5H: Trace Fossils
in NW Georgia’s Metamorphic Rock
By Thomas Thurman
Posted 20/Dec/2025
The original reports can be downloaded at the base of this page.
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In 1996 trace fossils, as burrows, of the genus Palaeophycus were reported as occurring in the metamorphic quartzite rock of Henderson Mountain’s Pinelog Formation of Pickens County. The discovery was made by Dr. Tony Martin and Ralph Crawford during a Georgia Geological Society Field Trip.
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In school we’re taught that metamorphic rocks don’t contain fossils, that the heat and pressure which recrystallizes and converts existing rock into metamorphic rock distorts and destroys any fossils the original rock contained. This remains true, but once again Georgia’s fossil record provides surprises.
Trace Fossils Defined
Trace fossils are indirect, preserved evidence of past life. Burrows, tracks, footprints, feces (coprolites) are all trace fossils, evidence that animals were here. With burrows, such as described here, the best science can only compare the fossil burrow with other known burrows to establish the species. Georgia has a rich record of trace fossils, but they’re focused in much later sediments, Cretaceous and younger.
Trace fossils are indirect, preserved evidence of past life. Burrows, tracks, footprints, feces (coprolites) are all trace fossils, evidence that animals were here. With burrows, such as described here, the best science can only compare the fossil burrow with other known burrows to establish the species. Georgia has a rich record of trace fossils, but they’re focused in much later sediments, Cretaceous and younger.
The Discoveries
The genus Palaeophycus trace fossils are defined as unbranched, cylindrical burrows, straight to sinuous, smooth walled, with variable diameter and typically structureless fill similar to host rock. Burrows naturally filled by sediments. What creature created the burrows is unknown, but in all likelihood was some type of worm. Further research in 2011 by James Shope on burrow morphology has tentatively classified these specimens as Palaeophycus heberti with one example of a different genus, Taenidium. The presence of Palaeophycus heberti along with Taenidium suggests an age of Cambrian or younger for the Pinelog Formation. The genus Taenidium ends with the Cambrian Period which closed 485 million years ago, so the burrows are at least that old.
The genus Palaeophycus trace fossils are defined as unbranched, cylindrical burrows, straight to sinuous, smooth walled, with variable diameter and typically structureless fill similar to host rock. Burrows naturally filled by sediments. What creature created the burrows is unknown, but in all likelihood was some type of worm. Further research in 2011 by James Shope on burrow morphology has tentatively classified these specimens as Palaeophycus heberti with one example of a different genus, Taenidium. The presence of Palaeophycus heberti along with Taenidium suggests an age of Cambrian or younger for the Pinelog Formation. The genus Taenidium ends with the Cambrian Period which closed 485 million years ago, so the burrows are at least that old.
Taenidium is an ichnogenus (trace fossil genus) present in Cambrian and younger rocks and is denoted primarily by meniscate structures, indicating the burrowing organism intentionally backfilled the burrow as it progressed. The burrow is defined as serpentine, unlined, unbranched with evenly spaced, uniformly thick backfill; distance between meniscae about equal or a little less than burrow width.
In 2011 James Brandon Shope, as one of Tony Martin’s students at Emory, reviewed and expanded the science in his unpublished Honors thesis. He was advised by Dr. Tony Martin. James Shope, who is now Dr. James Shope, is an environmental scientist at Rutgers (Website; Home - James Shope), in a 15/Dec/2025 email he warmly gave me permission to quote and borrow from his 2011 thesis. Shope identified the Taenidium from the 1996 fossils. He proceeded into the field to collect new samples.
Taenidium trace fossils are defined as serpentine, unlined, unbranched burrows with evenly spaced, uniformly thick, weakly arcuate and uniform meniscae backfill; distance between meniscae about equal or a little less than burrow width. Meniscae backfill means that the creature which created to burrow backfilled it as it went
Palaeophycus burrows were backfilled by nature. Taenidium burrows were backfilled by the burrowing animal as it progressed through the sediments.
The collection location is about 8 miles southwest of Jasper. Roughly 43 miles north of Atlanta. Their discovery made me edit my Georgia’s Fossil Map, suddenly Pickens County has Cambrian fossils in metamorphic rock! I’m always happy to add a new county as reporting fossils!
The collection location is about 8 miles southwest of Jasper. Roughly 43 miles north of Atlanta. Their discovery made me edit my Georgia’s Fossil Map, suddenly Pickens County has Cambrian fossils in metamorphic rock! I’m always happy to add a new county as reporting fossils!
