The Quaternary in the tropics: an introduction

✍ Scribed by J. R. Flenley

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 25 KB
• Volume: 12
• Category: Article
• ISSN: 0267-8179
• DOI: 10.1002/(sici)1099-1417(199709/10)12:5<345::aid-jqs318>3.0.co;2-8

✦ Synopsis

Although the land area between the Tropics of Capricorn

The pollen data from the mountains were still causing and Cancer (ca. 23.5°S and N respectively) represents ca.

trouble. They seemed to demand LGM cooling of 6°-10°C, 25% of the surface of the globe, it has not attracted interest because tropical treelines had apparently been lowered by proportional to that figure in the study of the Quaternary ca. 1600 m in South America and New Guinea. Attempts Era. In some ways this is understandable. There is nothing to square this with a 1°-2°cooling in the lowlands, by in the tropics to compare with the massive till sheets of inventing steeper lapse rates (e.g. Walker and Flenley, 1979), temperate regions. Indeed, the view grew up that climatic were not well received by the climate modellers (Webster changes must have been rather muted in the tropics comand Streten, 1978;Kutzbach and Guetter, 1986). pared with temperate regions. This also is understandable.

The 1990s have brought important advances. Empirical For one thing, the expanded polar ice sheets of glacial pollen evidence has shown that, in many areas, the tropical periods must surely, because of their high albedo, have forests persisted at the LGM, albeit being of a cooler and caused exaggerated cooling near to them. Secondly, the very drier type (e.g.