The South Fault is the most interesting location from which samples were collected. This area has two small normal faults where reduced waters rich in Mn and Fe flowed from left to right coming in contact with oxygenated water after fault movement had occurred, causing the Mn and Fe to precipitate out of solution. A previous study by Chan et al., 2001 dated some of the Mn-oxide from this location using the 40Ar/39Ar  system and got ages ranging from 20-25 Ma. We are currently waiting on our (U-Th)/He ages from this fault but if the North Fault is any indication of what is to come we expect the He ages to be much younger than the Ar ages just as they are in the North Fault.

Below you will find a few petrographic images and SEM images acquired from samples from this location along with descriptions.

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14VGCP01-09

Sample 14VGCP01 showing unaltered sandstone with one grain that is completely covered by Fe-oxide (black grain).

SEM image of 14VGCP01. The dark grey grains are quartz, light grey, feldspar, and the white grain is the Fe-oxide. Black "cement" between grains is epoxy.

Sample 14VGCP02 showing a vein made of botryoidal Fe-oxide and Fe-oxide cement between sand grains.

SEM image of 14VGCP02 showing the Fe-oxide as the botryoidal crystals in the vein and transitioning into the Fe-oxide cement between the grains.

Sample 14VGCP03 showing Fe-oxide cement (red, orange) and ground up quartz (white).

SEM image of 14VGCP03 showing the ground up quartz (grey) and areas of Fe-oxide cement (white).

Sample 14VGCP04 showing this odd dendritic kind of finger like shape. The black/silver material is Mn-oxide and the dark red is Fe-oxide.

SEM image of 14VGCP04. Needlelike material is Mn-oxide (center) while the dense material to the right is Fe-oxide. There is no cement between the Mn and Fe.

Sample 14VGCP05 showing spotty Mn-oxide. No Fe-oxide was found in this sample.

SEM image of two different phases of Mn-oxide found in 14VGCP05. EDS shows a difference in Ba and K content between the two phases.

Sample 14VGCP06 showing Fe-oxide (dark red), Mn-oxide (black), and ground up quartz (white).

Mn-oxide cement in 14VGCP06

Fe-oxide in 14VGCP06

Sample 14VGCP07 is the sample with the leopard spots (silver cement with black spots of cement). The black spots are Ba rich Mn-oxide while the silver material is pure Mn-oxide.

SEM image of 14VGCP07. The light grey is the silver pure Mn-oxide in the previous image and the somewhat bright white area is the black Ba rich Mn-oxide from the previous image.

Sample 14VGCP08 showing amazing colliform structures. Silver is pure Mn-oxide, black is Ba rich Mn-oxide, and red is Fe-oxide.

Contact between the Mn-oxide (bottom) and Fe-oxide (top). Bright white spots are made of barite. The contact is easily visible.

Sample 14VGCP09 consists of an unaltered sandstone at first glance.

SEM image of 14VGCP09 where Fe-oxide cement is visible in this area. Fe-oxide can be found in this sample but in very small quantities like shown here.