The listed waypoint will take you in front of the security gate
of Durnacol – you will have a closer view of the coal heap and
there is no need to enter the mining area. Waypoint one S28 03.728
E29 58.662 and Waypoint two S28 04.732 E29 58.722 will take you to
mine dumps that are in the process of rehabilitation.
Durnacol
Durnacol is a small rural town in the central part of
KwaZulu-Natal, South Africa. The name is an acronym for Durban
Navigational Collieries, a mine that was opened at the turn of the
20th century. The mine mainly produced coking coal for the shipping
industries, but later the coal was used in the smelting of iron.
The mine ceased production activities in 2000. At present the area
on the mine property is being rehabilitated and is being managed by
the local municipality.
Origin of Coal in KwaZulu-Natal:
Coal has been defined as “a compact stratified mass of mummified
plants”. The plant that eventually formed South African coal grew
some 250 – 300 million years ago in the latter part of the
Palaeozic “Permian” age.
250 million years ago South Africa was in the grip of a great ice
age. Glaciers advanced and retreated over an immensely long period
of time creating valleys, swamps, and peat bogs and depositing
fertile glacier soil known as till. Here vegetation began to form
when the ice retreated. When the ice advanced the vegetation was
buried. As this process repeated itself layers of vegetation were
deposited under succeeding layers of later sediments. In the
immensely long interval between the growth of coal plants and the
mining of coal, the plant debris was transformed in a process known
as coalification.
The submerge plants and plant debris first rotted and the under
went biochemical changes to be transformed into peat. The passage
of time, together with the pressure and heat produced by the great
thickness of later sediments, completed the change into the
familiar banded or Humic Bituminous coal of industry.
Ages of Coal:
The various stages of coal are formed by the amount of heat to
which the rock has been subjected.
- PEAT – Youngest form of coal
- LIGNITE – Brown coal
- SUB – BITUMINOUS
- BITUMINOUS
- SUB – ANTHRACITE
- ANTHRACITE – The oldest form of coal
The three main coal bearing areas of Northern Natal are;
- The Klipriver field, stretch – “top” and the “bottom” seams,
often closely spaced and ranging in thickness from 1.1–1.5 meters.
As the depth of these seams often ranges 170–300 meters, access to
the coal is via vertical shafts and in some cases inclines
shafts.
- In the Utrecht and Vryheid fields, the latter running in a line
east of Vryheid from Paulpietersburg south to the Enyati Hills,
four seams are commonly found and are known as the Alfred, Gus,
Dundas and Coking seams. Ranging in thickness from 0.7–1.8 meters,
these seams outcrop in the flanks of isolated mountain masses.
Access is direct by means of horizontal adits driven into the
hillsides.
Where the coal seams are significantly close to the surface,
open cast mine techniques are used where by the overlaying earth is
stripped away. Most Natal Collieries have small open cast sections
and indeed this technique was first pioneered in South Africa at
the Hlobane Colliery in Natal.
A characteristic feature of the Natal Coal Fields is the presents
of anthracite, the final stage in the process of coalification. At
a time when large volumes of lava where being poured from the
fissures of the earth to build the famous Drakensberg Mountains,
some of the molten rock was forced into the coal-bearing strata of
the earth, raising the temperature considerably, removing the
volatile properties of the coal in places and burning it in others.
The molten rock hardened into Dolerite forming sills which overlay
and underlay the coal seams, and even intersected the seams in the
form of dykes.
To qualify for logging this cache, please attached the photos in
the listing and e-mail the cache owner the answers of the questions
listed below:
- Take a picture of your GPS’r at the listed waypoint with the
coal heap in the background (you do not need to enter through the
gate of the mine area), and post it in your log with a description
if you find the coal heap smoldering or not.
- Name two methods to prevent or minimize the risk of coal dust
explosions in coal mines?
- Methane gas (CH4) commonly known as firedamp was produced
million of years ago by decaying vegetable matter. Which important
device was developed in 1815 to measure the concentration of
methane gas in the coal mines to prevent explosions?
- At waypoint one and two you will see rehabilitation mine dumps
from the road – describe the difference in completion of
rehabilitation between the sites and if you feel the process will
be successful on not?