Arkansas, Louisiana & Missouri, USA Impact Craters.
Southeast Missouri banding harmonic transition to coning harmonic by convergence of waves in center. Specimen collected by Dustin Allmon.
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The Prim Arkansas Spherical Bolders are from a large earth impact.
Gravity map of Arkansas and the half crater. A subsequent event has covered half of this big crater. This crater is a type called Crusta Confractus an impact that broke the earth's crust hence "Hot Springs." It made the giant spheres.
Possible Meteorite Impact Crater in St. Helena Parish, Louisiana*
By
Paul V. Heinrich1
Search and Discovery Article #50006 (2003)
*Adapted from article of same title by same author in Louisiana Geological Survey News, v. 13, no. 1, June, 2003, p. 3-5. Appreciation is expressed to the author and Louisiana Geological Survey, Jacko J. John, Director and State Geologist.
1Louisiana Geological Survey, Baton Rouge, Louisiana (heinric@lsu.edu)
Introduction
Between 1996 and 1997, Richard P. McCulloh, the author, and John Snead of the Louisiana Geological Survey compiled McCulloh et al. (1997). This research revealed an anomalous circular feature, which McCulloh et al. (1997) mapped as “Quaternary undifferentiated,” southwest of Greensburg, Louisiana (Figure 1), in the southwest corner of St. Helena Parish. This feature is named the “Brushy Creek feature” for the headwaters of Brushy Creek, which lie within this feature.
The regional landscape consists of narrow, closely spaced ridges and deeply cut valleys. The regional relief is about 90 to 110 ft (27 to 34 m). Drainages exhibit rectilinear patterns that often form well defined lineaments. Within this area, erosion has destroyed all construction topography except possibly for concordant summits along the major drainage divides.
tPhysiography, stratigraphy, petrography
Figure Captions
Figure 2. A digital elevation model of LIDAR (Light Detection and Ranging) data from the southwest quarter of the Greensburg 7.5-minute quadrangle; downloaded from the Atlas: The Louisiana Statewide GIS website (http://atlas.lsu.edu) and viewed with MacDEM Viewer.
Brushy Creek Feature
Physiography, Stratigraphy, and Petrography
Within this region of narrow, closely spaced ridges and stream valleys, the Brushy Creek feature occurs as a noticeable circular “hole” about 1.2 mi (2 km) in diameter. Its rim has a relief of about 50 ft (15 m) and exhibits a slightly polygonal shape (Figure 2). The main channel of Brushy Creek has breached the feature’s southeast rim and drains its interior.
The Brushy Creek feature lies in the region which Snead and McCulloh (1984) and Mossa and Autin (1989) mapped as the “high terraces.” Pliocene fluvial sediments of the Citronelle Formation underlie the high terraces. Regionally, they consist largely of variegated and mottled, poorly sorted, fine- to very coarse-grained, sandy gravel, gravelly sand, sand, and minor beds of silt, clay, and mud. Typically, individual beds are have limited vertical and lateral extent. As classified by Folk (1980), the sand within the Citronelle Formation consists of quartzarenites to sublitharenites that completely lack feldspar. Within the area of this feature, the Citronelle Formation is about 300 to 350 ft (91 to 107 m) thick (Campbell, 1971; Mossa and Autin, 1989).
According to Mossa and Autin (1989), over 6 ft (2 m) of loess blankets the Citronelle Formation within the region of the Brushy Creek feature. This loess consists of both Late Wisconsinan Peoria Loess and underlying older Sicily Island Loess. However, soil descriptions in McDaniel (1996) and examination of local soil profiles indicated that the actual loess thickness within the area of the Brushy Creek feature is about 3 ft (1 m).
Field investigations found that the Citronelle Formation within the area of the Brushy Creek feature consists of poorly sorted, fine- to coarse-grained sand overlying laminated clays and silts. The sand is 30 to 40 ft (9 to 12 m) thick and consists of deeply weathered, reddish brown, fine- to very coarse-grained, moderately well sorted sand. In outcrops, the sand can be both massive and cross-bedded. At least 20 ft (6 m) of laminated silts and clays that underlie these sands were found in the Kentwood Brick and Tile Company brick pit lying just east of this feature. They consist of meter-thick, fining-upward, cyclic beds of laminated silt and clay. Discussions with the staff at the Kentwood Brick and Tile Company revealed that drilling indicated that these sediments occur on either side of this feature, but are absent within it. Very little is known about the sediments of the Citronelle Formation underlying the silts and clays.
Within the area of the Brushy Creek feature, about 6 to 7 mi (10 to 11 km) of older Cenozoic to Mesozoic sediments underlie the Citronelle Formation. The uppermost 11,000 to 12,000 ft (3,350 to 3,660 m) of these sediments consists of Cenozoic sediments of the Midway, Wilcox, Claiborne, Jackson, and Vicksburg groups and undifferentiated Neogene strata. The undifferentiated Neogene sediments consist of siliciclastic sediments lacking any significant carbonates. These strata dip homoclinally to the southwest and lack any indication of major faulting or salt structures (Howe, 1962; Bebout and Gutiérrez, 1983).
