Cerberus_Fossae_PSP_009913_1910

As this is my first few hours viewing this image from the new HiRISE releases, this may be a rash rush to judgement. I am open to disagreement about this possible fossil crater or vent along the extensive fissure network which makes the Cerberus structure.
I can see a very obvious set of matching items along this circular path at this critical split in the main fissure.
Is this a impact crater, or is this a remnant venting locale?
I'll present additional images in a day.
Thanks, dana johnson
.
A view of the first text link within the shadow details, showing a series of small faults which erode preferentially, and at the merged lanes, a small lighter rounded pattern.
.

.
Marked as a large circular feature possibly, rather than a section of layered undulating flow or faulting. Is this an impact event?
Both of the above are at 1 to 1 of the standard HiRISE full sized imaging resolution.
.

.
A 700% closeup of the structure, which is much less convincing, but which is from the 'cut' JPG HiRISE supplied site source while downloading of the large original file was underway.
In a day I'll post additional images of this feature, and any other co-inciding patterns of hidden content I can find.

Notice in the closeup. a possible additional circular 'vent' or imapt structure at the same level on the fissure.
.

.

As NASA is describing the Cerberus Fossae as a tectonic feature, are these items too old to be a part of the Cerberus structure, and was this a buried simple impact crater. Is it actually a full crater circle, perhaps even an old non-impact vent?
Does the structural integrity reveal that the area was not a dusty plain with a thick mantle of particulate?

Dana; Good to see you are still examining the images for unusual features.
I always look for a simple answer and in this case suggest it is a tension crack where unconsolidated material is falling off the edge into the crevasse.

Thanks, Ben. I had problems with my computer as usual, and still have, took a week to study general interest items, and have moved to a newer browser, side-stepping the issue while cleaning out the cobWebs. Just another Halloween online adventure. Shopping for a pocket computer- sub-$200, for WiFi on the road and shopping- great for gifts for most all.

This image 'jumped of the page' as a patterned event, and I couldn't walk away without sharing it. It is new at HiRISE, and Cerberus is such a very long series of stress faults or fissures within a single historical event sequence, that the signifigance of using this item to date the fissure versus the layered walls seemed worthwhile. I also understand that many haven't the time to look into every shadow for mysteries which would be clearly seen in a differing timing or season. I am still not convinced that this is a crater shape, or an impact related feature.
There are hundreds of viewable tracks of rolling stones across the lowest interior mantle of dark particulate material. That is worth the time of close viewing.
I have at 400-500%, 4-5x, size enlargement, seen now what looks similar to a drainage path across left side of the fissure merging point, just beyond where the full circle would pass, and there appears a substancial fill at the lower point of the shallow 'drainage' channel. Whether liquid was present to cause the path at some time, I couldn't say as yet.
I have prepared a shadow view of the JPG_cut image at 1 to 1 below, to show the transport path. Is this a dry transport, or liquid?
That item is marked in a green arrow.
The lower orange arrow shows how the erosion at a stress fault is eating into the wall. It occurs on the circular feature intersection point, and is obviously related to a circular pattern at that one point.
The yellow arrow shows a steep dipping of the horizontal layers in the shadow where the 'crater' arc is seen. It is to the right of the point at which the circular bright feature is covered by the uppermost layers of the present day dusty surface.
The merging point of the Cerberus fissures at the upper left of center, marks another near intersecting of the circle, and has advanced erosion of the intersection point. That is marked with the red arrow, which also marks a particular fracture of the long axis of the Cerberus Fossae.
The image was solarized to bring out some of the basic information along the fissure paths, and to help show the fissure walls better than a simple washed out white Cerberus plains surface. The black area here is the dust mantle mostly.
.

.
A closeup of the 'drainage path' which may be some type of solid path of debris. I find it compelling in similarity to a liquid path at least part time. The source on the wall would be the bright tubular appearing extension seen just above the path, or perhaps even some point above that. About 400% enlargement, highly altered for shadow details.
.

.
A view of the dusty upper surface, and the circular feature at about 500% size, closeup, but less easily seen at this size.
.

.
A tone mapped, 16 color view, of the color, tone, and textural differences between the now more obvious circular feature.
While this may be very simple appearing, it is more accurate than human vision.
.

.

Has this list of images helped to convince you of the connected pattern of details along the circular path?
Is there a liquid possibility here in the recent timing?
What could cause such a series of co-incidemt details along a circular path, other than a fossil crater?
.

