No high Tibetan Plateau until the Neogene.
Sci Adv
; 5(3): eaav2189, 2019 03.
Article
em En
| MEDLINE
| ID: mdl-30854430
ABSTRACT
The Late Paleogene surface height and paleoenvironment for the core area of the Qinghai-Tibetan Plateau (QTP) remain critically unresolved. Here, we report the discovery of the youngest well-preserved fossil palm leaves from Tibet. They were recovered from the Late Paleogene (Chattian), ca. 25.5 ± 0.5 million years, paleolake sediments within the Lunpola Basin (32.033°N, 89.767°E), central QTP at a present elevation of 4655 m. The anatomy of palms renders them intrinsically susceptible to freezing, imposing upper bounds on their latitudinal and altitudinal distribution. Combined with model-determined paleoterrestrial lapse rates, this shows that a high plateau cannot have existed in the core of Tibet in the Paleogene. Instead, a deep paleovalley, whose floor was <2.3 km above mean sea level bounded by (>4 km) high mountain systems, formed a topographically highly varied landscape. This finding challenges prevailing views on tectonic processes, monsoon dynamics, and the evolution of Asian biodiversity.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fósseis
/
Geografia
Tipo de estudo:
Prognostic_studies
País como assunto:
Asia
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article