Field studies indicated that the rim of the Brushy Creek feature consists of massive silty sand and sandy silt, in which a mature soil profile with well developed A and B horizons has developed. The only complete exposure occurs on the feature’s northwest distal edge. It consists of 7 to 10 ft (2 to 3 m) of massive silty sand and sandy silt overlying 5- to 12-in. (13- to 30-cm) thick bed of gravelly mud. The gravelly mud contains abundant rounded clasts of mud, clay, and frequently magnetic ironstone nodules. It lies directly on the truncated surface of deeply weathered, cross-bedded, and highly fractured Citronelle Formation. Within the silty sand and sandy silt, an 8-in. (20-cm) thick zone contains numerous rounded, dime-size, and matrix-supported clasts of purple silty clay derived from the underlying Citronelle Formation.
Numerous sediment samples were collected for study from the rim and interior of the Brushy Creek feature. Additional sediments were collected from a bar in Brushy Creek downstream from where it cuts deeply into the rim of this feature. Within a radius of 1.5 to 4.5 miles (2.4 to 7.2 km) of the Brushy Creek feature and at two localities at greater distances, sediment samples were collected from outcrops of the Citronelle Formation. Finally, dozen of ironstone nodules from exposures and streambeds draining this feature were collected.
All samples were processed to separate the sand fraction. Then, the sand from each sample was separated into 18 to 60 mesh (0.0 to 2.0 phi), and 60 to 200 mesh (2.0 to 3.75 phi), fractions by dry sieving. Petrographic thin-sections were made from these fractions for each sample and from, for selected samples, intact clods.
Both outside and inside the Brushy Creek feature, the sand consists of subangular to well rounded, quartzarenite to sublitharenite sand containing about 90 to 95 percent quartz. Except for two samples from the rim of this feature, neither feldspar nor mica was noted in these samples. Some of the sand associated with the Brushy Creek feature exhibited ragged edges resulting from disintegration of sand grains during processing.
Miscroscopic Features of Quartz Grains
Within samples from the Brushy Creek feature and Brushy Creek, intensely fractured quartz occurs in variable proportions. Both rectilinear fractures and interlocking, irregular network of fractures were found (Figures 3 and 4). Kieffer (1971) and Shoemaker and Kieffer (1979) illustrated similar, intensely fractured sand from shocked Coconino Sandstone from Barringer (Meteor) Crater in Arizona. Also, Dr. W. Feathergale Wilson, (2002, personal communication) has observed similarly fractured quartz from the Bee Bluff Impact Structure in Texas. The presence of iron oxides coating fractures in deeply weathered grains shows that they are not artifacts of thin-section preparation. In contrast, none of the control samples showed the intensity of fracturing observed in samples associated with the Brushy Creek feature.
Shocked quartz occurs in samples from sand collected from the alluvium of Brushy Creek. It consists of several quartz grains with single and two sets of planar features (Figure 5). The average orientation of quartz grains with two sets of planes is 45 degrees and 33 degrees, which, respectively, are the {1012} and {1122} crystalligraphic orientations (Stephen Benoist, 2003, personal communication). As discussed by Koerbel (1997) and Stoffler and Langenhorst (1994), both orientations are characteristic of planar deformation features (PDF) created by shock metamorphism. The multiple grains found with PDFs and planar features argues against them having been reworked from distant sources; e.g., a Cretaceous - Tertiary boundary layer. Instead, it indicates that they came from a nearby primary source; i.e., the upstream Brushy Creek feature. Sand from the gravelly mud within the feature’s rim contains numerous quartz grains with planar fractures that are currently under study.
Pedogenic Ironstone
Numerous ironstone nodules were cut and examined and, sometimes either thin-sectioned or tested for high concentrations of nickel using dimethylglyoxime. Highly weathered meteorites, called “iron shale” or “shale balls,” were not found. Instead, the ironstone nodules examined were all pedogenic in origin. as the nodules typically found in local soils.
Conclusion
A number of processes, including salt diapirism, solution karst, and volcanism, can produce circular landforms, similar to the Brushy Creek feature. Because this feature lies in a portion of the Louisiana Gulf Coastal Plain devoid of salt diapirs and major salt structures, salt diapirism cannot be invoked to explain this feature. Similarly, the complete absence of volcanic sediments from this feature and the complete absence of Pleistocene and Holocene volcanism within Louisiana Gulf Coastal Plain also preclude this feature from being a volcanic maar. Similarly, the lack of significant carbonates within the upper 11,000 to 12,000 ft (3,350 to 3,660 m) precludes carbonate karst processes as an explanation.
