Oban hill
 
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Oban hill |
The Oban Hills are a hilly landscape in southeastern Nigeria . The hills extend to the southwest of Cameroon .
Since November 1, 1995, the Oban Hills have been on the UNESCO World Heritage List .
geography
The Cross River National Park in southeast Nigeria is divided into two non-contiguous sections.
The northern part of Bosh / Okwongwo with approx. 1000 km² is ecologically connected to the Takamanda National Park in Cameroon.
The Oban Division with its hills belongs to the southern part of the park. With around 3000 km², this part of the park represents the greater part of the Cross River National Park. Similar to Bosh / Okwongwo, the Oban hills extend over binational territory. On the Cameroon side, they are part of the Korup National Park .
geology
As early as 1901, an article on the geology of the Orban Hills was published by a certain John Parkinson, BA, FGS in the Quarterly Journal of the Geological Society . He came to the conclusions:
- The Orban Hills consist of extensive stretches of crystalline rock. In the former British territory there are also chalk formations and sedimentary rocks .
- The crystalline rock is divided into two groups. They are available either with a layer structure ( foliation ) or without.
- The first consist of acidic orthogneiss , which have a tendency to transform the layer structure into granite.
A potassium-argon dating from 1999 with metamorphic rock from the Oban Massif showed the following age:
- Amphibolite 592 to 930 Ma
- Layer gneiss 492 to 538 Ma
- Granodiorite gneiss 502 Ma
- Slate 514 to 519 Ma
- Charnockite 481 Ma
While earlier rubidium-strontium dates or lead-lead dates came to the conclusion that the layer gneiss originated in the Neoproterozoic period, today it is dated to the time of the Cadomian orogeny .
biodiversity
flora
At least 1568 different plants can be found in the hills of Oban. 77 of the plants are endemic . The plants include epiphytic ferns as well as numerous orchids . Trees that can be found in Oban include a. Afzelia ( camwood ), ebony trees and mahogany trees . Other trees that typically occur are Berlinia confusa from the carob family , Coula edulis from the Olacaceae family , Hannoa klaineana from the bitter ash family , Klainedoxa gabonensis from the Irvingiaceae family , Khaya ivorensis from the Khaya family and Lophira alata from the family the bone-leaf family .
fauna
At least 75 species of animals have been discovered in the area. These include forest elephants ( Loxodonta cyclotis ), chimpanzees , drills , Prussian colobus monkeys and African buffalo .
At least 282 birds have been inventoried. In a biological report from 2003, on the hills of Aking and Ndebiji u. a. the Olivenibis ( Bostrychia olivacea ) which Rotfußralle ( Himantornis haematopus ), the Austernfischer ( Haematopus ostralegus ), the crown Adler ( Stephanoaetus coronatus ) which Prachtkauz ( Glaucidium sjostedti ) and the Olivkuckuck ( Cercococcyx olivinus ) seen.
In addition, 42 species of snakes were discovered.
environment
As in almost the entire African rainforest, poaching is a massive problem in the Oban Division. Göttingen scientists are therefore trying to minimize poaching in a funded project without neglecting the interests of the population. Similar research was carried out in Nigeria in 2008, when the area of tension between sustainable income and preservation of the environment as part of the wildlife trade was examined.
literature
- Chris O. Oke: A new species of Streptaxidae (Mollusca: Gastropoda: Pulmonata) from southeastern Nigeria. In: African Zoology. Volume 42, Issue 2, October 2007, pp. 286-288.
- AB Rendle: Catalog of the plants collected by Mr. & Mrs. PA Talbot in the Oban district, South Nigeria. Trustees of the British Museum, 1913.
- John Parkinson, BA, FGS: The Geology of the Oban Hills (Southern Nigeria). In: Quarterly Journal of the Geological Society. 1907 63, pp. 313-316.
- Barth N. Ekwueme, Tetsumaru Taya, Hisatomo Yabe: K-Ar ages of some metamorphic rocks of Oban massif and their implications for the tectonothermal evolution of Southeastern Nigeria. In: Journal of Mineralogy, Petrology and Economic Geology. 2000, Vol.95, NO.2, pp. 58-68,
- EA Eniang, ME Eniang, CE Akpan: Ethiopian Journal of Environmental Studies and Management. Vol. 1 (1), 2008, pp. 70-83.
Individual evidence
- ↑ http://whc.unesco.org/en/tentativelists/493/
- ↑ http://www.dib.boku.ac.at/fileadmin/_/H83/H832/Masterseminar/Ojobor_SemAbstract07.pdf ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ http://www.123independenceday.com/nigeria/heritage.html
- ↑ http://jgslegacy.lyellcollection.org/cgi/content/abstract/63/1-4/313
- ↑ a b Barth N. EKWUEME, Tetsumaru ITAYA, Hisatomo YABE: K-Ar ages of some metamorphic rocks of Oban massif and their implications for the tectonothermal evolution of Southeastern Nigeria. In: Chemical & Pharmaceutical Bulletin . , vol. 50 (2002), no. 7, pp. 1007-1010; doi : 10.2465 / ganko.95.58 .
- ↑ http://www.nigeriaparkservice.org/crossriver/Default.aspx
- ↑ http://ia341028.us.archive.org/1/items/catalogueofplant00brituoft/catalogueofplant00brituoft.pdf
- ↑ BirdLife IBA Factsheet Cross River National Park: Oban Division (Eng.)
- ↑ Archived copy ( Memento of the original from September 5, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ http://www.nigeriaparkservice.org/crossriver/Default.aspx
- ↑ http://www.goettinger-tageblatt.de/newsroom/wissen/dezentral/wissenlokal/art4263,663584 ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ http://www.uni-goettingen.de/de/3240.html?cid=3041
- ↑ http://www.ajol.info/viewarticle.php?id=42777
Coordinates: 5 ° 30 ′ 0 ″ N , 8 ° 35 ′ 0 ″ E