IAS 2002 Field Trip A6: Neoarchean Carbonates - Clues to Early Life and Early Ocean Chemistry

Dawn Y. Sumner (and James Bishop)


3.5 Billion Years of Sedimentation

Second Circular for the July 2002 IAS Meeting in South Africa (2.7 MB pdf file)


Page Contents:

Field Guide
Meeting Info
Dinner June 30
Letter with General Info
Suggested Reading

Digital version of the field guide:

Field Guide for IAS Trip A6 as a large (4.8 MB) PDF file.

Field Guide for IAS Trip A6 as a large (4.8 MB) Word98 file.

The stratigraphic column for Boetsap (Stop 6): Insert 1 (600 KB; PDF file; 11x17 inch paper)

The stratigraphic column for Kuruman Kop (Stop 7): Insert 2 (575 KB; PDF file; 11x17 inch paper)

Field photos showing some particularly good sites to see features numbered on the Boetsap stratigraphic column: Inserts 3, 4, and 5 (960 KB; PDF file; 3 pages on A4 paper) (top)


Information for meeting the field trip:

The excursion is scheduled for July 1 to July 6. We will be leaving from Johannesburg on the morning of July 1 at approximately 9:30 am. James Bishop (one of my graduate students, who is helping lead the trip) and I will be staying at the Holiday Inn Garden Court Sandton on the night of June 30 (corner Rivonia Road & Katherine Street Sandton Tel: +27-11-8845660 Fax: +27-11-7832004). You have two options for meeting us for the field trip.╩

1) You can meet us at the Holiday Inn Garden Court Sandton at 10 am. Please note that there are two Holiday Inn Garden Court hotels in Sandton and listed as conference hotels. Ours is the one on the corner of Rivonia Road & Katherine Street. We will probably be obvious in the hotel lobby, but we will also post a sign.

2) If you are staying at one of the conference hotels, one of us can pick you up earlier in the morning and take you to the Holiday Inn Garden Court Sandton. Obviously, we will need to arrange a time prior to the morning of July 1. We will also be meeting one participant at the airport on the morning of July 1. If you are planning to stay at a hotel near the airport, we can arrange to pick you up there as well. Please contact me in advance to arrange this pick-up. (top)

Dinner on June 30:

For those of you who are interested, James and I will be having dinner at the Holiday Inn Garden Court Sandton on the night of June 30 at 6 pm. Any of you who are interested are welcome to join us. We can arrange to pick you up the following morning at that time if you wish. (top)

The letter sent to participants on June 17:

Dear Members of the A6 Excursion:

Thanks for joining me on the excursion to explore Neoarchean Carbonates - Clues to Early Life and Early Ocean Chemistry. We currently have 15 people signed up for the trip, and it will be a lot of fun. I have posted the field excursion guide book online at http://www-geology.ucdavis.edu/~sumner/ias/ias.html for those of you who would like to look at it early. There are two large format stratigraphic columns that I will also have posted by the end of the week. The field guide has some references. I've also included a list of the most relevant ones at the end of this e-mail in case you would like to do some targeted reading on the long flight to Johannesburg (for many of you). I will have reprints of my papers to give you on the field trip.

The excursion is scheduled for July 1 to July 6. We will be leaving from Johannesburg on the morning of July 1 at approximately 9:30 am. James Bishop (one of my graduate students, who is helping lead the trip) and I will be staying at the Holiday Inn Garden Court Sandton on the night of June 30 (corner Rivonia Road & Katherine Street Sandton Tel: +27-11-8845660 Fax: +27-11-7832004). You have two options for meeting us for the field trip.

1) You can meet us at the Holiday Inn Garden Court Sandton at 10 am. Please note that there are two Holiday Inn Garden Court hotels in Sandton and listed as conference hotels. Ours is the one on the corner of Rivonia Road & Katherine Street. We will probably be obvious in the hotel lobby, but we will also post a sign.

2) If you are staying at one of the conference hotels, one of us can pick you up earlier in the morning and take you to the Holiday Inn Garden Court Sandton. Obviously, we will need to arrange a time prior to the morning of July 1. We will also be meeting one participant at the airport on the morning of July 1. If you are planning to stay at a hotel near the airport, we can arrange to pick you up there as well. Please contact me in advance to arrange this pick-up.

For those of you who are interested, James and I will be having dinner at the Holiday Inn Garden Court Sandton on the night of June 30 at 6 pm. Any of you who are interested are welcome to join us. We can arrange to pick you up the following morning at that time if you wish.

