Let's switch this up a little and look at the exhumed river bed:
I have some initial questions about this feature.
What makes geologists so sure that this is a river bed? Is it just the shape?
Do rivers have some kind of transformational power on the rocks and soil below it to make them harder and more resilient to erosion? The last time I checked a river with a washed out bank will erode it's own basin if it gets a chance. So what is the deal with this feature?
Let's find out what kind of information is available on this feature. I still haven't found its exact location but I'm looking.
Mostly it's the unique chemical composition of the sandstone ridge (which makes it harder than the surrounding mudstone), combined with the obvious shape of a meandering river. From Wiki
An exhumed river channel is a ridge of sandstone that remains when the softer flood plain mudstone is eroded away. The process begins with the deposition of sand within a river channel (typically a meandering river) and mud on the adjacent floodplain. Eventually the channel is abandoned and over time becomes buried by flood deposits from other channels. Because the sand is porous (grain-to-grain contact leaves spaces between), groundwater flows more easily through the sand than through the mud of the floodplain deposits.Ã‚Â
Ã‚Â Minerals (typically calcium carbonate) can cement the grains together converting the loose sand into sandstone. Meanwhile, pressure from overlying sediments compresses the floodplain mud converting it to mudstone. Millions of years later, erosion can remove the softer, less cemented mudstone and leave the more resistant sandstone as a linear ridge. Thus, the local landscape where these occur is an inverted topography: what was previously low is now high, and vice versa. Exhumed channels are important indicators for ancient stream flow direction.
These features are called paleochannels
and have been found in various places all over the world. Do a Google Scholar search on "exhumed paleochannels" and you'll get hundreds of hits. Here is more info on the ones in the Green Mountain Formation in Utah. Notice the mention of preserved goosenecked meanders here too
A NEW ARRAY OF EXHUMED PALEOCHANNELS IN THE EARLY CRETACEOUS CEDAR MOUNTAIN FORMATION, UTAH
STAPLES, Evan R, BRITT, Brooks, SORENSEN, Amanda,Ã‚Â Geology, Brigham Young University, S-389 ESC, Provo, UT
Abstract: Exhumed channels have long been known from the Cedar Mountain Formation. Here, we report on approximately 30 additional exhumed paleochannel segments in the basal Cedar Mountain Formation extending roughly from Castle Dale, UT to ~20 km south of Green River, UT. Data presented here are derived from aerial stereophotograhs and preliminary field work in the area mentioned above. The channels are located in areas lacking the Buckhorn Conglomerate. The majority of the channels are located ~20 m above the Cedar Mountain-Morrison Formation contact and are underlain and flanked by silty to sandy mudstones. Preserved conglomeratic to sandy channel segments range in length from 0.1 to 2 km with widths of 2-20 m, and show a general northeastward flow direction. The longest preserved paleochannels are lightly to moderately sinuous. Several tight-radius point bar (gooseneck) complexes are exceptionally preserved and consist of nested sandstone crescents eroded to ridge and swale topography. Despite the preservation of point bars, the thalweg of the gooseneck channels are not preserved, possibly because once abandoned, the channels became oxbow lakes which filled with mudstones that were lost to erosion during exhumation. Thus, although the preserved channels suggest a dominance of low to moderately sinuous streams, it is likely that there is a bias against the intact exhumation and preservation of highly sinuous channels (oxbow lakes).
In the westernmost portion of the study area, the sandstone channels are located tens of meters above the base of the formation, are few in number, small, isolated, and surrounded by fine grained floodplain deposits. In contrast, to the east, near Green River, UT and on to Moab, UT the sandstone channels are relatively close to the base of the formation, closely spaced to amalgamated, thicker and called the Poison Strip Sandstone. We attribute these east to west fluvial architectural shifts to greater accommodation space in the western area as a function of higher subsidence rates.
Notice that paper is from the geology department of Brigham Young University, a hotbed of God hating atheism if ever there was one.
