Weller, geology instructor (
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
The plural of catena is catenae (Latin word).
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)
view- 560 kilometers across
width of view-810 kilometers
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.