We will be driving to Kimberley on July 1, and we should arrive in time to spend an hour or two at the Kimberley Mine Museum and Big Hole, which records the early diamond mining history of Kimberley. It has a great display of uncut diamonds in addition to historical buildings, etc. We will stay at the Kimberley Holiday Inn Garden Court (http://www.sixcontinentshotels.com/holiday-inn?_franchisee=KIMSF) on the nights of July 1-3. On July 4 and 5, we will stay in the town of Kuruman at the Eldorado Hotel (Tel: +27 5373 22191 Fax: +27 5373 22191). We will return to Johannesburg mid afternoon on July 6, and we will take each of you to your conference hotel.

Breakfasts will be available at the hotels and typically consists of your choice of eggs, meat, toast, cereals, and fruit. Lunches will be packed into the field and will include fruit, sandwiches, cookies, juice, etc. If you have any special requests or dietary needs, please let me know. Dinners will be individually purchased at restaurants in Kimberley or Kuruman.

There are very few health concerns in the Northern Cape Province. It is winter, and night temperatures can get below 0íC, so there are essentially no mosquitoes nor typical tropical diseases like malaria, etc. Most of the snakes and scorpions are dormant and do not pose a danger with moderate care.

Daytime temperatures in the field can range from 5íC to 20íC (average temperature is above 10íC), and the area typically receives 7 mm of rainfall in July. Thus, I am planning to bring long pants, short sleeved shirts, a long sleeved shirt, a warm sweater, and a wind and water proof jacket. A wool hat, a sun hat, and gloves may also be useful. Boots are recommended for the excursion.

I will be leaving for South Africa on June 23 and will be in e-mail contact at least off and on until July 1. However, if you send me e-mail, you will get a message that I am out of town and won't reply until the end of August. I will definitely check my e-mail on June 30, and I will respond to any of you about field excursion logistics. You can also send a fax to me at the conference fax number. I will check for messages and faxes at RAU.

Cheers, Dawn (top)

Suggested Reading:

Stratigraphic Context:

BEUKES, N. J. (1987) Facies relations, depositional environments and diagenesis in a major early Proterozoic stromatolitic carbonate platform to basinal sequence, Campbellrand Subgroup, Transvaal Supergroup, southern Africa. Sedimentary Geology, 54, 1-46.

Boomplaas Formation:

BEUKES, N. J. (1977) Transition from siliciclastic to carbonate sedimentation near the base of the Transvaal Supergroup, northern Cape Province, South Africa. Sedimenary Geology, 18, 201-221.

Molar Tooth Structures:

JAMES, N. P., NARBONNE, G. M., and SHERMAN, A. G., 1998, Molar-tooth carbonates: Shallow subtidal facies of the Mid- to Late-Proterozoic, Journal of Sedimentary Research, 68:716-722.

Reivilo Formation and Facies:

BERTRAND-SARFATI, J. & ERIKSSON, K. A. (1977) Columnar stromatolites from the Early Proterozoic Schmidtsdrift Formation, northern Cape Province, South Africa--Part 1: Systmatic and diagnostic features. Palaeontologia Africana, 20, 1-26.

SUMNER, D. Y. & GROTZINGER, J. P. (1996b) Were kinetics of Archean calcium carbonate precipitation related to oxygen concentration? Geology, 24, 119-122.

SUMNER, D. Y. & GROTZINGER, J. P. (2000) Late Archean aragonite precipitation: Petrography, facies associations, and environmental significance. In: Carbonate Sedimentation and Diagenesis in the Evolving Precambrian World (Ed. by J. P. Grotzinger and N. P. James). SEPM Special Publication No. 65, p. 123-144.

Microbialites and the Gamohaan Formation:

SUMNER, D. Y. (1997a) Carbonate precipitation and oxygen stratification in late Archean seawater as deduced from facies and stratigraphy of the Gamohaan and Frisco formations, Transvaal Supergroup, South Africa. American Journal of Science, 297, 455-487.

SUMNER, D. Y. (1997b) Late Archean calcite-microbe interactions: Two morphologically distinct microbial communities that affected calcite nucleation differently. Palaios, 12, 300-316.

SUMNER, D. Y. (2000) Microbial versus environmental influences on the morphology of Late Archean fenestrate microbialites. In: Microbial Sediments (Ed. by R. E. Riding and S. M. Awramik), pp. 307-314. Springer Verlag, Berlin. (top)


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