Recent pollution records in Sidi Moussa coastal lagoon (western Morocco) inferred from sediment radiometric dating

2021 ◽  
Vol 227 ◽  
pp. 106464
Author(s):  
A. Benmhammed ◽  
A. Laissaoui ◽  
N. Mejjad ◽  
N. Ziad ◽  
E. Chakir ◽  
...  
2008 ◽  
Vol 104 (11/12) ◽  
Author(s):  
J.C. Vogel ◽  
M.A. Geyh

The radiometric dating of calcrete is often problematical because impurities and open system conditions affect the apparent ages obtained. By applying both radiocarbon and uranium-series dating to calcrete in colluvium, it is shown that such conditions can be identified. In correlation with the stratigraphy, it is found that partial recrystallization severely decreases the radiocarbon ages of the upslope and shallower samples further down, whereas incorporation of limestone fragments from bedrock significantly increases the apparent ages of some of the uranium-series samples. It is concluded that the hillslope calcrete at the study site near Sede Beker in the Negev Desert, Israel, mainly developed shortly after 40 kyr ago, at a time when the Jordan Valley was being inundated to form the fossil Lake Lisan. Since their formation would have required higher rainfall than today, the results provide further evidence that the whole region was experiencing an increase in precipitation.


2009 ◽  
Vol 8 (6) ◽  
pp. 1377-1383 ◽  
Author(s):  
Mohamed Chiban ◽  
Gabriela Lehutu ◽  
Fouad Sinan ◽  
Gabriela Carja
Keyword(s):  

2010 ◽  
Vol 20 (7) ◽  
pp. 751-762 ◽  
Author(s):  
Abderrahim El Keroumi ◽  
Khalid Naamani ◽  
Abdallah Dahbi ◽  
Isabel Luque ◽  
Ana Carvajal ◽  
...  

2021 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Maria Ceraulo ◽  
María Paz Sal Moyano ◽  
Fernando Jose Hidalgo ◽  
María Cielo Bazterrica ◽  
Salvatore Mazzola ◽  
...  

Human-generated underwater noise and its effect on marine biota is recognized as an important issue. Boat noise can affect the communication success of fish species that use sounds for spawning purposes. During the reproductive period, males of the black drum Pogonias spp. produce calls ranging from 90 Hz to 300 Hz. In the Mar Chiquita coastal lagoon (Buenos Aires, Argentina), Pogonias courbina is one of the primary fishing species. Although no regulation is directly applied to protect it, a ban protects the reproductive period of other fish species during weekdays. Here, we investigated the potential effect of boat noise on P. courbina vocalizations through a passive acoustic method. Acoustic data were collected, and P. courbina calls were identified and counted. The files with boat noise passages were categorized into classes according to their noise frequency range (A = below 700 Hz, B = over 700 Hz, and C = below and above 700 Hz). The fish call rate was lower in files where boat noise overlapped the fish call frequency (Classes A and C). Only boat noise from Class C was significantly reduced during days with the active fishing ban. These results suggest that anthropogenic noise may affect the P. courbina call rate and underline the importance of including the evaluation of anthropogenic noise in the current management of the area.


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