Paleochannels are of particular interest to NASA because several similar looking features have been seen on the surface of Mars
EXHUMED PALEOCHANNELS IN UTAH: INSIGHT FOR INVESTIGATION OF RAISED CURVILINEAR FEATURES ON MARS
WILLIAMS, Rebecca M.E., Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ
Abstract: Bifurcating ridge networks, termed Ã¢â‚¬Ëœraised curvilinear features' (RCFs), covering areas ranging from tens to hundreds of square kilometers have been identified at nearly two hundred sites on Mars in high resolution (<100 m/pix) images. Many RCFs are interpreted as paleochannels preserved in inverted relief based on similarity to terrestrial fluvial landforms and continuity relationships with negative-relief valley networks. The global distribution of RCF locations preserves a record of the history of aqueous flow on Mars.
Exhumed paleochannels in east-central Utah have similar morphology to comparably sized, ridge landforms on Mars. The Colorado Plateau is a unique geologic setting where multiple exposures of exhumed paleochannels are preserved. Following uplift of the region in middle to late Cenozoic time, erosion by the Colorado River and its tributaries stripped away younger rock strata, revealing Late Jurassic and Early Cretaceous fluvial sediments at several sites in east-central Utah. The present-day arid climate has inhibited the development of thick soil horizons and pervasive vegetative cover, both of which would obscure these sedimentary bodies. Exhumed paleochannels expose fluvial sediments and internal sedimentary structures in three dimensions.
Field work to date has focused on an extensive (spanning ~12 km) inverted paleochannel system which consists of four carbonate-cemented, sandstone-capped ridges within the Early Cretaceous Cedar Mountain Formation located 11 km southwest of the town of Green River, Utah. Morphologic and sedimentologic observations of the exhumed paleochannels are used to evaluate multiple numerical models for reconstructing paleofluvial hydrological parameters. Preliminary analysis shows a wide envelope of discharge values is generated, with the Limerinos (1970) approach producing a discharge value tending toward the center (median and mean) of the range. Although there are likely variations in the formation history between the terrestrial inverted paleochannels and the martian RCFs, including differences in cement composition and erosional agent, further study of these landforms on Earth will help elucidate the magnitude and relative timing of fluvial activity on Mars.
Wonder how the Flood happened to hit Mars too?
More on the GRF paleochannels
Image 1: An oblique aerial photograph of a carbonate-cemented, sinuous inverted paleochannel segment located approximately 11 kilometers southwest of Green River, Utah.
Inversion of relief is a common attribute of landscape evolution and can occur wherever materials in valley bottoms are, or become, more resistant to erosion than the adjacent valley slopes. Multiple processes can lead to the development of relief inversion including cementation of the valley floor (e.g. ferricrete, silicrete, calcrete, gypcrete), armoring of the valley floor by coarse grains and infilling by a more resistant material, commonly a lava flow. Differential erosion removes the less resistant valley slopes and preserves the valley floor as a topographic high. Various terms have been ascribed to channels preserved in inverted relief including 'raised' channel systems, 'suspendritic drainage lines,' 'gravel-capped ridges,' 'perched wadis,' or 'wadi ridges,' and 'suspenparallel drainage'. Inverted channels have been identified in a number of locations around the world including the Arabian Penninsula, North Africa, Australia and North America. Subsequent drainage patterns develop depending on the nature of the channel floor resistant agent. For example, water parallels the margin of lava-filled paleochannels resulting in twin lateral streams. In contrast, more complex drainage patterns can develop in locations where duricrusts formed as dissolution can yield discontinuous preservation of the paleochannel as duricrust-capped mesas.
The exhumed ridge in Image 1 extends approximately 1 km in linear distance, and stands approximately 35 m above the subjacent plateau. Modern drainage is particularly well developed in the lower right portion of the image and has created a water gap at image center. The arid climate promotes sparse vegetation and inhibits soil development, two factors that enable the landform to be readily discernible in aerial images. Based on burial reconstruction models for the region, the cemented channel sediments were first re-exposed at the surface a maximum of 650,000 years ago. Illumination is from the left.
source with HUGE closeup photo
So you see Adam777, it's not just a bunch of OEs sitting around drinking beer and going "gee, what lie can we come up with to torment the YEs with today?" Geologists have thoroughly studied these things.
If you want to overturn their conclusion, your new model need to explain ALL the observed evidence better than theirs.