Early Earth geology of the Barberton greenstone belt, Sunday 1 to Thursday 5 November 2020
Vredefort Dome impact structure, Wednesday 11 November (part of conference programme)
Square Kilometer Array (SKA) telescope site, Sunday 15 to Tuesday 17 November 2020
Early Earth geology of the Barberton greenstone belt
The 3.55-3.2 billion-years-old Barberton greenstone belt in South Africa has emerged as one of the classic Archaean geological sites worldwide in which to study early Earth history. The Onverwacht Group, the type locality of komatiite, is a thick pile of submarine lava flows that erupted intermittently over a time period of 250 Ma. Breaks in volcanic activity resulted in the deposition of sedimentary units characterized by predominantly volcaniclastic material and chemical precipitates. A rich microbial ecosystem is preserved as filamentous and spherical structures of carbonaceous matter and microbial mats in cherts. Traces of life are associated with rocks that show evidence for hydrothermal activity on the ocean floor. Submarine hydrothermal systems, driven by circulation of seawater through volcanic rocks, constitute a likely site where life emerged and evolved. Higher up in the stratigraphy of the Barberton greenstone belt, sedimentary rocks dominate in the 3.25 billion-years-old Fig Tree and Moodies groups. Here, banded iron formation provide constraints on the composition of the Archaean ocean. Sandstones deposited on tidal flats host well preserved shallow-water sedimentary structures and remnants of microbial mats. An array of granitoid rocks and evidence for polyphase events of deformation and metamorphism has a bearing on tectonic processes unique to the Archean geological record.
Dates: Sunday 1 November (7:30) to Thursday 5 November (18:00)
Accommodation: Forever Resort (Badplaas), Diggers Retreat (Barberton)
Field trip leaders: Axel Hofmann, Phumelele Mashele, Chris Rippon
Excursion fee: ZAR 6500 (sharing accommodation), ZAR 8000 (single accommodation)
Notes: The fee includes transport, basic accommodation, and basic meals. Days will be hot and dry, although afternoon thundershowers may occur. Some sites will require hiking for 2-3 km. Forever Resort has pools fed by hydrothermal springs, so bring swimming trunks/costumes. On the last day people can be dropped in Nelspruit for potential self-arranged onward travel to Krueger Park.
Transport: transport will be in four-wheel-drive vehicles and minibuses. The trip will start and end in Johannesburg. Pick-up and drop-off points will be in Auckland Park/Melville and OR Tambo airport.
Maximum number of participants: 25
Sunday, 1 November 2020
Travel from Johannesburg to Badplaas (morning); overview of the geology of the Onverwacht Group and 3.53 Ga volcanic sequence of the Theespruit Formation (afternoon); overnight in Badplaas.
Monday, 2 November 2020
Travel to Songimvelo Nature Reserve; 3.4 -3.3 Ga volcano-sedimentary rocks of the Komati River section (morning); Game Drive in Songimvelo Nature Reserve (afternoon); overnight in Badplaas.
Tuesday, 3 November 2020
Travel to Barberton; visit of Geotrail en route; sedimentary rocks of the Fig Tree and Moodies Groups; overnight in Barberton.
Wednesday, 4 November 2020
Buck Reef Chert or Barite Valley (to be confirmed); overnight in Barberton.
Thursday, 5 November 2020
Visit of Sheba Gold Mine and Moodies Group; in afternoon return to Johannesburg
Half-day excursion of the Vredefort Dome
The Vredefort structure is centred some 130 km to the southwest of Johannesburg. The central part of the Vredefort structure, the Vredefort Dome, represents the central uplift of a ~250 km crater that formed 2.02 billion-years-ago following the impact of a ~15 km bolide. The Vredefort Dome has been the focus of scientific interest for well over a century. In particular, the Vredefort Dome is important as it (1) has spectacular, impact-generated rock deformation phenomena, which have long indicated a cataclysmic origin of the Dome; (2) represents a unique window into the upper and middle crust of an Archean craton; (3) forms the centre of the Witwatersrand Basin, the world’s largest gold deposit.
11 November 2020
Pseudotachylitic breccia in Archaean basement granite
11 November 2020
11 November 2020
Dates: Wednesday 11 November 2020
Field trip leaders: Roger Gibson
Excursion fee: no extra fees for registered conference participants
Notes: the trip will require short walks; a 30 min introductory talk on the Vredefort impact event will be given to interested participants on the previous day to provide an overview and to introduce the sites to be visited on the following day.
Field trip to the Square Kilometre Array (SKA) telescope site in Carnarvon, Sunday 15 November to Tuesday 17 November
The Square Kilometer Array (SKA) is an international, flagship astronomy facility consisting of the largest radio telescope ever constructed. Eleven member countries are funding the thousands of radio dishes that will be located in Africa and Australia, having a total collecting area of one square kilometre (one million square meters), at a first-phase cost of 674 million euros. SKA operates over a range of frequencies and will return unprecedented resolution and sky coverage. Science projects include tests of general relativity through observations of pulsars and gravitational waves, studying the epoch of reionization (the time between hydrogen/radiation decoupling and the Universe’s first light), observing galaxy formation and evolution, and searching for signatures of extraterrestrial life.
The SKA site in South Africa is in the Karoo, near the small town of Carnarvon. This site will host the core of the high- and mid-frequency radio dishes, with outstations in other parts of South Africa as well as in Botswana, Ghana, Kenya, Madagascar, Mauritius, Mozambique, Namibia and Zambia. Carnarvon is high, dry, and exceptionally radio-quiet, far away from machines that emit radio waves. Although located remotely, the SKA state-of-the-art technology is expected to produce 11 exobytes of data per day (an exobyte = one billion gigabytes). The precursor project, 64-dish MeerKAT, is completed and undergoing verification testing. SKA itself is expected to have initial observations in 2022.