For those who can't, or don't want to download the large imsge file, here is a view of the small JPG_cut file image available on the web, at a reduced resolution and file size.
This may help a few, but all persons should seek the originals for full detail and content.
.

.
This is the original appearance of the larger files from HiRISE, here in JPG.

Dana; The ejecta splatters associated with the impacts in the dusty layer may indicate moisture was involved but I see nothing else that would indicate liquid flow.

I have to agree with you. I am moving very slowly on this image, and I have only just now done a first image on the possible shallow 'trough' or runoff path which was in itself located in a less than likely spot for a 'most noticable' runoff location anyhow. The image below shows what is actually dust layer debris fronts I believe which are fairly thich at the front of the fan as they quiesce from various movements, or one grand collapse movement. Looks to me like multiple debris falls at the near front, with the jutting rock extension as a 'pointer' perhaps even causing some of the multiple dust ripples. I wonder if some of these are wind and not debris fall produced.
At the far right corner and moving to the center are a few very shallow margins of particulate, but not requiring liquids to produce them.
My experience in the deserts, living there for years, would tell me that those could be the result of very short light rainfall, or runoff pass-through, but this is a thick particulate mantle and may not have a solid floor in the canyons here.
The lower right to upper left flatter floor is seen in this heavily altered JP2 original as a long term feature I belive, with the sloping debris edging it in a sharp appearing contact all across.
As I had to severely alter the image in Photoshop Elements to get the shallow shaded ripples and depressions to be accentuated, I'll work on a better image technique and return with that.
I am having some difficulty in bringing the large circular feature adjacent to this area into clear view, and I should have some quality of image Friday to present.
The color balance of this image is from an 'auto-balace dynamic range adjustment from the IAS viewer but needs adjustments. This image is a 1 to 1 view of the details from the color JP2 at the HiRISE site. All prior posts were from the JPEG they published.
.

.
Thanks for the time, Ben, I know it is in small supply these days.
danajohnson

Dana; Thank you for all your effort in preparing the images.
Do you agree that the cliffs are composed of cemented boulder beds which provide the loose boulders in the troughs ??

I negleted to read your question testerday. I did spend some time trying to prepare a few images of the trough bottoms and the shallow details in them, especially the rocks and fallen items at close range.
Those boulders are somewhat rounded or less than hard angles I would call 'shards', and yet most seem to have some angularity and multiple angled breakage evident. Many are seemingly thin on the original horizontal axis, or may have been sheared by the faulting and fractures which are running both lengthwise along the troughs, and at cross angles to the trough long axis.
I'll try to produce a few of the sttep layered sides today. The imaging of both highlight bright sides, and the very dark shadows, in a combined images is still elusive to me as yet. I can't seem to get the shallow features to show in sufficient contrast after bring the highlights and shadows to a close match in brightness. That last image of the floor curved passage through the remaining eroding wall juncture, is the best I can manage as yet(reply 5).
I see several curving fault/fractures crossing the junction of the two troughs, and yet the material of the eroding, rapidly collapsing zone is nearly entirely missing in sections of what should be a continuous debris slope. Something is actively removing large amounts of solid rock and fine particulate material, and the margins of the removed material, is quite steep and complete, although not much removed below the flat trough older floor. The debris slopes are seeming to rest upon a original floor, posibly very much older than the debris from current trough widening.
The troughs both are not very wide, but have a well preserved central lane of finer dark material which is consistently flatter and prone to not have rocks in substancial numbers.
As to the layering, it appears that a great mix of colors, tones, and material makeup is present, and that some layers are rather consistent along a distance, whereas other layers show very defined altered materials along a short distance. The radial or circular aricular? clumped sections are seen in small size even in my 5X, 500%, enlargements I am trying to prepare. A wide range of scale, in that item type is present in the debris, and exposed in layers on the steep walls.
Hopefully some part of the images will show whether this is a single event layering, or a slow seasonal and perhaps 'weather' conditioned accumulation.
It does appear that something has been active along the lower right to upper left angle of the small image I posted, and I know water can cause that to happen if liquid water is a possibility in the past.
I see no real evidence of gully type erosion on these main trough walls.
I do see a very active geology of debris fall, and some method of removal of bulk mass, as in other Cerberus Fossae sections, especially other flat floor bottoms. Speed and timing are older than the debris falling, but rapid enough the keep the dark material at the trough floors only, minus any boulders and medium to large rocks. The troughs are therefore old and from a differing process than the debris falling into them. As these are tectonic or deep fault/fractures, along a very long axis, I wouldn't discount both active gases, and liquids of some mixture, from below, and from frost at the surface. Small quantities would be nearly impossible to track over time, at these scale resolutions.