Siliciclastic karst can create landforms similar to the Brushy Creek feature, as discussed by (May and Warne, 1999) for the origin of the Carolina Bays within the Atlantic Coastal Plain and circular depressions found within the Mississippi and Alabama coastal plains. However, siliciclastic karst develops on flat, poorly drained, and undissected geomorphic surfaces lacking well defined drainage systems. In contrast, the Brushy Creek feature occurs within an area that is deeply dissected and drains well. Such relief and well developed drainage systems would cause lateral flow of surface and near-surface water and erosion and greatly inhibit the vertical-drainage weathering needed to create siliciclastic karst (May and Warne, 1999). The Brushy Creek feature also is an isolated circular landform unlike siliciclastic karst; e.g., the Carolina Bays, which occur typically as clusters of multiple depressions. Lastly, the siliciclastic karst hypothesis fails to explain the direct association of shocked and intensively fractured quartz with the Brushy Creek feature.
The hypothesis that the Brushy Creek feature was created by either a meteorite or comet impact, and, in fact, is the Brushy Creek Impact Crater, is the most promising hypothesis. The Brushy Creek feature constitutes a well defined unique “hole” in the regional topography, which appears to be associated with a “hole” in the local stratigraphy. The presence of feldspars and mica in two samples from the rim of this feature indicates that less-weathered sediments from strata underlying the Citronelle Formation have been brought to the surface from hundreds of feet below the surface. All of these observations are consistent with the formation of the Brushy Creek feature by impact processes. The intensively fractured nature of the quartz sand from the rim of this feature and the presence of shocked quartz provide direct evidence of impact processes.
If it is an impact crater, the age of the Brushy Creek feature remains unresolved. The age of the Citronelle Formation provides a maximum age of about 1.9 million years for it. Judging from the degree of preservation of constructional landforms on terraces forming the surfaces of the Avoyelles and Deweyville Allogroups, the presence of a recognizable rim on the Brushy Creek feature indicates that it is likely less than 20,000 to 30,000 years old. An apparent absence of loess covering its rim would argue for it being less than 13,000 to 11,000 years old. However, loess might only appear to be absent because it has been either mixed by pedogenic processes into the underlying rim deposits; eroded by surface processes; difficult to distinguish from the silty rim sediments, or some combination of these.
References
Bebout, D.G., and Gutiérrez, D.R., 1983, Regional cross sections Louisiana Gulf Coast {eastern part}: Louisiana Geological Survey Folio series, no. 6., 11 p.
Campbell, C.L., 1971, The gravel deposits of St. Helena and Tangipahoa parishes: Ph.D. dissertation, Department of Geology, Tulane University, New Orleans, LA, 295 p.
Folk, R.L., 1980, Petrology of Sedimentary Rocks: Hemphill Publishing Company, 84 p.
Howe, H.J., 1962, Subsurface geology of St. Helena, Tangipahoa, Washington and St. Tammany parishes, Louisiana: GCAGS Transactions, v. 7, p. 121-135.
Kieffer , S.W., 1971, I. Shock metamorphism of the Coconino Sandstone at Meteor Crater, Arizona. II. Specific heat of solids of geophysical interest: Ph.D. Dissertation, California Institute of Technology, Pasadena, California, p. 191.
Koerbel, C., 1997, Impact cratering: the mineralogical and geochemical evidence, in K. S. Johnson and J. A. Campbell, eds., Ames structure in northwest Oklahoma and similar features: Origin and petroleum production (1995 Symposium): Oklahoma Geological Survey Circular, no. 100, p. 30-54.
Louisiana Geological Survey, 1999, Geologic map (GIS) of Louisiana: Louisiana GIS CD, v. 1.
May, J.H., and Warne, A.G., 1999, Hydrologic and geochemical factors required for the development of Carolina Bays along the Atlantic and Gulf Coastal Plain, U.S.A.: Engineering Geology. v. 5, p. 61-270.
McDaniel, D., 1996, Soil survey of St. Helena Parish, Louisiana: Natural Resources Conservation Service, U.S. Department of Agriculture, Washington, D.C., p. 143.
Mossa, J., and Autin, W.J., 1989, Quaternary geomorphology and stratigraphy of the Florida parishes, southeastern Louisiana: Louisiana Geological Survey Guidebook Series no. 5, 98 p.
McCulloh, R.P., Heinrich, P.V., and Snead, J., compilers, 1997, Amite, Louisiana 30 x 60 minute geologic quadrangle (preliminary): Prepared in cooperation with U.S. Geological Survey, STATEMAP program, under cooperative agreement no. 1434-HQ-96-AG-1490, 1:100,000-scale map plus explanation and notes.
Shoemaker, E.M., and Kieffer, S.W., 1979, Guidebook to the geology of Meteor Crater, Arizona: Publication No. 17, Center for Meteorite Studies, Arizona State University, Tempe, Arizona, 65 p.
