The inimitable Bamps posted some very useful posts over the Jubilee Weekend on how the GGP MRE was structured and about other considerations in the estimation of the resource/reserves playing an important part other than drilling density. I decided to try and delve into things a bit more to help me understand how the GGP MRE was structured and while being far less conservative than the very conservative Newcrest PFS is still JORC compliant.
I was also curious in the methodology/maths used to enable an estimate on the Eastern Breccia with so little data but some very long and stable intersections and help build on my very (!) basic understanding of how these enable predictions to be made with more confidence vs a more varied type of mineralisation style in other sections of the ore body.
Learning about topics such as Kriging and the use of 'Unfolding' has really helped me gain a far better understanding of how drill data can be utilised by geo's along with certain techniques to build these estimates. Also focusing on the GGP MRE in minute detail and reading through it thoroughly, I noted how often it referred back to the Newcrest PFS and justified it's own conclusions and methodology in ore estimation vs the PFS and realised how it was aimed at assisting in the 5% Option Exercise negotiations, page 8 of the GGP MRE summarises the material differences between the two.
Links below to useful information that might help understand Bamp’s posts (Page 2 onwards in the link at the bottom of this post) on the techniques that helped the GGP team form their MRE:
• GGP Independent Resource & Reserve Update:
- https://greatlandgold.com/wp-content/up ... images.pdf
• 15 min video that covers Kriging ‘The Kriging Model : Data Science Concepts’:
- https://www.youtube.com/watch?v=J-IB4_QL7Oc
• Information on application of unfolding in ore body estimation:
- https://www.researchgate.net/publicatio ... evaluation
• Link to YouTube channel and website for mining software utilised by GGP:
- https://www.micromine.com/
- https://www.youtube.com/c/Micromine
"Geostatistics" is the generic name for a family of techniques which are used for mapping of surfaces from limited sample data and the estimation of values at unsampled locations. Kriging was first developed almost 60 years ago by Georges Matheron and named in honour of Danie Krige, these methods are now widely used in the minerals industry and have disseminated out into many other fields where 'spatial' data is studied.
Geostatistical estimation is a two-stage process:
I. Studying the gathered data to establish the predictability of values from place to place in the study area; this study results in a graph known as a semi-variogram which models the difference between a value at one location and the value at another location according to the distance and direction between them;
II. Estimating values at those locations which have not been sampled. This process is known as 'kriging'. The basic technique "ordinary kriging" uses a weighted average of neighbouring samples to estimate the 'unknown' value at a given location. Weights are optimized using the semi-variogram model, the location of the samples and all the relevant inter-relationships between known and unknown values. The technique also provides a "standard error" which may be used to quantify confidence levels.
In mining, Geostatistics is extensively used in the field of mineral resource and reserve valuation - the estimation of grades and other parameters from a relatively small set of borehole or other samples. Geostatistics is now widely used in many other fields. Obviously, there are geological and geographical applications.
However, the techniques are also used in such diverse fields as hydrology, ground water and air pollution, soil science and agriculture, forestry, epidemiology, management of wildlife and weather prediction.
(ref: http://www.kriging.com/whatiskriging.html)
LINK TO DOWNLOAD FILE CONTAINING SCREENSHOTS OF BAMPS THOUGHTS:
https://www.mediafire.com/file/flngyoov ... e.pdf/file
Links to assist with understanding MRE's:
- https://www.ggpchat.co.uk/viewtopic.php?t=670
- https://www.ggpchat.co.uk/viewtopic.php?t=718
The GGP MRE, Kriging, Unfolding and some Bampology!
The GGP MRE, Kriging, Unfolding and some Bampology!
Last edited by DipSard on Fri Sep 22, 2023 4:04 pm, edited 2 times in total.
“Study the past if you would define the future.” ― Confucius
Re: The GGP MRE, Kriging, Unfolding and some Bampology!
Thanks Dip, v informative.
I do note again the section in the GGP R& R statement which clearly sets out the potential for growth at that time, ie they were setting out their stall in terms of the potential value of the Hav system, in advance of the 5% negoatiations to come. They really have been v professional in their approach to this project in recent times.
I do note again the section in the GGP R& R statement which clearly sets out the potential for growth at that time, ie they were setting out their stall in terms of the potential value of the Hav system, in advance of the 5% negoatiations to come. They really have been v professional in their approach to this project in recent times.