Dear Colleagues,

The next Colloquium of African Geology (CAG) will be organized in Addis
Ababa, Ethiopia from 8 to 14 January 2013. 
Outstanding field excursions (3 pre-conference, 3 mid-conference and 4
post-conference) to various parts of Ethiopia will be organized. 

See www.CAG24.org.et

The deadline for submitting abstracts has been extended to September 15th.
The important dates are now: 
Sept. 15, 2012: Abstract submission deadline; 
Sept. 30, 2012: Online Registration deadline; Decision on abstracts and
fellowship requests communicated to applicants; 
December 1, 2012: Deadline for payment of fees by bank transfer and Deadline
for money refund.

There will be a session on craton formation and destruction (Session 1.1)
and a session on the nature and significance of the Pan-African Orogeny
(Session 1.2). Perhaps you are interested to contribute! See description
below.

Session 1.1. Craton Formation and Destruction
Conveners: Alfred Kröner, Jean-Paul Liégeois, Axel Hofmann, Abder Bendaoud
The formation of cratons and their possible destruction is one of the most
important events in the history of continental evolution, yet we neither
fully understand the mechanisms of craton formation nor the cause and
mechanism of craton destabilization and destruction. This multidisciplinary
session is aimed at an exchange of ideas on a wide range of topics related
to the formation and evolution of cratons in Africa and other
Gondwana-derived continents and their relationship to tectonics,
metamorphism, and mantle dynamics. The Kaapvaal craton of southern Africa is
considered one of the oldest and most stable cratons, whereas the eastern
part of the Tanzania may have been destroyed and reworked during the
Pan-African orogeny, and the Sahara metacraton may be an example for partial
craton destruction. Is the evolution of the North China craton a general
model for craton destabilization?

Session 1.2. Nature and Significance of the Pan-African Orogeny
Conveners: Jean-Paul Liégeois, Asfawossen Asrat, Mohamed G. Abdelsalam,
Aberra Mogessie, Robert J. Stern
The Pan-African orogeny of Neoproterozoic and Early Paleozoic age shaped the
African continent and a large part of the world because it is globally
linked to the continental convergence that generated the Gondwana
Supercontinent. Consequently, the expression "Pan-African" is also widely
used outside Africa (in addition to Brasiliano, Cadomian, Vendian, etc).
However, the term Pan-African orogeny is used by different authors in a wide
number of ways, including referring to: (1) all Neoproterozoic (1000-542 Ma)
orogenic events, (2) Ediacaran collisional and post-collisional events
(630-570 Ma), (3) Ediacaran-Cambrian orogenic events (635-488 Ma).
Consequently, nowadays, Precambrian geology researchers do not restrict the
use of the term Pan-African orogeny to the original definition of Kennedy
(1964), a ~500 Ma thermo-tectonic event based on K-Ar ages, which now must
be regarded as cooling ages. These variations arise from the fundamental
loose definition of an orogeny (that can include the early oceanic accretion
phases preceding the main collisional phase) combined with the diachronic
character of such a large orogenic event. We think it is time to redefine
the term Pan-African orogeny, ~50 years after Kennedy’s original but
obsolete definition. Refining the term Pan-African orogeny requires
understanding its nature and significance within the entire African
continent and in other continents that were part of the Gondwana
Supercontinent. This requires a nested approach of acquiring
multidisciplinary geoscientific records from continent-wide scale to
detailed studies. The Colloquium of African Geology is a well-suited
platform to advance our knowledge of the Pan-African orogeny through
original presentations and share ideas on future research. All original as
well as review contributions dealing with the Neoproterozoic are thus
welcomed, provided a final conclusion is given concerning the definition of
the Pan-African orogeny.


Wishing to see you all in Addis in January 2013!

Cheers,

Jean-Paul 

Jean-Paul Liégeois
Head of Division
Isotope Geology
Royal Museum for Central Africa
B-3080 Tervuren Belgium
Tel/Fax: + 32 2 650 2252
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http://www.africamuseum.be/museum/home/contact/staff/LIEGEOIS_Jean-Paul