Snead, J.I., and McCulloh, R.P., 1984, Geologic map of Louisiana: Louisiana Geological Survey, Baton Rouge.
Stoffler, D., and Langenhorst. F., 1994, Shock metamorphism of quartz in nature and experiment. 1. Basic observation and theory: Meteoritics. v. 29, p. 155-181.
Status of Research
At this time, the author and other researchers are conducting ongoing research and planning future research of the Brushy Creek feature. For example, John Wrenn of the Louisiana State University (LSU) Department of Geology and Geophysics and the author are looking at various ways to date it. Douglas Carlson, Richard McCulloh, and the author are considering the use of various geophysical techniques with the LGS Giddings Soil Probe to study the internal structure of this feature. Finally, Stephen Benoist of the LSU Department of Geology and Geophysics and the author are studying evidence of shock metamorphism in samples from the Brushy Creek feature. A preliminary report on the Brushy Creek feature will be presented as a poster at the October 2003 Gulf Coast Association of Geological Societies Annual Convention in Baton Rouge, Louisiana. Additional papers concerning the results of the above ongoing research are planned.
Acknowledgments
Geologic mapping funded by the United States Geological Survey, STATEMAP program, under cooperative agreement 1434-HQ-96-AG-01490, first discovered the Brushy Creek feature. Current research was conducted with the encouragement of Chacko John, director of the Louisiana Geological Survey (LGS) and direct support of the LGS. David T. King Jr., Donald R. Lowe, Don Johnson, W. Feathergale Wilson, and R.P. McCulloh were quite helpful with their opinions and encouragement. I also acquired useful advice about identification of shocked quartz from Christian Koerbel, Scott Harris, and Stephen Benoist. The LSU Department of Geology and Geophysics helped out with access to their photomicroscope and preparation of several thin-sections. The excellent quality of thin-sections prepared by National Petrographic Services, Inc. proved important to my research. Finally, I am very thankful to the Kentwood Brick and Tile Company: William A. McGehee of Greensburg, Louisiana: and Soterra LLC, inc. of Jackson, Mississippi, for access to their property and their excellent and invaluable cooperation.
Dedication
This and ongoing research at the Brushy Creek feature is dedicated to the memory, courage, and curiosity of the crew of Space Shuttle Columbia (STS-107) and to the manned exploration of space by astronauts and cosmonauts of all nations, creeds, and races of which they were a part.
Coning type harmonic fractals.
Impact Spheroid >
Banding harmonic
High shock quartz impactite cinder from Ozarks the Big Arkansas Crust Breaking Impact. Specimen was at 2,000 + degrees (quartz vaporization temp F) with banding resonance (the pretty thin lines). It also has a granular particle crystallization form (habit) of high shock making geometric figures, in this case circles. Take a look.
Not a fossil. This is overlapping shatter cones. Multi directional shock. This was a plasma at the time and they are melted together. It appears to also be making a cubic crystal form. Specimen collected by Linda Darling Atwill Found in a creek near the Illinois River near Tahlequah, Oklahoma.
Specimen collected by Matt Norris in the Ozark Mountains.
Now here is a picture from Mars of a small "high side" impact. A low angle impact. But this one did not penetrate the crust which amplifies this effect. https://mars.nasa.gov/resources/3425/mars-odyssey-all-stars-bacolor-crater/?site=insight
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The Ozark Highlands as the back crater rim of an oblique impact with subduction. This impact broke the earth's crust.
Advanced Impactite Theory - Granular particle construction is a result of the pulverization of earth impact which is sorted by distance and compressed in the high pressure. Not typical of any sedimentary process. Section 1 has the geometric circle form of the high energy granular habit (crystallization). Section 2 has the linear form also high shock pressure energy. Section 3 the receiving rock has the classic Turing Pattern (Alan Turing 1952) a lower energy form showing these impalements and the receiving rocks were made in different environments. Finally, section 4 has a penetrating impalement, a shallow ballistic. But here the surface is circle geometric habit from the impalement energy.
Doris Fincher
Warrington, MO. USA Aug. 22, 2022
Im just learning so thank you all for all advice you give. What would this rock be?
So lets take a look at your crater. It came from the southwest, very powerful and blasted down to the pre-Cambrian strata! Earth impacts are called the "great excavator."
The Lou Big Two.
Brushy Creek Impact Location.
Brushy Creek metamorphic rock with impalements.
Understanding crater geological columns - More of an inversion and instant made. While the unconformable surfaces could represent a single impact event they can also be the separate shock wave breaks made by the crater process. Loose material association with these shock made separations. The sand from an ocean type environment is thrown into crater wall.
Very hot center melt and the iron encasement. Iron sheets and sandstone can be observed in Franklin County, TN and Jackson County, AL from the Howell, TN Impact. A distance effect edge related phenomena.
Heat expansion septarian and impalements. Instant forms not weathering. Weathering is a common geologic theory that goes back to the pre tectonic period.