Metamorphic Rock, Pickens County
Georgia Marble
Georghia’s most famous metamorphic rock is Georgia Marble which was once populated by a wealth of fossils. They were destroyed during its metamorphism. It began as a limestone completely made-up of the tiny calcium fossils of microscopic organisms which lived 600 million years ago. The original reef was a victim of the collision of North America into Gondwana more than 300 million years ago. The slow collision generated terrific pressure, which produced great heat. The terrain was buckled and folded, this heat and pressure metamorphized that limestone into Georgia Marble and recrystallization obliterated the fossils. Marble is a high garde metamorphic rock. Created by high pressure and temperatures. The quarry for Georgia Marble is also in Pickens County.
Georgia Marble
Georghia’s most famous metamorphic rock is Georgia Marble which was once populated by a wealth of fossils. They were destroyed during its metamorphism. It began as a limestone completely made-up of the tiny calcium fossils of microscopic organisms which lived 600 million years ago. The original reef was a victim of the collision of North America into Gondwana more than 300 million years ago. The slow collision generated terrific pressure, which produced great heat. The terrain was buckled and folded, this heat and pressure metamorphized that limestone into Georgia Marble and recrystallization obliterated the fossils. Marble is a high garde metamorphic rock. Created by high pressure and temperatures. The quarry for Georgia Marble is also in Pickens County.
The Pinelog Formation Quartzite
That same continental-collision event, heat, and pressure created the quartzite of Pickens County’s Pinelog Formation from the existing Cambrian Period sandstone which held the trace fossil burrows. But, for whatever reason, while the metamorphosis from sandstone to quartzite was complete, the conditions were not sufficient to destroy these ichnofossils (trace fossils). The Pinelog quartzite is considered low-grade metamorphic rock, meaning it formed in lower heat and pressures, this is why the fossils were preserved.
That same continental-collision event, heat, and pressure created the quartzite of Pickens County’s Pinelog Formation from the existing Cambrian Period sandstone which held the trace fossil burrows. But, for whatever reason, while the metamorphosis from sandstone to quartzite was complete, the conditions were not sufficient to destroy these ichnofossils (trace fossils). The Pinelog quartzite is considered low-grade metamorphic rock, meaning it formed in lower heat and pressures, this is why the fossils were preserved.
Both Georgia Marble and the Pinelog Quartzite are in Pickens County, Georgia. Henderson Mountain is about 10 miles due west of the Georgia Marble Plant. Why one was created in a low-pressure environment while the other was created in a high-pressure environment is unexplained to this author’s knowledge. However, as we’ll soon see they represent slightly different geologic provinces.
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Ask a Geology Professor
On my journey through Georgia’s natural history I frequently have questions I can’t answer. This was one; Why such a stark difference between The low grade Pinelog Formation and the high grade Georgia Marble when they’re in such close proximity? Dr. Burt Carter, Professor Emeritus at Georgia Southwestern, is my go-to guy. Burt’s smarter than I am. |
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On 20/Dec/2025 I emailed him.
Burt;
I admit to ignorance.
Both the trace fossil bearing, low-grade quartzite Pinelog Formation & the high-grade Georgia Marble occur in Pickens County. The Pinelog site is 10 miles nearly due-west of the Georgia Marble plant.
I assume both are the product of the North America/Gondwana collision.
Is there a simple explanation for the low/high grade difference when they're so geographically close? From what I read the difference between high & low grade metamorphic rock is the temperature and pressure.
Thomas
Burt;
I admit to ignorance.
Both the trace fossil bearing, low-grade quartzite Pinelog Formation & the high-grade Georgia Marble occur in Pickens County. The Pinelog site is 10 miles nearly due-west of the Georgia Marble plant.
I assume both are the product of the North America/Gondwana collision.
Is there a simple explanation for the low/high grade difference when they're so geographically close? From what I read the difference between high & low grade metamorphic rock is the temperature and pressure.
Thomas
Burt’s reply, also on 20/Dec/2025
Thomas
When a mountain chain forms, the compression shortens the crust significantly. One way to accomplish shortening is folding, like in a couple of the presentations I sent. (See Section 26, A-F, of this website) The folding takes originally flat layers and buckles some of their original width into upness and downness.
But there's a limit to how much this can accomplish. Eventually, if the compression continues, everything is up and down and the only remaining option is to break the rocks. Typically, maybe invariably, the rocks on a continent closer to the continent grinding into it are pushed up and over rocks closer to the center of the continent (the "craton").
