Final EIAR - Aurecon AME Environmental | Environmental Projects

Proposed Wind and Solar (Photovoltaic) Energy Facilities on Kangnas Farm near Springbok in the Northern Cape: Final EIR 124
The ‘crater’ might therefore represent a pan developed at a depression where surface water
was unable to drain away as a result of the underlying structure. One other possible explanation
is the depression was caused by a meteorite impact. The Kalkkom Crater bears a superficial
resemblance to the Kalkkop Crater in the Easter Cape which was shown to be the result of a
meteorite impact about 250 000 years ago (Reimold et al., 1998). Although the crater shape at
Kalkkop is more obvious than at Kalkkom, this may be due to a difference in age or rate of
erosion. The meteorite origin of Kalkkop was only proved as a result of drilling, which
intersected shocked brecciated material below the base of the calcrete in the centre of the
crater (at > 90 m depth).
It was not possible to examine the bedrock that would have been the ‘target’ were this a
meteorite impact crater due to the lack of bedrock exposures as a result of a 10 m of calcrete
covering. According to Mr van Niekerk, the calcrete is typically about 10 m thick in the area, but
is at least 80 m thick in the large crater.
The only way to distinguish between these possible origins would be to undertake drilling
(preferable core drilling) in the centre of the crater through the calcrete into the underlying
bedrock.
b) Impact assessment
The construction phase of the wind and solar energy facilities would entail numerous,
excavations into the superficial sediment cover and in some areas into the underlying bedrock
as well. These include, for example, excavations for the proposed wind turbines and solar panel
foundations, underground cables, new electricity transmission line pylons and substations, as
well as new gravel access roads and any control / administrative buildings. In addition,
substantial areas of bedrock would be sealed-in or sterilized by infrastructure such as lay-down
and standing areas for the proposed wind turbines as well as new access roads. All these
developments may adversely affect fossil heritage within the projects’ footprint by destroying,
disturbing or permanently sealing-in fossils that are then no longer available for scientific
research or other public good.
Most surface rocks within study area are unfossiliferous but highly significant fossil material (e.g.
dinosaur and mammal remains) occurs at small, localized sites (buried crater lake and alluvial
deposits) within the site. Given the uncertainties concerning the patchy distribution of buried
fossil heritage, predicted impacts for the proposed wind and solar energy facilities are not
significantly different, and are considered unsure. However, these deposits are unlikely to be
directly affected except by deeper excavations (> 3 m 33 ) that penetrate the generally
unfossiliferous superficial deposits overlying them. The potential impacts on palaeontology from
both the proposed wind energy facility and solar energy facility developments are considered to
be of low intensity, local extent and long term and therefore of low (-) significance, with or
without mitigation. No difference in significance would result from the proposed wind or solar
alternatives.
33
It is possible that a number of the turbine foundations would be greater than 3 m deep. The
palaeontologist has indicated that this would not change the significance rating.
© Aurecon (2012) No unauthorised reproduction, copy
or adaptation, in whole or in part, may be made.
P:\Projects\108495 Kangnas WEF & PV EIA's\3 Project Delivery\4 Reports\FEIR\FEIR 210213 Final.doc