Unformed breccia type sphere. This is a margin/edge type. Notice it is also oblate. The more perfect spheres achieved a high energy melt state and ejected independently enough to form spheres.
Chert rubble with nano iron impaled by sphere. Surface of sphere seems to have some evidence of cavitation a directional flight made impression phenomena. (shown just above the chipped off section.)
This is a crater exposure. Energy strata. While shatter coning is poorly understood, that is what you have going on. The black is a nano iron Fe3O4 black iron oxide released as a plasma mist that falls back onto the hot crater relics. You will also find that these matrixes when magnified are composed of a "common particle." The common particle is a result of the impact pulverization. I have marked up the triangle waves. This is likely part of the Big Missouri Crater complex as you are in NE Arkansas. So what are all those unorganized lines? Remember this is an explosion made material. Shock harmonics are a settling down of the impact wave forms. This area is only partially organized into recognizable wave patterns. This was a very big impact if it is the Big MO edge.
Maria Barnes
Sept. 20, 2022
Found in Highland Ar.
Never seen rocks like this.
Iron thin plane insertion high charge fractal mosaic shock made mega clast , oblate nodule. Large earth impacts shoot these former limestone strata nodules outward as ejecta blobs. The impact also has pulverized the iron from the bolide which is turbulent in a shock chaos storm. These particles become energized electrically like a volcano plume causing lighting. Iron particles as lightning will imprint as deposition. While this specimen is in North Arkansas it is likely a relic of Big MO the crater that covers most of Missouri.
Scot Mattox · Oct. 13, 2022 ·
Feels very heavy for size, over 100lbs, unique cracks, looks almost egg like. What is it? Found near Buffalo River in Arkansas.
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Arkansas has a big crust breaking impact and a subsequent larger covering event. You can tell this by the direction of the fractal flow. Branching occurs away from the source of energy which is upward in both cases here.
Impact melt flow with enclosing borders.
Crater effect shock circle with high energy fractal striation, imprinted wave circle, and shock granular crystal habit geometrics in center of circle. This big plasma blob was ejecta and landed here. Energy strata, instant made. As it is located in the confluence of several large earth impacts I am unable to specify which. Major candidates are: Big MO the state size Missouri crater and Hot Springs. As this is formerly bedrock now shock melt metamorphic I favor Big MO as Hot Springs broke into the earth's crust deeper and thrown bedrock craters did not. Hot Springs is an earth accretion type 1 or 2 a penetrating fast ballistic (30+mps).
Kim Pervis · · Oct. 14, 2022
Someone posted this in the Arkansas Fossil Collectors group.
It was found near Big Flat, Arkansas USA. It is most likely from the Pitkin Limestone Formation, which is Mississippian.
He said it was about 8 feet (2.5 m) across.
I’m wondering if it could be some form of MISS. Or could it be a stromatolite? I’ve never seen a stromatolites this big.
Any thoughts?
Priceless! You have found the most phenomena demonstrating piece of shock floor I have ever seen. Unlike what is taught Hot Springs is the location of an earth penetrating impact. While not large by planet impact standards the Hot Springs Impact was very fast and relatively late. I live in another fast impact crater at Howell, TN Crater. Fast impacts are in excess of 30 miles per second. This is called a non captured speed as it is an object coming in from outside the solar system. The forms shown in your specimen are a developmental energy high shock. The energy makes fractal columns and shatter cones. The ending Septarian surface is a similar phenomena the same as column basalt which is also misunderstood as a volcanic form. Column basalt is a shock form and never observed in the history of volcanic eruptions.
Sylver Grace · Oct. 21, 2022 ·
Multiple pics with flash and without. Very heavy, found in hot springs. What is this?? I have a couple smaller ones too
Oblate impact sphere, part of the North Central sphere fall. The surface is a heat delamination. The surface also has tiny iron sphere impalements. These are also impact spheres but are from the impacting bolide iron a later arrival as that would come from the center of the explosion whereas the oblate sphere is contact material.
Milky quartz impact sphere. Large earth impacts throw off these liquid drops that form spheres. It has been impaled on the surface with some of the impacting bolide's iron.
Oct. 26, 2022 ·
So I found this really round rock that looks like a miniature moon, seems heavy for its size, it's really hard, scratches glass and it scratches iron, it doesn't react to white vinegar. What kind of rock is this, how could it get so round naturally when it is so hard? I found it on the interstate, I was checking one of my tires and came across this strange round little stone. It was found off to the side of the road in North Little Rock, Arkansas off of Interstate 440.
Rare quartz impactite form. A circle resonate harmonic with coning.
Here are a few more of those crazy rocks I've found in northeast Arkansas. Have looked everywhere and can not find what they are. Well, any that have these markings. I just think they are neat. And a funny looking horn corral looking rock. Oh and the one that has the dots all over. Honeycomb corral ?