So in the Appalachians (including the piedmont), rocks from farther east (towards Africa) were pushed westward (towards Kansas). The more easterly rocks were subjected to higher temp & pressure and so are higher grade rocks. They're pushed over the tops of lower grade rocks. After the mountains are eroded they lie side by side. Any place where, as you have observed, you get an abrupt change in grade is very likely a fault.
Go a little farther west and the Cartersville Fault system have pushed low grade metamorphic rocks of the Blue Ridge over completely unmetamorphosed rocks of the Valley and Ridge.
In general, in any metamorphic zone grade decreases away from the original continental suture. There are local hiccups where some rocks resist squeezing better than others, so their neighbors get squeezed worse, but it holds in general.
Major igneous intrusions are generally restricted to areas closer to the suture as well, for the same reason.
A few miles west of the Pinelog is unmetamorphosed Valley and Ridge Provincew sedimentary rock.
It was a damn good question Thomas. Thanks.
Burt
Thomas
When a mountain chain forms, the compression shortens the crust significantly. One way to accomplish shortening is folding, like in a couple of the presentations I sent. (See Section 26, A-F, of this website) The folding takes originally flat layers and buckles some of their original width into upness and downness.
But there's a limit to how much this can accomplish. Eventually, if the compression continues, everything is up and down and the only remaining option is to break the rocks. Typically, maybe invariably, the rocks on a continent closer to the continent grinding into it are pushed up and over rocks closer to the center of the continent (the "craton").
So in the Appalachians (including the piedmont), rocks from farther east (towards Africa) were pushed westward (towards Kansas). The more easterly rocks were subjected to higher temp & pressure and so are higher grade rocks. They're pushed over the tops of lower grade rocks. After the mountains are eroded they lie side by side. Any place where, as you have observed, you get an abrupt change in grade is very likely a fault.
Go a little farther west and the Cartersville Fault system have pushed low grade metamorphic rocks of the Blue Ridge over completely unmetamorphosed rocks of the Valley and Ridge.
In general, in any metamorphic zone grade decreases away from the original continental suture. There are local hiccups where some rocks resist squeezing better than others, so their neighbors get squeezed worse, but it holds in general.
Major igneous intrusions are generally restricted to areas closer to the suture as well, for the same reason.
A few miles west of the Pinelog is unmetamorphosed Valley and Ridge Provincew sedimentary rock.
It was a damn good question Thomas. Thanks.
Burt
Thanks Burt, the universe knows I’ve certainly had some not-so-great questions!
Burt is right to mentin the fossil rich sedimentary deposits of Northwest Georgia's Ridge and Valley Province. These were in place when North Amercia and Gondwana collided, in many cases they were folded and buckled, but they were not metamorphisized. They did not expereince the heat and pressure.
Why northwest Georgia was spared metamorphisis but north central Geogias was not, is an interesting question.
Burt is right to mentin the fossil rich sedimentary deposits of Northwest Georgia's Ridge and Valley Province. These were in place when North Amercia and Gondwana collided, in many cases they were folded and buckled, but they were not metamorphisized. They did not expereince the heat and pressure.
Why northwest Georgia was spared metamorphisis but north central Geogias was not, is an interesting question.
Worth a look
In the introduction of 1996 paper by Martin and Crawford the scientists state “… because trace fossils commonly originate as biogenic structures, hence low-grade metasedimentary rocks that contain physical sedimentary structures may also contain trace fossils.” The implied lesson is too keep an open mind when exploring low-grade metamorphic rock. It is entirely possible that there are more metamorphic fossils out there.
In the introduction of 1996 paper by Martin and Crawford the scientists state “… because trace fossils commonly originate as biogenic structures, hence low-grade metasedimentary rocks that contain physical sedimentary structures may also contain trace fossils.” The implied lesson is too keep an open mind when exploring low-grade metamorphic rock. It is entirely possible that there are more metamorphic fossils out there.
The Scientists
Dr. Anthony (Tony) Martin is an active paleontologist & geologist specializing in trace fossils (Ichnofossils) and a Professor at Emory University, he’s taught there since the early 1990s. He was kind enough to answer my questions and provide the reports and contacts to assemble this page.
Dr. Anthony (Tony) Martin is an active paleontologist & geologist specializing in trace fossils (Ichnofossils) and a Professor at Emory University, he’s taught there since the early 1990s. He was kind enough to answer my questions and provide the reports and contacts to assemble this page.
