Abstract
This article presents my basic workflow for finding, exploring and recording new localities. It touches on a number of novel, arguably groundbreaking, technologies that greatly enhance the capabilities of the average mineral collector such as personal drones and free satellite imagery.
Introduction
Nostalgia is probably a widespread feeling amongst mineral collectors who might occasionally find themselves pining for the past and the golden eras when their favourite mines and mineral localities were being worked. One cannot help but imagine what great treasures were unearthed and likely overlooked in past decades and centuries. This is most certainly true of my home country of Ireland where mineral collecting is, sadly, a comparatively new phenomenon. Mineral collecting has certainly taken place in the past but it was sporadic and often localised leaving many important discoveries at the mercy of mother nature or the jaws of a crusher. This mentality can leave the modern collector feeling jaded and demoralised. With so many localities becoming lost, forgotten and even obliterated, it feels like making significant new finds is a thing of a bygone era. Thankfully, with the help of modern technology, this could not be further from the truth!
Today's typical mineral collector now has more capability to prospect and explore mineral localities than at any point in human history. In fact, with advances in modern technology they now have access to free satellite imagery and other large remote sensing datasets which were once only available to large, deep pocketed exploration companies. With the proliferation of cheap, high-tech commercial drones, today's collector even has the capability to make their own high resolution maps of unexplored regions and make new finds. One cannot understate the immense benefit of an aerial viewpoint. It enables quick, easy surveying of terrain that, on foot, may be nothing more than impenetrable vegetation. Similarly, one can rapidly assess dangerous terrain like cliffs, mountains and quarries from the safety and comfort of their vehicle.
The Workflow
1. Research - "Fail to prepare, prepare to fail"
The first step in finding localities or lost mines is always research. No matter where you are in the world there is a good chance that information already exists from those who have come before you. These could be old exploration reports, abandonment plans or historical maps and are likely available, often freely, from your national geological survey organisation or mapping agency.
The following example is a real case study for a mine that I have never visited and it was unclear if it still even exists today. Historic records report a Victorian era copper mine in the vicinity of Twigspark, Manorhamilton, Co. Leitrim, Ireland likely worked around 1845. Naturally, modern maps show no record of this mine as it has probably been long since obliterated.
2. Historic Maps
The next step is to review historic maps such as the old 6" to a mile Ordnance Survey map and search in the general region of Twigspark. Sure enough we can see something marked "Silver mine" on the map and a number of roads and paths that have clearly changed in recent years.
3. Aerial Photographs
The next step is to check modern aerial photographs (if available) to see what sort of terrain the mine is situated in and what the current state is. The below photograph shows that the minesite is now a cultivated green field which is not encouraging and often suggests that the mine has been cleared and is now obliterated. This aerial photograph is relatively old and dates from 2005 so the site may have changed further in recent years. Though the site is a green field, there are still traces of the old mine track and, more importantly, we can see some sort of ground disturbance in the left of the photo (circled in red). This could be a mound of earth from field clearance or perhaps it could be an open-pit. Higher resolution imagery is required...
4. Satellite Imagery
Free online satellite imagery services such as Google maps, Bing maps and Apple maps offer incredible resolution aerial imagery of many countries. The clever collector will be tool agnostic and cross reference and use all services available to them. For this particular region in Ireland, Bing maps offers the highest resolution and most recent imagery.
The Bing satellite imagery offers a dramatic improvement in detail. One can now clearly make out the old mine path and the feature of interest in the aerial photo is now clearly some sort of flooded pit with a trench leading out of it. There also appears to be potential spoil heaps surrounding pit. To the right of the photograph we can see a farm building at the end of the track which gives a strong indication of where the landowner may live. This is invaluable as now it clear where to seek permission and, more importantly, local knowledge on the location of the mine. Landowners should always be consulted for permission to access their land and a great added benefit of this is that they can often give a historical account of how the land has changed over time.
5. GoogleStreetview
Without leaving the comfort of our desk, we have gone from an old historical account and town name to a precise geographical location, possible identification of a mine feature and a potential access route. Furthermore we achieved this in a matter of minutes and for free! We're not yet finished with our remote exploration as we must now plan the drone flight and assess car parking facilities. Google Streetview enables you to virtually drive around regional roads and assess the best access route and parking locations.
The Streetview survey has found a large amenity parking area just to the south-east of the mine location. This is a good area to park a vehicle and act as a take off point for the drone. Bing maps distance measurement indicate that the mine is only 300m away and there is direct line of site as per the Streetview imagery. This is well within the 1km range of the drone that will be used. We now have sufficient information to mount a expedition to the mine site.
6. Drone Deployment
On arrival at the parking spot we deploy the drone to assess the mine in significantly greater detail and to try and find other features that were not obvious on the satellite imagery. The drone being used is a DJI Phantom 2 with a GoPro Hero 4 and Zenmuse HD Gimbal Mount along with a First-Person View kit. There are vastly superior technologies available today at lower cost such as the DJI Mavic Pro. The Mavic is an ultra-compact foldable drone with up to 7km of range and can sustain a HD video link across this distance.
7. Ground Survey
The drone survey provides low altitude aerial imagery in super high resolution 4K detail. The feature of interest is now clearly identifiable as a flooded mine pit with a trench and a second satellite pit or shaft. The drone survey also indicates that this appears to be the only remaining mine feature at the site. We now have excellent information on the mine features and can approach the landowner for more details and access permission to perform a ground survey to collect samples and take photographs.
Twigspark Mine has now been completely captured and recorded for future generations. Recording the site from the air will enable future generations to easily relocate the site and a precise GPS reference will pinpoint the location of the pit. Though no significant minerals were found on this particular visit, it is clear how important this technology will be moving forward.
Additional Drone Applications
Photogrammetry
The above workflow is the most obvious application for mineral collectors. However, there are other important capabilities such as 3D photogrammetry and aerial mapping that are vitally important for recording localities for future generations.
Quarries, open pits and mines situated below the water table will flood. The shape and size of many historic pits has been lost to history as they are now under several hundred feet of water. Drone surveying enables the creation of interactive 3D models of pits and mines which will preserve them for all to see. Another useful feature for collectors is the ability to tag in 3D space the location of features of interest. This is vital in the case of vast open-pits which could take weeks to assess on foot.
Aerial Mapping
Modern drones can perform automated aerial mapping of large areas and the resulting photographs can be post processed into custom maps that can be overlaid onto maps environments like Google Earth.
Virtual Reality
3D photogrammetric models can be shared and viewed using online apps. For example, a recent model created by me of an Irish mine structure can be seen here: http://sketchfab.com/models/f7fe13e4276d44d7b7ea28968cb3f9cc . It is possible to interact with these models using standard VR devices like the Occulus Rift and HTC Vive giving a lifelike virtual presence on at the mine site. I have tested this functionality using my Occulus Rift CV1 and it works seamlessly with the Sketchfab app. Similarly, one can "teleport" around to different parts of the model and, presumably, it will be possible to walk around using whole room VR tracking in the future.
Conclusion
We have just scratched the surface on a number of groundbreaking new technologies that are set to totally revolutionise how we collect and prospect for mineral specimens. Of equal importance is the revolution in how we should record our finds and localities going forward into the future. With ever decreasing costs for storage and bandwidth there is no longer a barrier to capturing sites in unprecedented detail.
