Distribution Patterns of Catenae
                           (Pit Crater Chains)   

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Martian Landforms Distribution  Patterns
Cochise College- Mars Landforms

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Roger Weller, geology instructor ( wellerr@cochise.edu  )
last edited:  6/5/15    


types of features in this study
 
 
 
Catenae or pit crater chains are characterized by a series of craters with
    no discernible rims that lie along a linear path.  In most cases the craters
    are created by surface drainage into large sub-surface fissures.  Another
    mechanism for the creation pit crater chains is partial collapse of lava
    tubes.

    The plural of catena is catenae (Latin word).

examples
 
 
 Craters lie along the bottom of a graben.
  


    Some of the pit crater chains are probaly partially collapsed lava tubes.
   

    The pit crater chains occur in an en echelon pattern.
   

    inclined view- Valles Marineris area
     

Click here for a larger collection of photos: catenae


planetary distribution patterns of catena features
(Wide white lines are pit crater chains.)
 
 Mars centered at 100 degrees West longitude
area of maximum number of pit crater chains



180 degrees away- no pit crater chains
(white area is a lack of photographic coverage)


Contrast shown in diagram format

Maximum at 100 degrees West longitude





Minimum at 80 degree East longitude (nothing)
 


Closer look at areas of highest concentration

#1- Catenae radial to the Tharsis bulge



#2- Parallel to Valles Marineris



#3- Along the periphery of a large shield volcano (mons)

Arsia Mons
view- 560 kilometers across


Ascraeus Mons
width of view-810 kilometers


discussion

  
The largest number of pit crater chains are closely tied into graben
structures.  Most graben features within the area North of the Tharsis
bulge do not have pit crater chains.  Of the few that do, the graben
features are arranged in an echelon pattern.  En echelon fractures are
tension features created by some shear below the surface.  The tension
fractures must be large and deep in order to allow such large quantities
of surface materials to drain away.