on gold endowments of porphyry deposits
Au systems: Archean to the modern Earth, KEYNOTE, SESSION 11.1 | ENERGY & RESOURCES
Massimo, Chiaradia1
1Department of Earth Sciences, University of Geneva, Geneva, Switzerland
Porphyry deposits are natural suppliers of ~75% copper and ~20% gold to our society. Nonetheless, gold endowments of porphyry deposits are characterized by a wide range going from a few tons to >2500 tons of gold. Here, I propose a model to explain the reasons of the large variations in metal endowments of porphyry Cu-Au deposits.
Porphyry Cu-Au deposits define two distinct trends in Au versus Cu tonnage plots: Cu-rich (Au/Cu ~4*10-6) or Au-rich (Au/Cu ~80*10-6). Cu-rich porphyry deposits are related to Andean-type subduction and typical calc-alkaline magmatism in thick continental arcs. In contrast, Au-rich porphyry deposits are associated with high-K calc-alkaline to alkaline magmatism in late to post-subduction or post-collision and extensional settings, and also with calc-alkaline magmatism. The largest Au-rich porphyry deposits are associated with high-K calc-alkaline to alkaline magmatism. Geochronological data at individual porphyry deposits suggest that gold endowments for both trends grow larger the longer the mineralization process is. However, Au is precipitated at much higher rates in Au-rich (~4500 tons Au/Ma) than in Cu-rich porphyry deposits (~100 tons Au/Ma).
Monte Carlo modelling of petrologic processes suggests that the different rates of gold precipitation in Cu-rich and Au-rich porphyry deposits most likely result from a 5-12 times better efficiency of gold precipitation in Au-rich than in Cu-rich deposits. The reason of the different efficiencies of gold precipitation is the different depths of formation of Cu-rich and Au-rich porphyry deposits which favour (deep level) or not (shallow level) a decoupling of Au and Cu precipitated from the magmatic-hydrothermal fluids. Interestingly, Au-rich porphyry deposits formed at shallower levels are also associated with magmatic rocks that have evolved at average shallower levels than Cu-rich deposits, as suggested by systematically lower Sr/Y values of the former (Au-rich systems) with respect to the latter (Cu-rich systems). Monte Carlo modelling shows that the higher gold endowments of Au-rich porphyry deposits associated with alkaline magmas require higher gold contents in the parental magmas such as those that are typical of alkaline magmas but not of calc-alkaline ones. This suggests an additional petrogenetic control in the formation of the Au-richest porphyry deposits associated with variably alkaline magmas.
Whereas depth of porphyry formation and chemistry of magmas (alkaline versus typical calc-alkaline) seem to control the Au-rich versus Cu-rich nature of porphyry Cu-Au deposits, the correlation of the Cu and Au endowments with ore deposition duration suggests that the final Cu and Au endowments of these deposits are determined by the cumulative number of mineralizing steps that are ultimately controlled by magma volume and ore process duration. The difference is that variably alkaline systems and shallow crustal calc-alkaline systems are inherently associated with magmas, whose fluids are tectonically (i.e., shallow emplacement) and chemically (alkaline magmas) optimized for high gold precipitation efficiency. In contrast, typical calc-alkaline (high Sr/Y) magmas form in a geodynamic context that favours enormous magma accumulations, which are necessary to produce behemothian Cu-rich deposits, but are emplaced at depths at which the exsolved fluids are less efficient for gold precipitation.
Biography to come.