Edie Bee Oct. 29, 2022
Harmonic shifting example specimens are rare, the capture of an energy form shift.
Impact sphere and catcher. A progressive build like some hailstones do. It passed through a carnelian blast phase.
Nov. 27, 2022
I am so excited about this septarian nodule! My coworker found this one and another one just like it (that I had half of). The Bic lighter is for scale. Found in Northwest Louisiana.
Interesting coning variant, Callaway County, MO. It is of course from the Big MO impact and an outlier edge effect. Shock resonance which makes shatter cones tends to gather around the center of mass but this specimen is a surface chevron wave imprinting which is rare. The material on surface is more uniform allowing imprinting. It appears to have been a separate coating some of which has broken away.
Fossil? Shock made wave patterns are usually not this consistent and as I mentioned above not surface only. While not a known fossil type that occurs more often than you might think. I actually feel the preponderance of evidence is fossil, a new genus.
Impactite, melt slurry with surface high energy rejection patterning and patina (red and blue). These melt blobs are blasted out of a forming crater and land while cooling. As impact is an explosion a rough kind of mixing occurs (slurry mixing) since it was not a complete liquid as it tangled. Finding on the top of raised earth structures is common to a lower part of the excavation blasted late in the impact event. So what are rejection patterns? They are the surfaces not able to conform a non mixing state. In this case it is the high surface heat and the air making the patterns you see on magnification attached. The heat to make a blob like this is very high, over 3,000 F which excludes a tectonic or volcanic process.
April 10, 2023
Tricia Fasching · ·
I’m in Northwest Arkansas in the Ozarks and saw this yesterday on a bike ride. It looks like bones in cement but it is not cement. Any ideas just so curious. Thanks.
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The big four state crater as shown on the USGS geology anomaly map.
Clastic Intrusions from the North Central Arkansas Impact Crater. These columns are pushed up as a resonate tube much like a sphere is ejected from impacts as a melt drop these are the next dimension of spheres a tubular column. In multiplicity you have column basalt. Oct. 23, 2023.
Kelly Fisher
I’m an amateur, but my kids love rocks….so here I am. Are these fossilized trees or just cool formations? There is a whole “forest” near our home. Up a hill from the Buffalo River near Big Flat, Arkansas. USA.
And speaking of impact spheres, here is one that has been impaled by them. Is part of the impact record. Oct. 23, 2023.
The North Central Arkansas Impact Crater and NW Crater as shown on map by Chegg Products and Services. Oct. 23, 2023.
Impact mega clast with high heat mosaic surface and split on landing. Oct. 25, 2023.
Cynthia Ramirez
I wanted to share the concretions that I found here in Northwest Arkansas! Enjoy! This is located in Elkins, Arkansas. I'm not sure of the exact location because there is a little off roading to get there.
Impact phenomenon. These are only found in and around powerful craters. The grid is made by shock wave banded splatter. As you can see it is somewhat random as impact is an explosion. While the grid is one impact common form the circles are like shock agates and are a resonate form. Resonance like your microwave oven cooks from the center of mass outward. The geological disturbance in and around Little Rock is an earth penetrating crater, too powerful to make the typical surface circle. So let's talk about Liesegang banding. It is from salts crystallizing out as gradient bands getting ever wider. Your boxwork construction does not do that. Nor was it ever a salt. The Liesegang phenomena does not explain the accompanying gridwork. Another feature of your specimen is the dual grid lines. While common it is likely an energy signature. Lightning sometimes does this. Nov. 8, 2023.
Arkansas Rocks and Minerals
Can anyone enlighten me on how this rock was formed? It’s one large rock, 2-3 ft across in Faulkner Co.
Chegg Products & Services Geology Anomaly Map. You can study these and see why rivers flow the way they do. Nov. 8, 2023.
Impact nodule. When more rhythmically expelled on the shock waves you see this as boxwork. Nov. 13, 2023.
Sam Grillett · ·
Found at Wright Patman Lake in East Texas. There is iron ore all over this beach. I found this strange little guy and I’m just trying to figure out more about it. It looks like it was molten iron that got flash frozen. I don’t know enough to guess. That’s why I’m here.
Round Impactite Spheroid from the KC Crater shown on Bouguer Gravity Map below. Nov. 24, 2023.
Ron Smith · ·
Anyone have any idea what this is? Found in Lee’s Summit, Missouri, USA.
Cancer rates in Missouri. Jan. 29, 2024.
Impact shock floor. The base in picture 1 has a linear fast form which stopped and changed to the tubes and bubbles as the energy was expended. The top surface was on fire and made an ablative surface with the colors you see. This is the same process that makes impact column basalt only those have much greater energy and broke the earth's crust. Nov. 25, 2023.
Julie Estes Johnson · ·
Can someone please help me identify this rock? I found it partially buried in the woods on our farm in Sharp County. I have lived on the farm all my life and have never seen anything remotely like it. The colors will not come off. Considering the uniqueness of its appearance if I didn’t know better I would think it was planted as a joke. Many thanks.
