A model for the formation of carbonatite-phoscorite assemblages based on the compositional variations of mica and apatite from the Palabora Carbonatite Complex, South Africa

Lithos ◽  
2019 ◽  
Vol 324-325 ◽  
pp. 89-104 ◽  
Author(s):  
R. Johannes Giebel ◽  
Michael A.W. Marks ◽  
Christoph D.K. Gauert ◽  
Gregor Markl
2017 ◽  
Vol 102 (6) ◽  
pp. 1218-1233 ◽  
Author(s):  
R. Johannes Giebel ◽  
Christoph D.K. Gauert ◽  
Michael A.W. Marks ◽  
Gelu Costin ◽  
Gregor Markl

Lithos ◽  
2011 ◽  
Vol 127 (1-2) ◽  
pp. 309-322 ◽  
Author(s):  
Fu-Yuan Wu ◽  
Yue-Heng Yang ◽  
Qiu-Li Li ◽  
Roger H. Mitchell ◽  
J. Barry Dawson ◽  
...  

2020 ◽  
Vol 530 ◽  
pp. 115939 ◽  
Author(s):  
Robert Bolhar ◽  
Martin J. Whitehouse ◽  
Lorenzo Milani ◽  
Nivea Magalhães ◽  
Suzanne D. Golding ◽  
...  

2009 ◽  
Vol 4 (6) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Adebola O. Oyedeji ◽  
Anthony J. Afolayan ◽  
Anne Hutchings

Safety of Artemisia afar has been a controversial issue due to its high thujone content. Despite the declaration of the World Health Organization in the 1970s of the plant being unsafe for consumption, it is still commonly used in folklore medication in South Africa, especially in winter. Essential oils were isolated by hydrodistillation from the twigs of A. afra plants from different locations in the Eastern Cape, Free State and KwaZulu-Natal. Analyses of the oils by GC and GCMS revealed compositional variations in the levels of α-and β-thujone, 1,8-cineole and camphor. α-Thujone was the major component of the essential oils of A. afra from Philippolis (Free State) and Keiskammahoek (Eastern Cape) (62-74%), while the camphor content was very low (≤ 0.1-0.6%). The samples from Gqumahshe, Hogsback (Eastern Cape) and Empangeni (KwaZulu Natal) had low α-thujone contents (3.7-20.0%) while 1,8-cineole (13.0-49.5%) and camphor (13.9-21.2%) were the main components of the essential oils. It was further observed that the concentration of α-thujone increased significantly in the dry leaves when compared with the fresh leaves. This implies that fresh leaves are better used for infusion than dry leaves. This study reveals that not all A. afra contain high concentrations of α- and β- thujone.


Sign in / Sign up

Export Citation Format

Share Document