Dana; I am having difficulty trying to explain how the boulder beds, which look like poorly cemented conglomerate, were formed without a considerable amount of erosion and transport.
Maybe during a wetter Mars there were periods of flash flooding.

These few closeups may help some in seeing several of my points and yours. They are not the best images possible of the location, but they are set with the IAS viewer automated dynamic range adjustment on a setting between 0.03, and 0.001, giving some shadow detail. The images with a color cast were set at a large scale image and not readjusted, the darker and more contrasty images were set closer up, and have a better color balance but less shadow detail.
These are straight from the viewer, but the items beyond 1 to 1 size are enlarged.
I can see in this spot at the termination of one of the fissures, bot a impact of fairly recent geological sequence, a evidence of deep multi-layer effects caused by the impact, a few rounded larger boulder debris items with a predominating angular shard-like varied sized set of broken pieces to a very well consolidated material(possibly multiple material types), and a finer debris set which is more 'soil' like, as a darker fan which appears in some large boulder edges to have slid against the large fixed position boulders, and taken and retained the shape of the contacted sides of the larger boulders, bot angular and rounded.
Does the scene seem a two phase process of actions, more in number, or just a complex scene of one imact causing the various contactual placements?
Here I cannot see water affecting these at the surface at this scale, but I can imagine a scene with a moisture figure aiding in the debris consolidation against the large boulders possibly.
At a distant timing, the area may have been considerably different in appearance, and the fissures, and the deeper layers may be much older than the solid material layers which show the impact(s) with a series of shatter cone shapes, angularity, mixed assemblages, and new overburden layering.
I can see a lack of recent liquids probably.
I can see that the impact scene has allowed for a cliff face to show greater debris and erosion recession from the center of the fissure at the areas not effected by the impacting object.
I can see at the upper impact center, a few shatter cone effects, in addition to the layering being differentially eroded and undercut at layer boundaries.
This is a apparent recent timing to the entire geologic history.
Any water released or produced in the impact would have been much less than a earlier geologic time if climate swings or ATP/STP were greater in the past at the location.
I can see a the debris showing layering appears not solid in mass, but either regolith covered efficiently, or more degraded and soil like.
Appearances are confusing and hidden in photos often. In this HiRISE image this shows many of the characteristics of the overall image locale.
I noticed that in high contrast imaging of the shaded layers, great swings of color and consolidation of the materials seems to be present.
Perhaps a reconstruction of the history is possible from the details. I sure wish we had a few stratigraphy persons to argue the case here.
Degraded solid layers, or sedimentation? Flooding of dense materials or water based floods? Did the impact product the shatter cone shards and the finer layered regolith material. or is there a soil like condition to much of the deeper layers?
.
This is a reference image of the merged area of the two fissures. It contains the circular feature on the left side shaded wall, the upper surface impact cluster near the center of the circle I had marked in earlier posts, and the all the subsequent images in this post are from an area just to the right along the lower section of this image just out of range. The impact cluster here looks to be somewhat older than the subsequent images single impact, about which I am writing in this post.
The image here, I belive is set at DR of 0.03, sharpened to 2.44.
.

.
This image is at 1 to 2 size, of the termination of the fissure which extends to the lower right in the image above. As I had to rotate these images to obtain the longest axis sought as horizontal on my screen, you are seeing the non-corrected images at various angles. Hopefully you can rework these orientations in your mind as I show them, referring to the full image JPG thumbnail.
The impact here look to me to be recent, the wind drift of smaller ripple of dust are carried consistently to the left only within the range of the fissure, and no dust rippling is seen beyond the extent of the fissure. The wind is to the left, but if you look at the closeups below, the fissure floor shows wind tails opposing and varied to that.
.

.

.

.

Dana; I still can't see the impact features you refer to and have tentatively concluded that the troughs are "grabens" that have resulted from collapse. This is confirmed by no evidence anywhere for the material that would have been removed from the troughs.
The layered material visible in the walls is most likely flood basalt composed of bouldery flows which have been broken up by long periods of small impacts.