In their 1996 paper, Martin and Crawford placed Pickens County as straddling the Piedmont-Blue Ridge Geologic Provinces. On 10/December/2025 I had the following email from Tony Martin…
Thanks for reaching out about the Blue Ridge trace fossils. They were indeed trace fossils, interpreted as burrows in a metaquartzite that was originally a cross-bedded quartz sandstone…. So yes, there are trace fossils from the Blue Ridge, and they indicate the original sedimentary rocks were probably Lower Paleozoic quartz sandstones. I remember John Costello and Mike Higgins had a friendly argument over the age of the sedimentary rocks, where Mike thought they were Paleozoic but John thought they were Proterozoic. But the trace fossils pretty much cinched that they were Paleozoic. It was pretty cool to apply paleontology to a structural-geology-mapping problem!
Thanks for reaching out about the Blue Ridge trace fossils. They were indeed trace fossils, interpreted as burrows in a metaquartzite that was originally a cross-bedded quartz sandstone…. So yes, there are trace fossils from the Blue Ridge, and they indicate the original sedimentary rocks were probably Lower Paleozoic quartz sandstones. I remember John Costello and Mike Higgins had a friendly argument over the age of the sedimentary rocks, where Mike thought they were Paleozoic but John thought they were Proterozoic. But the trace fossils pretty much cinched that they were Paleozoic. It was pretty cool to apply paleontology to a structural-geology-mapping problem!
In 2011 Shope explains; Crawford found that graphitic phyllites within the quartzite resemble layers in the Nantahala Formation of the Chilhowee Group, and that the Pinelog is nearly identical to sequences found on Chilhowee Mountain, Tennessee. The Lower Chilhowee Group stratigraphically overlies the Ocoee Group and is a continental to marine-shelf clastic sequence. The Chilhowee marks the continental rifting of Pannotia (A short-lived Precambrian supercontinent) that later formed Laurentia, Baltica, Siberia, and Gondwana, showing the transition from an actively rifting margin of Laurentia to a passive margin as the Iapetus Ocean widened. The Ocoee Group is primarily composed of clastic sediments and interpreted to have formed within a rifting basin along the southern margin of Laurentia.
Trace Fossil Descriptions, Shope 2011 (lightly edited)
The ichnogenus Palaeophycus has been misused for a number of years and includes some 54 ichnospecies. In many cases, each individual discovery of Palaeophycus between 1847 and 1883 was afforded its own ichnospecies instead of being properly described and placed into a pre-existing ichnospecies. Because of the confusion created by the multiple ichnospecies, Pemberton and Frey only recognized five different ichnospecies of Palaeophycus based on wall linings and burrow sculptings. These are P. heberti, P. tubularis, P. striatus, P. sulcatus, and P. alternatus.
The ichnogenus Palaeophycus has been misused for a number of years and includes some 54 ichnospecies. In many cases, each individual discovery of Palaeophycus between 1847 and 1883 was afforded its own ichnospecies instead of being properly described and placed into a pre-existing ichnospecies. Because of the confusion created by the multiple ichnospecies, Pemberton and Frey only recognized five different ichnospecies of Palaeophycus based on wall linings and burrow sculptings. These are P. heberti, P. tubularis, P. striatus, P. sulcatus, and P. alternatus.
Palaeophycus burrows are generally lined by agglutinated (firmly assembled) sediment that can be either thin or thick. The shapes of the burrows themselves are cylindrical, rarely branch, and can be straight to slightly curved; burrow walls are unornamented and smooth. There are limited reports of Palaeophycus in Ediacaran rock, thus Palaeophycus can be used as a limited index fossil for Cambrian and younger rocks, albeit with caution.
To test the 1996 findings of Martin and Crawford, the reexamined burrows will be compared with other trace fossils reported near the Blue Ridge Province of Georgia. Trace fossils have been described in the Carolina Slate Belt from the late Precambrian, which extends from east-central Georgia up through South Carolina, North Carolina, and into southeast Virginia. The belt has been deformed by metamorphic and igneous activity, thus many of the physical structures have been lost or deformed themselves. Unverified early reports cite the existence of fossil structures resembling burrows in the slate, whereas later reports cite the presence Ediacaran body fossils.
While somewhat problematic to readily identify, a potential candidate for the Carolina Slate Belt burrows could be Skolithos. Skolithos is an ichnogenus that is normally interpreted as dwelling burrows of annelids or phoronids. Annelids compose a large phylum of segmented worms, and phoronids are the relatively small phylum of horseshoe worms, both of which are common throughout the world’s oceans.
