Mapping the layered geology of Mars
Click for original image.
Today’s cool image is an update of a previous cool image from July 2021. Then, I posted a captioned high resolution Mars Reconnaissance Orbiter (MRO) photo of the many terraced layers within a 13-mile-wide crater dubbed Jiji and located in Arabia Terra, the largest transition zone between the Red Planet’s northern lowland plains and the southern cratered highlands. At that time the caption noted that research was on-going to see if the same layers could be identified in two other nearby craters, Banes and Sera, and thus use that data to extrapolate the long term geological history of this region on Mars.
Today’s cool image to the right, rotated, cropped, reduced, and enhanced to post here, was taken on January 4, 2024 as part of this research, and shows the layers in 18-mile-wide Sera crater, located only about ten miles to the east of Jiji crater. The highest mesa near the bottom of the picture is about twenty feet high on its southern side, but about 140 feet high to the north. The difference is because the crater floor under the mesa is sloping downward to its lowest point to the north.
Figure 13 from paper. Click for original graphic.
The white dot on the overview map to the right marks the location of Sera crater, with the rectangle in the inset showing the area covered by the picture. The dark areas inside Sera of dust covered dune fields.
According to a paper published in March 2023, the geology of the layers in these two craters is linked, and appear to be also linked to the geological history of the larger surrounding region, as illustrated by the graphic below, figure 13 in the paper.
Layered deposits [LD] within Sera and Jiji preserve an exceptional record of past climatic conditions of the Arabia Terra region. Due to the thinning and thickening sequences identified from layer thickness measurements, mere subaerial deposition hypotheses (i.e., airfall deposition, volcanic or impact related ejecta) with no aqueous component is unlikely. We concluded that LD are deposited in an aeolian [wind-driven] environment controlled by a changing base-level of a near-surface aquifer. The variations observed in layering sequences likely reflect a significant control by groundwater-level fluctuations during deposition. The proposed long-term water level combined with the regional layer thickness trend does help support the idea that water level influences layer formation.
In other words, these terraces were formed from sand dunes blown here by wind, then compressed into rock layers that were later reshaped by a fluctuating water table of either water or ice.
As the location is now in the dry equatorial region, water or ice is no longer present, and hasn’t been for a very long time. All recent erosion is once again wind-driven.
The support of my readers through the years has given me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Even today NASA and Congress refuse to recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:
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You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
Click for original image.
Today’s cool image is an update of a previous cool image from July 2021. Then, I posted a captioned high resolution Mars Reconnaissance Orbiter (MRO) photo of the many terraced layers within a 13-mile-wide crater dubbed Jiji and located in Arabia Terra, the largest transition zone between the Red Planet’s northern lowland plains and the southern cratered highlands. At that time the caption noted that research was on-going to see if the same layers could be identified in two other nearby craters, Banes and Sera, and thus use that data to extrapolate the long term geological history of this region on Mars.
Today’s cool image to the right, rotated, cropped, reduced, and enhanced to post here, was taken on January 4, 2024 as part of this research, and shows the layers in 18-mile-wide Sera crater, located only about ten miles to the east of Jiji crater. The highest mesa near the bottom of the picture is about twenty feet high on its southern side, but about 140 feet high to the north. The difference is because the crater floor under the mesa is sloping downward to its lowest point to the north.
Figure 13 from paper. Click for original graphic.
The white dot on the overview map to the right marks the location of Sera crater, with the rectangle in the inset showing the area covered by the picture. The dark areas inside Sera of dust covered dune fields.
According to a paper published in March 2023, the geology of the layers in these two craters is linked, and appear to be also linked to the geological history of the larger surrounding region, as illustrated by the graphic below, figure 13 in the paper.
Layered deposits [LD] within Sera and Jiji preserve an exceptional record of past climatic conditions of the Arabia Terra region. Due to the thinning and thickening sequences identified from layer thickness measurements, mere subaerial deposition hypotheses (i.e., airfall deposition, volcanic or impact related ejecta) with no aqueous component is unlikely. We concluded that LD are deposited in an aeolian [wind-driven] environment controlled by a changing base-level of a near-surface aquifer. The variations observed in layering sequences likely reflect a significant control by groundwater-level fluctuations during deposition. The proposed long-term water level combined with the regional layer thickness trend does help support the idea that water level influences layer formation.
In other words, these terraces were formed from sand dunes blown here by wind, then compressed into rock layers that were later reshaped by a fluctuating water table of either water or ice.
As the location is now in the dry equatorial region, water or ice is no longer present, and hasn’t been for a very long time. All recent erosion is once again wind-driven.
The support of my readers through the years has given me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Even today NASA and Congress refuse to recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation:
5. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
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