I certainly can't argue that the view shows necessary ponding to fill the current troughs, but my point was that the recent impacted item has secured a tougher set of layers below the crater(s), and that subsequently the less altered material around the subsurface shock cone altered material has weathered away by whatever weathering is present, and was present during the post impact periods.
If the trough walls are actively receeding into the plains away from the center axis lines of the Cerberus Fossae's many fissures, and as these are a network of linear features as a large scale event, the geology here is active recently more than in Mars early history. In fact, the fissures may be periodically active during unknown periods of Mars deep geology activity, or suseptable to climatic changes in large scale.
I find it challenging to axplain how recent impacts can alter the trough wall by adding to the linear cliff face which is nearly straight except in the only areas of direct impact activity. The statistics, as in many other unusual subjects of Mars smaller features, is just not a happin-stance co-incidence, but rather a cause and effect process of erosion activity where protection is caused by recent events. If the troughs are now active in recent geological timing, this may show a connectedness with other regions of subsidence which appear to be recent.
I'll mark a few of the items I described and post new images. I have altered the closeups above, to make the items more 'realistic' in appearance for yourself and others. I can tolerate some very distaorted images when doing my study. Others are alienated by the off color and poor image qualities at times.
These were altered by 'auto' settings in XNView, and are about as good as I can do in single layer images.
.
This seven tone/color mapping of the large scale features shows that the two intersecting cliff face points which are red in debris coloration, are nearly correct to my marked circular structure. The right side extension of the terminal fissure is very different in particulate color and tonality. There is a slight depressed passage across the dusty surface to the cliff face just below the newest impact crater, but the dust colored material is masked comepletely by the darker debris overburden. I assume more than one impact is recorded in the rocky debris even at the fissure termination. Collapse may have been inherent or impact caused possibly. Does that sound reasonable to leave the cause open?
If the fissure is widening by responses to recent impact activity, and the larger impact shock cones are causing the fissure shapes to be moderated, as perhaps is occuring at the merged section of the two fissures, can the troughs be reasonable young in timing/ Did the widening actually happen along the fissure termination after the impact I show in the closeups?
Did the fissures recntly accelerate in widening? I can see the darker older trough bottom as very old, but here I am shoing a cliff wall protected from erosion by a fairly recent impact event. Perhaps.
.

.
Images below:
Color was hand saturated about four points, all else is auto adjusted in a photo editor.
.

.

.

.
Certainly chance hasn't arranged a series of closely associated actions which currently appear to give a timeline of fairly recent for a structure like this trough termination as widening along here.
With the large debris I have marked in red arrows for you showing the debris fan causing the attachment of the 'crust' and molded shape giving a timing of the larger rocks setting at the upper surface of the trough floor as prior to the finer debris fan, and the core of the trough being no wider than the inner face of the impacted layered extension which was itself almost certainly produced in the impact causing the finer debris fan, how can a large percentage of the trough be formed after the recent impact event? Where is the cause for recent geological action in the area?
Certainly the impact did not widen the trough cliff face at the one point where the impact occured.
I can reason the plaqued crust and molded attachment on the rocks being cleaned and removed by the wind and radiative stresses, and the temperature swings over recent time.
If the walls of the trough have recessed by the amount of the dark extension at the impact spot, all along the trough, where is the debris, and what is it now? Were these troughs rather deep?
How could an event possibly add to the measure of the trough wall at this one point only?
Does this mean the tectonic processes are actively forcing the upper Mars crust to fail and susbside in large scale?

My apologies for any typos, as spell-check isn't set up on this copy of Opera browser as yet.

Dana; My interpretation of these canoe shaped troughs is that they represent collapse of a magma chamber beneath the surface. THis was caused by the removal of basalt which has been extruded and formed the layers visible in the cliffs.
I really don't think impact had anything to do with them...

The troughs don't appear to have been widened much and the talus slopes are the only material filling them.
Collapse was probably rather sudden and is not related to tectonic activity .

Ithink it ultimately be shown that most of the steep sided troughs on Mars are related to an early period of basaltic eruptions and flows followed by collapse of the subsurface lava channels.

Seeing the vast remnant collection of production and flow areas which are still visible nearly everywhere on Mars, I was formerly inclined to agree comrpletely. Except, that the activity was so vast and dominating that the water must have had a substancial transient surficial effect periodically, even if only frost or snow, or ground ice layered into the structure.
Reading acounts of Mars mantle in phase shifting resembling the surface of a water body, rising as the ice swells was a real excitement to me when younger. Knowing the powering of massive volcanism could be pressure related made me think about the temperature and pressure at which the freeing of the gases would happen. A colder Mars, and a colder mantle at similar timing.
Regardless of the causes of the body forming the Cerberus plains, the single linear feature making the Cerberus Fossae is a real and very large event process.
T think of the rapidness of the walls receeding if they did, or to relate the recent appearance of the impact at that one point which is apparently responsible for the protection of the cliff wall just at that one point, tells me that the changes are more effective now than in the past.
It may be the events are not timed correctly by myself.
I also have thought of periodic frost or other corrosive materials altering the local floor to hide the debris infalling.
I admit it does look to be a former basalt floor well degraded and yet you can see there is no similarity between the floor materials of aged timing, and the plains upper dust covered surface. The dust is being heavily altered or 'disappeared' by a mechanism, and that is similar to many other areas of Mars.
I look under the cliff face ledge and marvel at the near complete lack of stacked, aged debris. There is a clearing event underway, or the material has never infallen to the current floor level.
A deeper functional floor, with a mantle of altered dust and soil type regolith?
A removal/alteration process which is not seen?
Here is two unrelated photos which I am working with in regard to the 'shock cone effect of the impacts that seem to be altering the erosion potential of layered materials on Mars.
This area is closer to the polar ice layers, and the scene is a layered downhill slope from right to left in the images.
There is marked along the center of the images a channel cut into the layers which is masked by the noise of the 'swiss cheese' appearing terrain. Many such channels are being cut into the terrain, but this carries the logic and a long passage downslope into a large pit structure. The source is the wind tail of a large mounded cone, apparently a shock cone of a now eroded crater. In the passage of time the channel has been eroded with or without actual liguid flow. It none-the-less carries the impression of a riverbed, and would function as such in warmer times with a denser atmosphere.
This is an example of the difficulty I have in determining whether liquids played some part in the erosion, or the cause of the channel.
It really all depends upon the climate, and the level of local geology actvity.
Tomorrow I'll post a larger scale reference image of this polar scene, to clear any mis-direction I may have introduced to the conversation.
.

.

.
No time for a spell check again.

The images above are PSP_009855_2625.

The HiRISE main page for the Northern Polar Layered Deposits image I had marked in the prior entry #13.
The image was related to the Cerberus trough image in regard to the 'shock cone' impact effect producing stabilized areas resistant to erosion, and in offering a potential for seeking some ancient evidence of liquid flows across the downhill slopes of landmarks such as these two unusual Mars features.
I can't see any convincing proof of liquids at these sites, but the amount of overburden and alteration of the surface may mask any prior evidence.
In the polar cone and pit, the channel type shapes are explained partly by the ice/dust layers producing both sedimentation and removal in many cycles, and erosion type combination actions have given preference to the downhill paths leading from the conical mound in a meandering path to the lower elevation darker pit deposits. Liquids in either may have flowed at times under the viewable surface levels.
Layer margins of former ice appears to have formerly covered the cone height to the top, indicating a scene of ice depth tens of feet above the current surface. The timing isn't clear, but the removal of material has left a record. Exposed in the complex record, is removed ice and possibly removed dirt or dust tens of feet deep.
The channels I was viewing as nearly continuous over a distance, with the greatest erosion effect, are traveling downhill into the darker pit. Can the co-incidence here again be another Mars statistical oddity? Why again is the icy terrain is the lowest level dark and smooth, with unique textures and tonality/coloration from the surrounding domain?
A overview in grayscale of the conical mound with the darker pit downhill. The waypoints I had seleted to show the smoother channel path are visible. Several of these channels while not depressions all along the path currently, are extensively complete from the slope near the cone base, to the dark pit.
.

.
Even the small JPG's on the HiRISE page show the channels have two walls and are eroded more than the hundreds of adjacent criss-crossing ice layer former margins. A preference for erosion at gravity controlled paths which are continuous and consistent in width and depth.
Possibly this polar example of channel formation selectivity is not a 'shock cone' with a downhill pit depression scene, but some variety of erupted material?
.

.
Marked paths of former ice layer margins which are now partly channels and in areas positive raised relief deposits. These are now two walled.

I'll return to Cerberus Fossae in the next entry. I wanted the erosion related to a shock cone landmark to be a subject within my observations of the Cerberus troughs. Differential erosion in both main imaged areas is appearing out of timing, and downhill passage from the shocked spots show the appearance of liquid or ice erosion over great time. The areas marginal to a probable shock cone show preferenced erosion rates also, as a possibility.

Dana; Since we don't have similar ice/dust layers on earth , I frankly don't have any ideas about the processes involved.

I see some details in the photo of the far north cone and pit in the layered terrain, and I'll present the list in a proper separate topic. I believe the details worthy of public exposure, and the suggestion of the closeups is of thick flow and patterned movement. As the cone and pit are more aged than the upper ice layers, these are a signal of local geology processes with much potential water present.
The Cerberus Fossae alternatively, while described as a possible flood plains carying episodic water flooding, show little surface flow detail. and finding evidence of water flow if it occured around and within the parallel fissure network, seems contradicted by the depressed trough fissure floors, which could have served as a repository of sediment and liquid erosion processes had the flooding occured after the fissures opened. My interest in the two compared, is for details such as this image of the near polar erosion trough passing around the 'ghost' crater terrain item marked below. The troughs which show active geology are detoured around the crater rim within the ejecta zone in the ice layered terrain, in frozen tundra at or below perrenial freezing temperatures.
Craters form a resistant material eluding breakdown along the margins at both the apparent dry fissures of Cerberus(PSP_009913_1910), and the icey and potentially 'wet' far north(PSP_009855_2625).
Each were described as either a flood plain, or a layered seasonal ice capped terrian. The descriptions from NASA associated groups accomodate waters presence, and removal. Both show erosion forming troughs with apparent resistent crater margins.
.

.
The final image of the seasonal ice layered area here, will match one on a topic for the is HiRISE image, as the processes which are complexly detailed and cryptic show erosion, deposition, movement, trough-like formations to downslope destinations, and yet may consist of erosion/sublimation/alteration processes mimicking the processes of liquid water. Large volumes of semi-liquid material flowed across the scene in PSP_009855_2625, and layers of water ice/CO2 ice have dominated the scene with an overburden which was seasonal, but the actual quantities of liquids involved, and the timing of the production of the flows is masked by recent surface events. Buried or ghosted craters, and possible shock cone central peaks mak be actively guiding the trough erosion paths. Volcanic type flows or some variety of semi-liquid mud/ice are forming downslope patterns which also guide the erosion of the troughs. The lowest elevation depressions show both positive and negative space relief in apparent material movement. Large volumes of material has been removed from sections of the trough/rill passages, and the material was effectively extracted from the direct environment of the passages by some processes.

The Cerberus materials also were removed from the troughs, or the troughs were enlarged to allow subsidence, and erosion processes show a preferred rate at areas marginal to crater rims.

The activity of the erosion/alteration of material in the zones protected from the direct atmospheric wind passage seems to be present, possibly in both photo closeups. The wind tail of the north polar large scale photo shows the very precise occurance of the symmetric slumping of a large volume of the conical mound. The activity and energy/chemistry to effect that would have been substancial, and was limited in a clear viewable pattern. The slumping was not controlled by the quantity of sunlight exclusively, and the pattern symmetry of the slumping shows differential direct sunlight radiation is ineffective in conditioning the erosional activity by degree, and generally.

Erosion on Mars is active in wind tails preferentially in the PSP_009855_2625 polar zone. There is some small evidence of that effect in the Cerberus image as well, I believe. We see the effect as a wind deposition process normally, in casual thinking. The casual thought is not correct.
Alteration or removal is active.

In my post above at #17 I stated the slumped cone side was placed between the wind tail margins. It is actually placed between the sunlighted margins perpendicular to the strongest sun angle, where the sun is most elevated at noon. That places the sun heating as the most probable cause of the slumping action.
I spend most of each away from these images, and posted my recollection in haste, switching the sunlight angles to the wind tail streak markings. The slumping has occured only within the wind tail, and not outside the margins of the wind tail. The slump is confined both within and centered on the sunlight average maximum angle, and is well centered within one wind tail vortex along the side of the wind tail. The area of the slump also co-incides with the lowest elevated section of the cone base, centered perpendicular to the downslope maximum.
I should have carefully assessed my recall before posting the statement.
The images have so much detail in small features that I am having difficulty in making enhancements of image at large scale.
The terrain takes some re-oriented thinking, and even then is confusing.
The relative importance of sunlight, wind, and slope are all open questions for me again in the ice layered terrain.