AMT Geophysics Survey

Chesterfield Resources / EPIC: CHF / Market: LSE / Sector: Mining

1 September 2020

Chesterfield Resources Plc

AMT Geophysics Survey

Chesterfield Resources plc is pleased to announce that it has commissioned an AMT (Audio-magnetotellurics) geophysics survey for its Troodos West licence area in Cyprus. This will assist the company in its exploration for copper and gold mineralisation. AMT is an advanced technology that measures the natural electromagnetic signals in the earth's crust, which is generated by lightning strikes, to create a high resolution image of geological features underground.

The company will shortly be commencing a new campaign of percussion and diamond drilling at the site. The survey will be run towards the start of this programme, as part of an integrated work-stream, to help direct the drilling. The survey is relatively quick to conduct, and its results can be processed and analysed within a few days of each survey segment.

The AMT survey data is then layered over other types of target evidence, such as geological mapping, soil surveys and historic drilling, to provide a clearer picture of each target area. Typically, these enhanced targets will be tested with a percussion drill, and if sufficient sulphide mineralisation is located, then tested with a diamond drill.

The company's technical team determined that AMT was likely the most accurate and cost-effective survey to identify massive sulphide targets in our project. The technology has been well-proven as a target defintition tool in similar VMS (Volcanogenic Massive Sulphide) belts including the Iberian Pyrite Belt.

Martin French, Executive Chairman said "We have designed a co-ordinated campaign to test a number of our targets with three tools: AMT geophysics, percussion and diamond drilling. This season's programme needs to be completed before the weather gap closes around November. We believe this integrated programme is a much more effective way to test our targets than simply a stand-alone diamond-drill campaign. AMT is a very interesting technology that analyses the natural electrical charges in the earth. The timing of the survey allows us to use some of our recently-discovered underground sulphide deposits to help verify and calibrate its measurements. September is going to be a busy month."

What is an AMT survey?  

Different types of rocks underground conduct electricity at different rates according to their composition. Geologists use geophysics to take of number of readings from the surface (usually in a grid or a line) of electrical resistance which collectively build a picture of geological structures underground, and so help identify the likely position of mineral deposits.

There are different techniques to do this. Previously, Chesterfield conducted an IP (Induced Polarisation) survey which involved placing probes in the ground which were then charged with an electrical current. This "induced" a charge in the rocks beneath which was then measured by sensors from different locations. This IP survey helped locate the mineralisation discovered at our Evlin target.

An AMT survey works the other way around by measuring variations in electrical charges that already exist naturally in the earth's crust. It is a branch of geophysics called magnetotellurics (MT), using what are often referred to as "natural source" surveys.

Audio-magnetotellurics (AMT) is particularly suited to shallower mineral surveys. It is a type of MT survey that measures natural high frequency signals in the audio range (i.e. >1 Hz). These are signals that are generated by lightning strikes that continually hit the earth around the globe. These induce time-varying electric and magnetic fields into the earth's crust and oceans. These currents produce signals which can then be measured over a range of frequencies using probes and magnetic field antennas. Ground resistivity values are then calculated from these AMT measurements, creating a 3D image of the subsurface.

It usually takes just one or two hours to perform each measurement and involves relatively light man-portable sensors. The method is capable of imaging the sub-surface with resolutions good enough to detect features a few meters across.

This is particularly suited to Chesterfield's exploration project in Cyprus. Crucially, the company believes the survey will be able to differentiate between sulphide mineralisation and sedimentary rocks (which can prove difficult with other types of electromagnetic survey) and also provide a useful indication of the depth at which mineralised deposits may occur.

Follow us on Twitter at @ChesterfieldPlc 

About Chesterfield Resources Plc

Chesterfield Resources is a copper-gold exploration and development Company active in Cyprus. The Company strategy is to generate value for shareholders by discovering and developing multiple deposits to production. Chesterfield is in the advanced stage exploration in on its Troodos West licence area, and has a large bank of licence areas elsewhere in Cyprus, either granted or under application.

Market Abuse Regulation (MAR) Disclosure

Certain information contained in this announcement would have been deemed inside information for the purposes of Article 7 of Regulation (EU) No 596/2014 until the release of this announcement.

**ENDS**

 For further information, please visit www.chesterfieldresourcesplc.com or contact: