ICDP Barberton Archean Surface Environments (BASE) Moodies Drilling Project, Moodies Group, Barberton Greenstone Belt

Introduction

Based on a proposal written by Profs Christoph Heubeck (Jena University) and Nic Beukes (University of Johannesburg), together with earth scientists from several other countries, the International Continental Drilling Program (ICDP) Consortium, with head office in Germany, has approved funding to drill eight diamond core holes into the rock succession known as the Moodies Group in the Barberton Greenstone Belt. The holes would vary between 300 – 500 m in depth with a total core length of some 3 km to be recovered.

Motivation for drilling

The ~3200 million year old rock beds of the Moodies Group represent  the world’s oldest known, well-preserved sedimentary succession with abundant deposits formed on land in fluvial (river) and aeolian environments. It also contains excellent examples of ancient soil profiles as well as intertidal deposits formed along the interface of continental and marine environments. The succession thus provides an ideal natural laboratory for studies to understand environmental and paleo-ecological conditions on land and intertidal areas during the early history of the world ~3200 million years ago. This was also the time during which the atmosphere was still reducing with free oxygen (the basis of modern life) either absent or just starting to be produced by oxygen-producing microbes (oxygenic photosynthesizers) and to accumulate in what is termed “oxygen oases” in the Early primitive oceans and atmosphere of the world some 3200 million years ago.

Studies of the Moodies Group could thus produce answers to intriguing questions like a) when and how our modern oxygen-rich atmosphere came in to being and b) when did oxygen dependant life forms developed i.e. the earliest precursors to modern mankind. These are also the type of questions that contributed to establishment of the Barberton Makhonjwa Mountain World Heritage Site (BMM-WHS)  and if they can be solved, could assist in attracting more national and international tourists to the area.

However, it is unfortunately so that modern weathering is quite intense in the Mountain Land. The result is that that certain components of the rocks, and especially organic carbon derived from ancient life forms, redox sensitive elements like iron and manganese, and minerals like iron sulphide (pyrite = fools-gold) and calcium carbonates have been altered or removed (dissolved) to several tenths of meters below surface by modern groundwater movement. In order to get fresh unaltered samples of these materials, one thus has to do core drilling to depths below the modern weathering front and that is the basic scientific reason for the drilling project

Location of Drill Holes 

The holes to be drilled are situated at 5 sites – of which the localities are as follows:

Site 1: Borehole BASE-1 in Elephants Kloof at Fairview Mine

Site 2: Borehole Base-2 at White Outcrop next to the paved parking lot „Tidal Sandstones“ of Geotrail on paved R40 in Mountainlands Nature Reserve

Site 3: Borehole BASE-3 on Oosterbeek 371 JU at “Hill 4” in Sappi forest area

Site 4: Boreholes BASE-4A, BASE-4B and BASE-4C All in close proximity to each other on Farm Oosterbeek 371 JU in Sappi Forest Area of the Lomati Valley.

Site 5: Boreholes BASE-5A and BASE-5B next to each other on the farm Belvue 711 JT along the eastern boundary of the Nkomazi Nature Reserve 

Topographic (Google Earth) map of the north-central Barberton Greenstone Belt, showing site locations. All sites except site 5 lie within about 12 km from Barberton.
Drill site BASE-2 at White Outcrop on Geotrail
Drill site BASE 4C on Oosterbeek in Lomati Valley

Drill Core Curation

One half of all the cores are to be curated at the National Core Storage Facility of the Council of Geosciences at Donkerhoek near Pretoria, and the other half at the core Facility of ICDP at the GFZ in Potsdam, Germany.

Meeting with drilling teams to discuss possible solutions to slow drilling advance and water losses in early stages of drilling
Onsite Geological Team documenting core descriptions and undertaking core splitting in background
Core marking and orientation by Chris Rippon in BIAS Hall

Capacity Building and Outreach

A major focus of the project and an ICDP requirement for the project is capacity-building and outreach. The fact that the operational part of the  project will take place in rural parts of South Africa presents us with a unique opportunity for public outreach to local schools and communities to explain the importance of the geological work that we will be conducting. The international nature of the project will expose those students that will be trained as part of the project to leading international scientists and research groups and their laboratories. The same applies for young academics that will be working on the project and the drill cores.

Educational displays in BIAS Hall
Visit by Geology students from UJ to drill site BASE 4A
Visit by CEO of Council of Geosciences and discussion with owners of Nkomazi Nature Reserve on drilling project
Meeting with local community leaders explaining purpose of drilling project
Prof Christoph Heubeck showing drill core to local school learners in BIAS Hall

Administration and Management of Project

The project is administered and managed under the umbrella of the DSI-NRF Centre of Excellence for Integrated Mineral and Energy Resource Analysis (CIMERA) under directorship of Prof Nikki Wagner.

The day-to-day management would be the responsibility of Profs Beukes and Heubeck with the onsite management of the drilling operations run by the geological drilling managers Rod Tucker and Chris Rippon with Dr Dora Paprika as Data Manager.

The drilling contractor is Master Drilling Exploration (Pty) Ltd

Environmental Controls

Proper Environmental Management Plans (EMPs) were prepared for the different drill sites with Tony Ferrar, a Consulting Ecologist from Barberton, acting as Environmental Control Officer

Contacts for More Information

Prof Nic Beukes
DSI-NRF CIMERA and UJ Geology Department
e-mail: nbeukes@uj.ac.za
Cellphone: +27 (0) 82 807 5037

Prof Christoph Heubeck
Jena University
e-mail: christoph.heubeck@uni-jena.de
Cellphone: +27 (0) 82 254-1318
Telephone Jena: +49 (0) 3641-948620

Funders