Sharp County, AK is in NE Arkansas and part of the Big MO Crater Complex. Nov. 25, 2023.
Impactite, plasma hole burns and melt flow covering, rare. Nov. 26, 2023.
Terri Bland · ·
Found in Clark County (Arkadelphia). This rock is much lighter than it appears. The holes make me wonder if this is native American.
Any ideas what this is?
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Shock made clast expelled as a melt limestone from crater. It encountered plasma bubbles which made the impressions. Shock white is a common crater indicator for limestone. It is likely tempered and will clink when struck. A type 3 impactite made only of the earth strata reformed. This often occurs late in the impact progression and can be expelled over a crater diameter or two. Jan. 15, 2024.
Steve Gillispie
December 22, 2023 at 10:54 PM ·
Found in the Ozarks.
Fluidized splash effect from Impact. Compare to this 3D model. Rocks In The Field. HW 5881 in SW Arkansas. Some were asking where this big rock is so this weekend we went back and got the grid coordinates. It’s in Newton County southeast of Deer off of Parker Ridge Road. It’s down an old logging road and they are currently logging there again. With a 4-wheel drive you can drive within 40 yards of the rock. Just look up hill. Thinking of naming it Crazy Rock unless someone has a better name?
John Toeppen ·
May 31, 2023
A few more pictures. This was a few yards up the hill from Crazy Rock
On Mount Diablo East of Oakland CA. This link is to a highly detailed 3D model of the inclusion. https://sketchfab.com/.../rock-egg...
Heading 5
This large crater that caused this is visible as a Topo Crater meaning it has not been removed by subsequent geological events. Feb. 7, 2024.
Impact disk with Septarian high heat mosaic cracking. It landed somewhere around there but could have been moved downstream some by the water. You can see some more mosaic cracking in the strata behind as well as compressed impact ash slate shown as the dark strata. An impact disk this large is from a large or powerful impact. It was once the limestone strata but was made liquid by the high shock which expelled it as a drop. The drops are deformed in flight or upon landing. Feb. 24, 2024.
Arkansas Rocks and Minerals
Zack Rowe · ·
Stromatolite?
Raft/Plate/Impact tectonics and large earth impacts - These two large craters are both earlier than the alluvial covering sediments. As the Arkansas crater is larger and much more powerful, breaking the earth's crust: I suppose it came first. Is there a large previous crater below both centered around the New Madric instability? I think yes. I also think it was larger. Large is actually a sign of less power in this case as the Arkansas punched through the crust. March 6, 2024.
Crater wall folding, lateral fold. Crater walls have a lot of turbulent settling. This was simi plastic when molded hence the breaks and bricking. The iron is from the impacting bolide/meteor. Petit Jean State park NW Arkansas. March 10, 2024.
Diamonds in Arkansas
This rock formation is located at the site of Arkansas' oldest state park, Petit Jean. It is at the North rim Cedar Creek canyon.
Impact nodules/oblate spheres from the Big MO impact. This impact takes up most of southern MO about half of the state. The banding is shock wavelength imprinting. The black dots are iron from the impacting bolide/meteor. The example in the comments as an egg is encasing sulfur. Sulfur is common to meteorites. Once exposed to air it will decay to powder. March 11, 2024.
Sam Parker · ·
Heavy/dense. Found in South Central Missouri. Was told they’re concretions but not matching up with any examples I’m finding.
Had a similar one and couldn’t stand it had to open it!!!
Impact mega clast with impalement from the Big MO impact which covers half of the state. First let's discuss shock made mega clast. Shock white is a give a way here besides the flow surface. Shock white is from the high energy purifying the limestone which was ejected from the impact area strata as a melt. It is hard shock dolomite, very heavy. Chert impalement with water color type flow banding impalement is another piece of ejected impactite formed at a different part of the impact explosion. While the mega clast was likely still plastic when this hit, the velocity was also likely high. The Big MO crater is shown on the attached map. Let me point out that craters are not all round as you can see on the Moon. This crater likely has some involvement with the New Madrid instability as impacts can crater as deep as they are wide. So Big MO appears to be about 150 miles diameter and that depth would penetrate the Earth's outer crust. March 14, 2024.
Kelsie Edge · ·
I won’t let my husband get rid of this (I’m convinced it’s a dinosaur egg) he found it around 2010 in a private creek in Mid Missouri while he was looking for stones to carve.
Type 2 Impact subduction coming in from the NW.
All of these patterns are consistent with an impact from the NW making deep breaking of the Earth's crust. March 14, 2024.
Crater Basin flow pattern. The Big MO Basin is a sink for collecting water flow. Look how the TN Basin collects to empty at that low point. March 13, 2024.
