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Migration of the Intertropical Convergence Zone in North Africa during the Holocene: Evidence from variations in quartz grain roundness in the lower Nile valley, Egypt

Autor
Marks, Leszek
Liu, Yan
Zhao, Xiaoshuang
Chen, Jing
Chen, Zhongyuan
Sun, Qianli
Jiang, Jun
Salem, Alaa
Welc, Fabian
Data publikacji
2017
Abstrakt (EN)

This study reports the high-resolution (50–100 yr) temporal variations of quartz roundness used as a climate proxy in the sediment core FA-1 recovered in the Faiyum Basin of the lower Nile. A higher proportion of transparent angular quartz can be found in sediment transported from the upper to the lower Nile via runoff when the Intertropical Convergence Zone (ITCZ) migrated northwards during the Holocene. The stained rounded quartz in the core sediment can be linked to windblown input into the Faiyum Basin from the Sahara Desert when the ITCZ shifted southwards. Using this theory, we reconstructed the series of Holocene climate changes in relation to the ITCZ migration. Our quartz evidence revealed: 1) the African Humid Period (AHP) occurring in the basin at 9200–4200 cal. yrs BP; 2) a short-term (5800–5400 cal. yrs BP) aridification occurred during the AHP; and 3) the rapid onset of hyper-aridification at ca. 4200–4000 years ago, which then persisted. These ITCZ related climate pulses, have basin-wide implications supporting relevant paleoclimate studies in North Africa. In addition, our results suggested at least 3 times when hydro-geoengineering works were implemented to source water from the Nile for local farming during the hyper-aridification period.

Słowa kluczowe EN
Quartz roundness
TCZ
Holocene
Climate change
Hyper-aridification Nile River
Dyscyplina PBN
nauki o Ziemi i środowisku
Czasopismo
Quaternary International
Tom
449
Strony od-do
22-28
ISSN
1040-6182
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