Intimations on the Tertiary vegetation of southern Africa

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 345-354 ◽  
Author(s):  
J. A. Coetzee
Keyword(s):  
Southern Africa ◽  
Major Change ◽  
Pollen Record ◽  
Vegetation Shifts ◽  
Ice Cap ◽  
Tropical Vegetation ◽  
Cape Peninsula ◽  
Benguela Current ◽  
And Migration ◽  
The Antarctic

Fossil pollen sequences from the Cape Peninsula and the Saldanha region indicate that sub tropical vegetation and climates existed in these regions during the Miocene. The pollen record from the Cape Peninsula may point to the extinction of some taxa by the terminal Miocene/Early Pliocene with the subsequent strong development of macchia. This major change can probably be related to the maximum build-up of the Antarctic ice-cap in the latest Miocene and the accompanying profound palaeoceanographic changes such as the major cooling of the Benguela current with its effect on the aridification of the Namib desert, and the global glacio-eustatic sea level drop.Parallel palynological and lithological studies in the Saldanha region show that prominent Miocene vegetation shifts were linked to profound local changes in the palaeoenvironment associated with the northward migration of the Miocene Berg River. Such studies are of paramount importance for the possible assessment of the causes of changes in the palaeoenvironment and should first be carried out at many more sites over a wide region. It is to some extent premature to draw firm conclusions as to the origin and migration of some taxa in southern Africa. The record of very primitive angiosperms such as the ClavatipolleniteslAscarina complex and Winteraceae is of considerable phytogeographic interest.

Ice-Core Pollen Record of Climatic Changes in the Central Andes during the last 400 yr

2005 ◽  
Vol 64 (2) ◽  
pp. 272-278 ◽  
Author(s):  
Kam-biu Liu ◽  
Carl A. Reese ◽  
Lonnie G. Thompson
Keyword(s):  
Little Ice Age ◽  
Ice Core ◽  
Climatic Changes ◽  
Ice Age ◽  
Striking Similarity ◽  
Pollen Record ◽  
Dry Period ◽  
Proxy Records ◽  
Ice Cap ◽  
Ice Accumulation

AbstractThis paper presents a high-resolution ice-core pollen record from the Sajama Ice Cap, Bolivia, that spans the last 400 yr. The pollen record corroborates the oxygen isotopic and ice accumulation records from the Quelccaya Ice Cap and supports the scenario that the Little Ice Age (LIA) consisted of two distinct phases�"a wet period from AD 1500 to 1700, and a dry period from AD 1700 to 1880. During the dry period xerophytic shrubs expanded to replace puna grasses on the Altiplano, as suggested by a dramatic drop in the Poaceae/Asteraceae (P/A) pollen ratio. The environment around Sajama was probably similar to the desert-like shrublands of the Southern Bolivian Highlands and western Andean slopes today. The striking similarity between the Sajama and Quelccaya proxy records suggests that climatic changes during the Little Ice Age occurred synchronously across the Altiplano.

The United Nations and Antarctica, 1994: the restoration of consensus?

Polar Record ◽  
1995 ◽  
Vol 31 (179) ◽  
pp. 419-424 ◽  
Author(s):  
Peter J. Beck
Keyword(s):  
United Nations ◽  
Major Change ◽  
International Community ◽  
Consensus Approach ◽  
Future Role ◽  
Change Of Direction ◽  
Antarctic Treaty ◽  
Environment And Development ◽  
The Antarctic ◽  
First Time