Big MO as a slider - Chegg Products & Services Geology Anomaly Map. A subduction crater would be a low angle impact. It could even be a slider. March 14, 2024.
Impact iron from the Big MO impact structure. Incomplete crystal habit. Actually, for impact iron this is a slower formed nodule. It had time to attempt a crystal habit. Is called a pseudomorph Pyrite to Hematite. Not cold fusion, heating is required, 980 F. Where did the heat come from? Where did the iron come from? Sulfur is common to meteorites. So why not Mississippi Valley Type (MVT)? While I can easily point out the Big MO crater on the map nobody has ever fount the earth crack "spring release" location for these surface irons. MVT is a 19th century theory that was renamed MVT. Like the Howell, TN Impact Structure the Big MO impact is not a circle. That is why we use the term "structure." Also like the Howell Structure it appears the Big MO impact was a slider, a low angle impact which in the case of Big MO was so big it made a type 2 subduction crater. Big MO is part of the New Madrid fault structure and is still resolving the deep crater rubble stresses. Attached is a map of mineral mining in MO where I have marked the Big MO crater profile. It is from a MO mineral dealer. March 15, 2024. https://www.virtualmuseumofgeology.com/missouri-minerals.html
Wanda Schroeder · 10h ·
This was found in eastern MO Bourbeuse River in Gasconade County. It is heavy for its size, and pretty sure it's not a rock. It is not magnetized. Would love to hear your thoughts.
Overcooked impact nodules with botryoidal bubbles and fiber crystals (see arrow above) and some trace iron. Crater showed below. April 30, 2024.
Julie Hughes found in small creek ST. Paul area.
Impact nodule, black iron oxide and silica. At high temperature and pressures below 40 GPa, iron and silica react to form iron oxide and an iron–silicon alloy, with up to 5 wt% silicon. Fractal flow is caused by directionality. The molten form was subjected to shock direction force which made the teardrop shape and caused the fractal tubular branching. Attached is the USGS magnetic geology anomaly map of your area with the relevant craters. The NW Arkansas crater complex is a system of craters. These meteor/bolides obviously were high in iron as you can see from the magnetic imaging.
July 18, 2024.
Laura Williams · ·
My daughter found this in a small creek in northwest Arkansas... I'm not sure if this is a fossil, or just a really cool rock. What do you think?
As you can see impact craters are as common on the Earth as they are on the Moon or Mars. July 18, 2024.
Two stage impact nodule after sphere. Called a "Weaubleau egg" Was once part of the limestone strata but shock melted into drops which are expelled outward from the crater sometimes getting a second layer in the mass of outward molten material. Aug. 12, 2024.
Rockhounding For Beginners - The Original
Jennifer Rothrock · ·
Thank You for excepting me I live in the very top of Missouri that borders Iowa. This has to be the most unusual one I have found it was partially buried dug up and seen the perfect circle I still don’t have a definitive answer as to what it is? 🤷🏻♀️ but it is truly fascinating to me
https://en.wikipedia.org/wiki/Weaubleau_structure#Round_rocks
Another impact crater with size underestimated. The rivers are showing the crater dimensions much better. Rivers want to flow inside the crater rim or around it. Aug. 12, 2024.
Impact nodule. Chert and iron. The iron is from the impacting bolide and is in a bubbling state (botryoidal). These are also found in mid state. Attached is the USGS magnetic anomaly map with the big N MO crater circled. Aug. 17, 2024.
Bo Griffin · ·
Found in Moscow Mills Missouri. Can someone ID this rock.
Agate typology banding, yes, agate mineralogy, no. Agate formation types and rejection patterns. There are two types of agate physics. The first is rejection pattern flow mixing where the different minerals are not able to mix as they are different chemically. This is the type your specimen is. The second type is resonate banding, the typical shock agate. Fossil? Not a known grain structure and the outside of the central ring patterns are flow made coming from right to left. Liesegang banding? This chemical physics requires a salt type gel and the iron bands are not a salt. Where did the iron come from? Earth Impact is the common cause of all surface ores. The old theory circa 1800's "Spring Release" later named the "Mississippi Valley Type" conjectures ores emerged through some crack in the Earth's crust but have never been able to identify any of these cracks after over a century. So where is this Earth impact crater? The Big MO crater takes up most of southern Missouri. You can see it on the attached bedrock geology map. Sept. 20, 2024.
Amy Greeves · ·
Hi all. Missouri find. Loutre River. Is this an agate? Also, how do I pronounce "agate"? Thank you!
The Big MO inner ring. Sept. 20, 2024.
The Big MO outer ring shows later geologic disturbances like big craters on the Moon or Mars show. As you can see the proximity to the New Madris fault is indicative of its involvement. Also remember that the average angle of impact is 45 degrees. The direction of this impact appears to be coming in from the NW which would also indicate it as a cause of the New Madrid deep fault which is shifting in the lower Cambrian strata. Sept. 20, 2024.
