• Библ. индекс 18671
  • Тип материала: S
  • Автор(ы): Poulianos N., Koutavas A.
  • Редактор(ы): 
  • Год: 2009
  • Название: COMBINED NEW PALEOCLIMATOLOGIC AND CHRONOLOGIC EVIDENCE FROM PETRALONA CAVE
  • Источник: 15th International Congress of Speleology
  • Место публикации: USA
  • Том: 
  • Выпуск: 
  • Страницы: 121-121
  • Web/Url: 
  • № полки: 
  • Добавлено: Elmaz
  • Ключевые слова: PALEOCLIMATOLOGIC, CHRONOLOGIC EVIDENCE, PETRALONA CAVE, Греция, палеоклимат, датирование, изотопы кислорода,
  • Источник: 
  • Реферат:
    The Petralona cave in northern Greece was discovered 50 years ago, in May of 1959. The paleoclimatologic and chronologic study of the cave sediments and findings has been advanced over the past half century through many scientific publications, often quite controversial. Initial age estimates of ~50,000 years were in 1968 corrected (by 1000% or more) toward much older dates. Currently, the debate is internationally oriented around two main axes. One indicates ages of about 0.3–0.5 Ma while the other 0.6–0.8 Ma. Taking into consideration previous data and the importance of paleoclimatic evidence for the understanding of present-day climatic and environmental conditions, this paper presents preliminary new results of relevance to the issue. The results are based on new U/Th dating and oxygen isotopic analyses of three surface stalagmitic samples (from the 1st layer of the Petralona stratigraphic series). The sample ages range from 235 to 500 thousand years ago (ka) and indicate significant differences in growth rates likely corresponding to different hydrologic and climatic conditions. Highest growth rates (approximately 3 cm/ka) are observed in two samples that grew between 235–246 ka, and 416–420 ka, most likely corresponding to warm interglacial stages 7 and 11. An oxygen isotopic shift of 3 per mil in the latter sample is consistent with the climatic transition over termination IV (stage 11–12 transition). The results support earlier evidence for major climatic changes in the region, that emerged through the stratigraphic studies and excavating activities of the Anthropological Association of Greece. Further details of the paleoenvironmental evolution and the oscillations of warm and cold periods from Petralona speleothems are in progress for the future.