Abstract Title: Speculations on the evolution of the East California Shear Zone 
and associated structures by fault propagation: comparison with the mechanics 
of Anatolia and the Aegean.

Abstract Author(s): King, Geoffrey, IPG Paris, France - Friedrich, Anke, 
Institut fźr Geowissenschaften UniversitŠt Potsdam, Germany - Bowman, David, 
Department of Geological Sciences, California State University, Fullerton, CA.  
 

Abstract: Studies of the North Anatolian Fault System (NAFS) in Turkey and 
Greece have shown that it has evolved by slow growth (propagation) over 
millions of years. The system initiated about 13 Myrs ago in eastern Turkey as 
a result of the collision of Arabia with Asia. After crossing north Anatolia it 
reached the Marmara Sea in western Turkey 5 Myrs ago before extending into the 
Aegean. Prior to the arrival of the NAFS the Aegean had experienced slow 
extension for more than 15 Myrs. The compressional deformation field associated 
with the NAFS on its southeastern side suppressed Aegean extension to the 
southeast of the fault. To the northwest increased extension rates resulted in 
the rapid opening of the North Aegean Trough and the Gulf of Corinth over the 
last 1Ma. A similar sequence of events can be proposed for the western USA. By 
about 5 Ma the southern San Andreas had jumped inland allowing the Gulf of 
California to open, creating the big bend and uplifting the Transverse Ranges. 
At about this time the Garlock fault propagated to the east reaching the 
present Owens, Panamint and Death (OPD) Valleys about 3 Ma. Prior to the 
arrival of the Garlock fault the Basin and Range had been subject to extension 
for about 20Ma. The processes of propagation suppressed extension south of the 
Garlock fault east of the present Mojave, and enhanced activity in the OPD 
valleys. This extension was associated with the onset of volcanic activity and 
as the extension propagated to the north volcanism appeared in the Mammoth 
lakes region about 1-2 Ma. Except for the extensive volcanism, the evolution is 
very similar to that observed in the Aegean. However the OPD faults and their 
associated mantle structures once formed became activated in shear associated 
with the American-Pacific Plate boundary at about 1 Ma. A new episode of 
propagation ensued with shear deformation extending south into the Mojave block 
and north to rejuvenate or enhance extension in the Carson Sink Dixie Valley 
region.