understanding the namibian surficial environment · pdf fileunderstanding the namibian...
TRANSCRIPT
![Page 1: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/1.jpg)
Understanding the Namibian surficial
environment through the Regional
Geochemical Baseline Mapping
Programme
Gloria Simubali
Geochemistry and Laboratory Division
Geological Survey of Namibia
Ministry of Mines & Energy
5 November 2014
Earth Sciences for Namibia’s Sustainable Development
![Page 2: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/2.jpg)
• Geochemical baseline studies have been proved over the years in various countries as an important index in environmental assessment.
• At present the geochemical baseline of the Namibian land has not yet been fully defined.
• To fill this significant knowledge gap the Geological Survey of Namibia (GSN) embarked on a regional geochemical baseline mapping programme in 1999.
Earth Sciences for Namibia’s Sustainable Development
Introduction
![Page 3: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/3.jpg)
• The need to study and understand the
structure, composition and dynamics of
the Namibian landforms is driven by:
– The growing demands on mineral and energy
resources, water, soils and materials, problems
of pollution and waste disposal, and
vulnerability of human life to natural
anthropogenic hazards.
Earth Sciences for Namibia’s Sustainable Development
![Page 4: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/4.jpg)
• Regional Geochemical Baseline
Surveying Programme (RGSP) is a
development project solely funded by the
Government.
• Approx. 20,000 geochemical samples
collected from 8 (1:250,000 scale) map
sheets, namely Windhoek, Rehoboth,
Okahandja, Walvis Bay, Omaruru,
Fransfontein, Kamanjab and Tsumeb.
Earth Sciences for Namibia’s Sustainable Development
![Page 5: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/5.jpg)
Namibian
Landscape
Earth Sciences for Namibia’s Sustainable Development
![Page 6: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/6.jpg)
Index map
showing the
progress of
the rgsp
![Page 7: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/7.jpg)
• Some of the unique landmarks in Namibia, the Brandberg marking the highest point in altitude (2606 m above sea level)
![Page 8: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/8.jpg)
WHY THIS PROJECT?
• Sustainable development requires balancing of
many factors, including the health of the
environment and the utilisation of natural
resources, both of which require management
through a comprehensive high-quality
geochemical database.
• Knowledge of surface geochemistry is relevant
for economic and environmental management
decisions and policies for sustainable
development Earth Sciences for Namibia’s Sustainable Development
![Page 9: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/9.jpg)
Project Activities
• The RGSP has a number of stages involved: – Survey design and sample collection;
– sample preparation and analysis;
– data analysis and interpretation; and
– production of baseline geochemical maps for all possible
elements.
• Incorporation of all data and reports in the
National Geochemical Database
Earth Sciences for Namibia’s Sustainable Development
![Page 10: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/10.jpg)
Survey Design
The sampling surveys are designed on the basis of 1:250,000
scale map sheets
![Page 11: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/11.jpg)
1:50,000
scale
topographic
map
![Page 12: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/12.jpg)
1:50,000
scale
topographic
map with
sample sites
and
catchments
![Page 13: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/13.jpg)
Earth Sciences for Namibia’s Sustainable Development
![Page 14: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/14.jpg)
Sampling Contractors
![Page 15: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/15.jpg)
Sampling Equipment
![Page 16: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/16.jpg)
Sampling Process
![Page 17: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/17.jpg)
Sampling process
The composite sample
is screened (dry
sieving) in the field to
produce two size
fractions.
![Page 18: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/18.jpg)
Earth Sciences for Namibia’s Sustainable Development
Archival
Sample
Storage
Facility
![Page 19: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/19.jpg)
Monitoring
and Site
Inspections
![Page 20: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/20.jpg)
Monitoring
and Site
Inspections
![Page 21: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/21.jpg)
Site inspections involves checking whether:
• the sampling site is based on GSN coordinates
• Sample point marked correctly
• Peg have the correct sample number
• Aluminium tag is there with the correct numbering
Monitoring
Earth Sciences for Namibia’s Sustainable Development
![Page 22: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/22.jpg)
Sample preparation
Milling of samples
Sample Digestion
Pressed Pellets
and Glass
Beads for XRF
Sample solutions for ICP
![Page 23: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/23.jpg)
Sample analysis
WD-XRF
ICP-AES
Earth Sciences for Namibia’s Sustainable Development
![Page 24: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/24.jpg)
Sample analysis
ICP-AES
Earth Sciences for Namibia’s Sustainable Development
![Page 25: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/25.jpg)
Earth Sciences for Namibia’s Sustainable Development
![Page 26: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/26.jpg)
DATA processing
• Elements and oxides analysis:
– SiO2, Al2O3, TFe2O3, CaO, K2O, MgO, Na2O, MnO, P2O5, TiO2, Ag, As, Ba, Be, Bi, Cd, Ce, Cl, Co, Cr, Cs, Cu, Dy, Er, Eu, Ga, Gd, Ge, Hf, Ho, La, Lu, Li, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Sm, Sn, Sr, Ta, Tb, Th, U, V, W, Y, Yb, Zn and Zr.
– Multivariate geostatistical analysis method will be utilised to evaluate the analytical data.
– Data analysis, visualisation and preparation of the geochemical maps will be performed using Geosoft Geochemistry for ArcGIS.
Earth Sciences for Namibia’s Sustainable Development
![Page 27: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/27.jpg)
Summary 1 • Geochemical baseline is employed with the
understanding that:
– It represents a summation of natural and human influence.
– Indicates the actual content of an element in the superficial
environment at a given time.
• The data and the accompanying element distribution
maps resulting from systematically documenting the
concentration and spatial distribution of elements in
the surface can be a reference against which any future
changes can be quantified (Wang, 2012).
– As the climate changes, so does the environment
• Because the parent material strongly influences the soil
chemistry, a geochemical baseline should be
determined in separate geological regions (Darnley, 1997).
Earth Sciences for Namibia’s Sustainable Development
![Page 28: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/28.jpg)
Summary 2 • By sponsoring this project, the Namibian Government
acknowledges the economic development depends on
the environment and that continued environmental
degradation could threaten our actual survival.
• Since natural processes and human activities are
continuously modifying the chemical composition of
our environment, it is important to determine the
present abundance and spatial distribution of the
elements across the Namibian surface in a much more
systematic manner.
• The data generated through this project is expected to
aid exploration for mineral resources, earth science
research, environmental assessment and land use
planning in Namibia
Earth Sciences for Namibia’s Sustainable Development
![Page 29: Understanding the Namibian surficial environment · PDF fileUnderstanding the Namibian surficial environment through the Regional Geochemical Baseline Mapping Programme ... Geosoft](https://reader034.vdocuments.us/reader034/viewer/2022042600/5a78ad317f8b9ab8768e9aa2/html5/thumbnails/29.jpg)
Indeed Geology Underlies Everything!
Earth Sciences for Namibia’s Sustainable Development
Thank you!