Cenozoic Regional Erosion of the Abyssal Sea Floor Off South Africa

1984 ◽  
Author(s):  
Brian E. Tucholke ◽  
Robert W. Embley
Keyword(s):  
South Africa ◽  
Sea Floor

scholarly journals 3.5-Ga hydrothermal fields and diamictites in the Barberton Greenstone Belt—Paleoarchean crust in cold environments

2016 ◽  
Vol 2 (2) ◽  
pp. e1500368 ◽  
Author(s):  
Maarten J. de Wit ◽  
Harald Furnes
Keyword(s):  
South Africa ◽  
Sea Level ◽  
Volcanic Rocks ◽  
Hydrothermal Systems ◽  
Hydrothermal Fluids ◽  
Sea Floor ◽  
Cold Environments ◽  
Barberton Greenstone Belt ◽  
Mineral Growth ◽  
Hydrothermal Fields

Estimates of ocean temperatures on Earth 3.5 billion years ago (Ga) range between 26° and 85°C. We present new data from 3.47- to 3.43-Ga volcanic rocks and cherts in South Africa suggesting that these temperatures reflect mixing of hot hydrothermal fluids with cold marine and terrestrial waters. We describe fossil hydrothermal pipes that formed at ~200°C on the sea floor >2 km below sea level. This ocean floor was uplifted tectonically to sea level where a subaerial hydrothermal system was active at 30° to 270°C. We also describe shallow-water glacial diamictites and diagenetic sulfate mineral growth in abyssal muds. These new observations reveal that both hydrothermal systems operated in relatively cold environments and that Earth’s surface temperatures in the early Archean were similar to those in more recent times.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Combining Professional Interests and Travel: People to People Citizen Ambassador Program

2011 ◽  
Vol 1 (2) ◽  
pp. 47-54
Author(s):  
Alex Johnson ◽  
Amanda Hitchins
Keyword(s):  
South Africa ◽  
Health Education ◽  
Communication Disorders ◽  
Social Conditions ◽  
Speech Language Pathologists ◽  
Exchange Program

Abstract This article summarizes a series of trips sponsored by People to People, a professional exchange program. The trips described in this report were led by the first author of this article and include trips to South Africa, Russia, Vietnam and Cambodia, and Israel. Each of these trips included delegations of 25 to 50 speech-language pathologists and audiologists who participated in professional visits to learn of the health, education, and social conditions in each country. Additionally, opportunities to meet with communication disorders professionals, students, and persons with speech, language, or hearing disabilities were included. People to People, partnered with the American Speech-Language-Hearing Association (ASHA), provides a meaningful and interesting way to learn and travel with colleagues.

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