ABSTRACTThe twelfth successive UN session on the ‘Question of Antarctica,’ held at the close of 1994, saw a major change of direction. One brief session of the First Committee, followed by the General Assembly's adoption of resolution A49/80 without a vote, signified the restoration of a consensus approach towards the ‘Question of Antarctica’ for the first time since 1985. Resolution A49/80 stressed the need for Antarctic Treaty Parties (ATPs) to meet commitments undertaken at the 1992 United Nations Conference on Environment and Development, and particularly to continue providing the wider international community with information about Antarctic developments. The ‘Question of Antarctica’ will not be placed on the UN agenda again until 1996, thereby breaking the sequence of annual UN discussions started in 1983. On the surface, consensus was restored, but it is debatable how far the outcome represented merely a papering over of the cracks rather than the basis for an enduring solution to the problems dividing ATPs and their critics. The key point at issue remains the nature and extent of the UN's future role in Antarctic affairs, particularly as ATPs will only accept a limited UN role performed within the context of the Antarctic Treaty System.

New trigonioid bivalves from the Early Jurassic to earliest Cretaceous of the Antarctic Peninsula region: systematics and austral paleobiogeography

1995 ◽  
Vol 69 (1) ◽  
pp. 66-84 ◽  
Author(s):  
Simon R. A. Kelly
Keyword(s):  
New Zealand ◽  
Antarctic Peninsula ◽  
Southern Africa ◽  
Late Jurassic ◽  
Early Jurassic ◽  
South Shetland Islands ◽  
Shetland Islands ◽  
Livingston Island ◽  
History Of ◽  
The Antarctic

New discoveries of trigonioid bivalves are documented from three areas in the Antartic Peninsula: the Fossil Bluff Group of Alexander Island, the Latady Formation of the Orville Coast, and the Byers Group of Livingston Island, South Shetland Islands. Eleven taxa are described, representing six genera or subgenera. The faunas are characterized by genera including Vaugonia (Vaugonia), the first Early Jurassic trigonioid recognized on the continent; Vaugonia (V.) and V. (Orthotrigonia?) in the Late Jurassic; and Iotrigonia (Iotrigonia), Myophorella (Scaphogonia), and Pterotrigonia (Pterotrigonia), which span the Jurassic–Cretaceous boundary, reaching the Berriasian stage. The following species are new: Pterotrigonia (P.) cramei n. sp., Pterotrigonia (P.) thomsoni n. sp., Vaugonia (V.) orvillensis n. sp., and V. (Orthotrigonia?) quiltyi n. sp. The faunas show affinities with those of New Zealand and southern Africa. Trigonioids characterize the shallower marine biofacies in the Jurassic of the Antarctic and reflect the principal shallowing events in the history of the region.

V.—The Thickness of the Ice-Cap in the various Glacial Periods

1906 ◽  
Vol 3 (3) ◽  
pp. 120-124 ◽  
Author(s):  
Ernst H. L. Schwarz
Keyword(s):  
South Africa ◽  
Ice Sheets ◽  
Maximum Load ◽  
Earth’S Crust ◽  
Ice Ages ◽  
Ice Cap ◽  
The Alps ◽  
Earth's Crust ◽  
Glacial Periods ◽  
The Antarctic

In estimating the maximum load which pressed upon the northern type of Glacial (Dwyka) Conglomerate in Prieska, Cape Colony, I assumed that the calculations of Sir Wyville Thomson and Bernacci were correct, and that the greatest column of ice that could exist on the earth's surface was from 1,400 to 1,600 feet high. This limit, however, is by no means accepted by European glacialists, who, though they do not go as far as Dr. Croll in assuming thicknesses of 120,000 feet, yet see no reason why there could not have been ice-sheets 5,000 feet thick. The publication of Captain Scott's narrative of the voyage of the “Discovery” has given us certain definite data from the Antarctic which enable the case for the 1,600 feet maximum to be put with more confidence, and I will endeavour in the present paper to state the main lines of the argument. The question is of importance not only to us in South Africa with our two Palæozoic ice-ages, but to all geologists, as it affects the problem of the earth's equilibrium. To give a recent example, Professor Penck, in describing the Bodensee, discusses whether the weight of ice pouring down from the Alps in a sheet 3,600 feet thick may not have had some effect in producing a sinking in the earth's crust.

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