<< Previous Next >>

From Ice to Fire 20 - Dolerite Dyke

From Ice to Fire 20 - Dolerite Dyke
Photo Information
Copyright: Neels Gunter (corjan3) Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 430 W: 49 N: 964] (4707)
Genre: Landscapes
Medium: Color
Date Taken: 2014-09-27
Categories: Mountain
Exposure: f/13.0, 1/640 seconds
More Photo Info: [view]
Photo Version: Original Version
Date Submitted: 2014-10-02 12:57
Viewed: 2059
Points: 16
[Note Guidelines] Photographer's Note
The 20th in the series under the title FROM ICE TO FIRE - A 200 MILLION YEAR JOURNEY BETWEEN TWO DESERTS. To follow the whole story, one would have to start with Image 1.

It is the year 183 million before present and Mother Earth heaves her bosom. The supercontinent Gondwana, until recently in compressive regime, goes into a dilatational state and starts cracking. Fissures open, forming pathways for basaltic magma to enter from below and flow out onto the surface of the Earth which was several kilometres higher than the present-day surface seen here. Where the magma cooled and solidified below the surface by crystallization in such fissures, dykes of dolerite rock were formed.

Numerous dolerite dykes exist in South Africa and they are excellent localisers of groundwater below the water table. Large parts of the country that were too dry for permanent human habitation were made accessible by drilling boreholes into the fractured (brecciated) zones along the dykes where good sources of downseeped meteoric water exist. The dyke in the photo is less than two metres wide but they can be several tens of metres in width and more than 50 km long. Dykes that are not visible on the surface can often be detected by a row of trees growing along its length and with a sensitive magnetometer as dolerite contains the mineral magnetite.

oscarromulus, PeterZ, lousat, ramthakur, Hotelcalifornia, peter_stoeckl has marked this note useful
Only registered TrekNature members may rate photo notes.
Add Critique [Critiquing Guidelines] 
Only registered TrekNature members may write critiques.
ThreadThread Starter Messages Updated
To tuslaw: Groundwatercorjan3 1 10-04 19:51
You must be logged in to start a discussion.

Critiques [Translate]

It's ALWAYS a sincere pleasure to visit your page/s.
Of course, the images are most lovely and to the point.
The best part is: WHAT AN EDUCATION!!!
Most kind regards from Canada from Mario.

  • Great 
  • PeterZ Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 5137 W: 166 N: 13121] (49139)
  • [2014-10-02 14:16]

Hello Neels,
Great respect for the way you match all these beautiful photos to your interesting notes.
Remarkable photo in natural colours. Surprising to see such a dolerite dyke.

  • Great 
  • lousat Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 6595 W: 89 N: 15659] (65489)
  • [2014-10-02 15:19]

Hi Neels.This photo is one of the best and most interesting parts of your series, it seems that you've cut the rock, dividing it for us to see all the work done by the time in different eras, fine details and natural colors.Have a nice weekend and thanks,Luciano

Neels, you have been giving us a deep insight into the history of earth through your images of rocks you have explored intensively in your country.
This is yet another significant step in your exploration. I enjoy reading your notes immensely.

Hello Neels - Another important picture. Like to go through your NOTE. Well details. Thanks for sharing. Regards - Srikumar

Hello Neels,
Nice to see your images. Remarkable photo and comments. The rocks have wonderful natural colors. Very nice photo taken from a very good POV.
Thanks for sharing!

Ciao Neels, fascinating landscape, excellent clarity, wonderful colors and splendid light, very well done, my friend, have a good week end, ciao Silvio

  • Great 
  • tuslaw Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 2754 W: 282 N: 4931] (19883)
  • [2014-10-04 18:09]
  • [+]

Hello Neels,
How interesting to view this obvious stress fracture in the earths crust. Even more interesting is how they can be used to find water reservoirs below the surface. Nicely photographed showing good detail, color and exposure.

Calibration Check