The SKA Carnarvon site tour lasts approximately 5 hours and includes the following:
- Tour of the Karoo Array Processing Building and power plant
- Visit to KAT-7 (Karoo Array Telescope), 7 dishes of 14-m diameter, an engineering and science testbed for MeerKAT
- Visit to HERA (Hydrogen Epoch of Reionisation Array), an array of 331 fixed-pointing antennas, each 4-m diameter, operating at low frequency of 100-200 MHz
- Visit to MeerKAT, 64 dishes of 13.5-m diameter, precursor to the SKA
- Visit to the SKA prototype
Dates: Sunday 15 November (8:30) to Tuesday 17 November (18:00)
Accommodation: Lord Carnarvon Guest House
Field trip leader: Nicolas Erasmus, South African Astronomical Observatory
Excursion fee: ZAR 6000 (single accommodation)
Notes: The trip will start and end in Cape Town. The excursion fee includes transport, accommodation, and meals. Because of the strict no-RF zone of the SKA site, no cameras, phones, or smart watches etc. will be allowed on the day of the tour. The SKA site is also a national key point, so participants will be required to undergo a pre-security screening a few weeks before the tour by providing South African ID or passport information.
Transport: Transport will be in minibuses. The pick-up and drop-off point will be at SAAO (https://goo.gl/maps/FhE64toKRS7kA6Bk6) in Cape Town. Travel to Cape Town has to be self-arranged.
Number of participants: 8 (minimum) to 24 (maximum)
Sunday, 15 November 2020
Shuttles depart at 8:30 from Cape Town (SAAO) and arrive in Carnarvon that evening. The route will be via Clanwilliam and Calvinia and will take approximately 8 hours.
Monday, 16 November 2020
Tour of the SKA site which will include a BBQ-style lunch on site.
Tuesday, 17 November 2020
Shuttles depart at 8:00 from Carnarvon and return to Cape Town by 18:00. An airport-drop-off can be arranged.
Namib-Naukluft National Park, Namibia
This tour is designed to offer the participants an opportunity to experience the beauty and complexity (both biological and geomorphological) of one of the world’s oldest hot deserts. The theme will be principally biological (the tour leader is a biologist!), with an emphasis on the existence of cryptic microbial communities and the adaptation of organisms to extremes of heat and desiccation. The tour also offers the participants unique access some of the more specialised and unusual aspects of the Namib Desert, include the enigmatic Welwitschia mirabilis, stone-age tribal artefacts and fossilized examples of ancient dune biology.
Registrants for the Astrobiology2020 conference are invited to participate in a post-conference tour to the Namib Desert. The tour group has limited capacity and selections will be on a ‘first come, first served’ basis. The minimum number of participants is 4, with a maximum of 8. This ‘event’ will be cancelled (and monies paid refunded) if the minimum number of people is not reached.
The tour will be led by Don Cowan. Don is a Professor in the Department of Biochemistry, Genetics and Microbiology at the University of Pretoria, and has been working on the microbial ecology of the Namib Desert for the past 10 years. One of his interests is the structure and function of microbial communities which are found underneath quartz pebbles (hypoliths), one of the many models for the survival of life on Earth and elsewhere.
Departure and Return
The tour group will meet at 08:00h on 14 November in the OR Tambo International Airport departures area (prior to check-in at the SA Airlink desk). It is the participant’s responsibility for arranging overnight accommodation for November 13. We recommend staying at one of the several hotels available at the airport.
Flight bookings (Johannesburg to Walvis Bay, return, or onward travel) are the responsibility of the participant. At the end of the tour, tour members should make their own arrangements for onward travel.
Saturday, 14 November 2020
10:20 flight from Johannesburg (SA Airlink SA8141: OR Tambo International Airport) to Walvis Bay International Airport, Namibia: 21/2 hours. Ground transport from Walvis Bay to collect National Park Access Permits, and to Gobabeb Research and Training Centre (2 hr). Registration and Room assignment; relaxation time; dinner, orientation session.
Sunday, 15 November 2020
Local travel (gravel plains: focus on geology, biology)
Monday, 16 November 2020
Local travel (Namib Sand-Sea: focus on geology, geomorphology, fossils): Maybe a ‘night in the dunes’.
Tuesday, 17 November 2020
Local travel (gravel plains: focus on hypersaline springs)
Wednesday, 18 November 2020
09:00 departure from GNRI for Walvis Bay international Airport; 13:40 departure from Walvis Bay for OR Tambo International Airport (SA Airlink SA8142) or self-arranged travel.
Costs are calculated on the basis of all ground transport in Namibia, accommodation for 4 nights at GNRI (single or sharing), Gobabeb staff support costs, conservation fee and all meals.
Tour cost per person (shared room): R9,760 (approx. $US660)
Tour cost per person (single room): R10,560 (approx. $US720)
Excluded costs include Jo’burg-Walvis Bay return flights, visa costs (if applicable), alcoholic beverages and soft drinks at GNRI.
Accommodation: The GNRI is a fully established field station, with comfortable accommodation (linen and towels supplied). For more information, see www.gobabebtrc.org.
Meals: We use a local on-site catering service for all meals. Hendrik (our caterer) can accommodate a range of dietary preferences.
Visas: We enter Namibia as tourists, where no-cost visa-on-entry regulations apply. However, some nationalities are not eligible for the visa-waiver scheme (e.g., China, India, Nigeria and others). It is the applicant’s responsibility to ascertain the category of their passport, and to apply for a visa through their local embassy if necessary.
Weather: The tour is scheduled for early summer. Temperatures may rise to around 40oC at mid-day.
Security: There are no security issues. The Namib region is a non-malarial area.
Registration for training school and field trips closes on 31 June 2020