Geological Mapping Experience and Skills

Field mapping experience

1:10,000 scale feature-mapping training area near Chesterfield, UK

British Geological Survey (BGS) mapping training is an essential prerequisite for detailed geological mapping in the UK, successfully completed by Richard in glacially-stripped Carboniferous stratigraphy.

The Publications list includes numerous regional and detailed geological maps, and just three examples are given here to illustrate the depth of Richard's experience.

spacer BGS

1:5000-scale mapping of felsic dyke swarms in Hong Kong - published map (Discovery Bay, Lantau) and detailed field notes (Peng Chau)

Reference: LANGFORD R L, JAMES J W C, SHAW R, CAMPBELL S D G, KIRK P A and SEWELL R J (1995). Geology of Lantau District, 1: 20 000 Sheets 9, 10, 13 and 14. Hong Kong Geological Survey Memoir No 6. Geotechnical Control Office, Hong Kong, 173 p

Lantau Notes

Wiluna 1:100,000 GSWA mapping; approx 8x11km

Reference: LANGFORD R L, WYCHE S and LIU S F (2000). Geology of the Wiluna 1:100 000 sheet. Western Australia Geological Survey, 1:100000 Geological Series Explanatory Notes 26p

GSWA

Bangemall regional mineralisation mapping; approx 50x70km

Reference: COOPER R W, LANGFORD R L and PIRAJNO F (1998). Mineral occurrences and exploration potential of the Bangemall Basin. Western Australia Geological Survey Report 64, 42 p

Bangemall

Field mapping innovations

Classical geological mapping involves the integration of concise field observations with the interpretation of the connection between geological processes and landforms.

Making notes and recording field observations used to rely heavily on topographic maps and aerial photographs, with positions derived from compass bearings and dead reckoning. GPS is now so accurate (typically around 10m) that positioning is very fast and reliable, with the right tool.

Not surprisingly, many geologists now find using paper notebooks is a laboured process. One temptation may be to use your GPS for recording, or you may be searching for the biggest, strongest laptop. The advent of Android-based tablets and numerous free or low cost apps provides a more elegant, and cheaper solution.

There are three tools that Richard has used in recent geological mapping that can now speed up the process:

  • Android GPS-enabled super bright-screen tablet (Samsung Galaxy Tab 7.7)
  • OruxMaps software
  • RockLogger software

There are many more hardware and software tools in use or being developed, which should lead to further mapping efficiencies. These three are Richard's personal choice (at the moment).

Hardware

Look at hardware as expendable, and focus on a few critical parameters, with external backup as a safeguard. Android apps seem to be more suited to geological mapping than Apple, and Windows will have the apps at a cost.

Focus on getting the absolute brightest (high nit) screen you can find, then look at screen size and camera resolution.

1. Screen brightness. This is the most important factor, because if you can't see the screen in sunlight or bright shade, forget it; the tablet will end up being a major frustration. The brightest on the market in mid-2012 was the Samsung Galaxy Tab 7.7 (600 nits). The Panasonic Toughpad 7-inch FZ-M1 features a daylight-readable (500-nit) screen, but uses Windows software. The Samsung Galaxy Not 10.1 (2014) has a 430 nit screen, so keep looking for improvements.

2. Screen size. You can double up and use a phone mapping tablet, but a 5” phone is a bit small for mapping, and a 7” tablet is a bit big for a phone. So, although it is tempting, keep the two functions separate, and get a tablet with either a 7”, 8” or 10” screen. The choice is largely personal, as even the 7” won't fit in your back pocket.

3. Camera resolution. You can give up on a separate camera and just use the tablet. The Tab 7.7 only has a 3MP camera, which sounds terrible when compared with the average digital camera. However, it takes excellent pictures, and there is a low cost app that allows you to take HDR pictures. At the worst, it provides a good backup to a conventional camera, and geotagging is automatic.

4. Ruggedisation. An SSD has no moving parts, so is a good choice, and if you can find something with a stronger hinge (if a laptop), then good. However, a keyboard can be protected with a sheet of thin plastic, and do you really need to protect a screen if it is not being touched? A field tablet may have few chips on it, but a simple protective case is all that is needed... plus a bit of TLC.

5. Power. Be sure that you know the power limitations of your mapping and logging gear. The Samsung 7.7 can run for a day and a half, and a good laptop for most of the day. Keep an external power supply such as a USB battery pack as back-up for the tablet and mobile phone.

Software

OruxMaps Navigation

OruxMaps can be used with your own images (orthophotographs, remote sensing, geophysics...) as a mapping backdrop You can use the OruxMaps Windows desktop version for conversion.

OruxMaps is free, although it has the option to make a personal donation to the developer.

This screen image shows the complete OruxMaps mapping for an oolitic ironstone ridge; it does not show all the other data acquired using RockLogger.

Each pin is an annotated waypoint, which is typically a quick and simple note taken during a traverse. If you have a complex observation, use RockLogger, but if it is a simple note, use an OruxMaps waypoint.

The blue, purple and red lines are traverses for each of the three days mapping. The background is a GE image, downloaded before mapping started.

Hells Gate

RockLogger Field Notes

This app is free for restricted use, and about $9 to unlock all restrictions. RockLogger records the dip, strike, GPS position, structure type, rock type and field notes, so it is about as good as you can get.

Simply place the tablet flat against the surface to be measured, and press the screen button. All of these data are in a simple CSV file that can go straight into MapInfo or a database.

RockLogger data RockLogger RockLogger

Geotagging

If you want to add value to field photographs taken with a normal digital camera, adding the GPS location is one option. There are lots of programs to do this and, perhaps not surprisingly, Richard has tried lots.

GeoSetter is a very good, map-based, with lots of control, including moving photos around on the map and getting them re-tagged if you don't like the result.

All you need is a GPX file from your GPS or Tablet (OruxMaps gives you this) and the correct time on your camera. Make sure the GPS logging interval is pretty tight (5m and/or 2 seconds).

The best way to view geotagged photographs is in Google Earth - click here to see this example from Wolfe Creek Crater.

Wolfe Creek

HDR Field Photography small hand

Shoreline outcrops at Cockle Creek, southern Tasmania, show how High Dynamic Range (HDR) photography can improve your pictures. Click these links to see a detailed explanation and examples of HDR used for field and core photography.

Right: HDR processed three bracketed images

Below: Single image

Cockle Creek natural

Cockle Creek

Caveat: Richard's recommendations above are based on his personal experience, and are not meant as product endorsements. These recommendations are likely to change over time as better tools become available. If you have experience with any good geological mapping hardware or software, please let him know.