Skolithos most commonly occurs in arenaceous rocks of the lower Paleozoic and younger, especially in the Cambrian to Devonian. These burrows may be densely crowded, but also occur isolated or in less densely populated groups. The length of the burrow can also be affected by the scouring of the overlying sediments, which may shorten the preserved burrow. The diameter of Skolithos burrows range from 1-15 mm. Martin and Crawford’s description of Palaeophycus at Henderson Mountain does not exclude the potential of the burrows to be Skolithos, thus these should be compared to descriptions of that ichnogenus as well.
Methods (Shope 2011 edited)
Two sampling locations were selected along Henderson Mountain, Pickens County, Georgia, along the roads of Mulberry Circle and Oak Trace. These areas were selected based on the proximity to the reported 1996 locations of Palaeophycus by Martin and Crawford and the presence of outcrops. The area had been previously cleared for development and the underlying rocks exposed and displaced. Since clearing, development of the area has mostly subsided and now hosts a forest of new-growth pine trees.
Two sampling locations were selected along Henderson Mountain, Pickens County, Georgia, along the roads of Mulberry Circle and Oak Trace. These areas were selected based on the proximity to the reported 1996 locations of Palaeophycus by Martin and Crawford and the presence of outcrops. The area had been previously cleared for development and the underlying rocks exposed and displaced. Since clearing, development of the area has mostly subsided and now hosts a forest of new-growth pine trees.
Twenty-seven rock samples were collected and the location of each sample was recorded using a GPS unit. Samples were selected based on the presence of bedding, cross-bedding, suspected burrows, or dark spots.
The color of the fractured surface of each sample was recorded using a rock-color chart issued by the Geological Society of America (GSA). Samples were described as sedimentary rocks instead of metamorphic, seeing that the metamorphic grade was low enough to preserve physical sedimentary structures.
Additionally, Shope carefully re-measured the trace fossil burrows, from 1996 and 2011, and their dimensions recorded, the average diameter was 5.75 mm (.22”).
Additionally, Shope carefully re-measured the trace fossil burrows, from 1996 and 2011, and their dimensions recorded, the average diameter was 5.75 mm (.22”).
Pinelog Formation
The Pinelog Formation, previously regarded as un-fossiliferous, consists of quartzite and meta-conglomerates (about 75 to 85%) and graphitic phyllites C15 to 20%), and has been considered to belong to either the Late Proterozoic Era (1 billion to 538.8 million years ago) or Early Paleozoic Era Cambrian Period. (Shope 2011) The formation has an apparent thickness of up to a kilometer in some locations; however, this has likely been multiplied by thrust faulting. The quartzite in the Pinelog has well-preserved trough cross-beds and probably flaser bedding in places. The trace fossils occur in a relatively thin zone of the cross bedded quartzite within a thick sequence of the quartzite and meta-conglomerate.
In their 1996 report Martin and Crawford noted that “Neither body nor trace fossils have been reported from the Piedmont-Blue Ridge Province of Georgia, although examples have been reported from metasedimentary rocks in areas further north and east in the Appalachians…”
The Pinelog Formation, previously regarded as un-fossiliferous, consists of quartzite and meta-conglomerates (about 75 to 85%) and graphitic phyllites C15 to 20%), and has been considered to belong to either the Late Proterozoic Era (1 billion to 538.8 million years ago) or Early Paleozoic Era Cambrian Period. (Shope 2011) The formation has an apparent thickness of up to a kilometer in some locations; however, this has likely been multiplied by thrust faulting. The quartzite in the Pinelog has well-preserved trough cross-beds and probably flaser bedding in places. The trace fossils occur in a relatively thin zone of the cross bedded quartzite within a thick sequence of the quartzite and meta-conglomerate.
In their 1996 report Martin and Crawford noted that “Neither body nor trace fossils have been reported from the Piedmont-Blue Ridge Province of Georgia, although examples have been reported from metasedimentary rocks in areas further north and east in the Appalachians…”
Note, in 1974 Dr. Michael Voorhies from UGA reported a wealth of Pleistocene body fossils from the sand beds of Kettle Creek in southwest Wilkes County on the Piedmont between Athens and Augusta. (See Section 20I of this website.)
As mentioned earlier, Martin and Crawford refer to the Piedmont-Blue Ridge Province in their report. These are two separate Georgia geologic provinces, The Piedmont Province and the Blue Ridge Province. There seems to be some debate over northwest Georgia’s Provinces a seen in these various maps.
If we look at the 1976 Physiographic Map, it shows 4 distinct provinces present in Pickens County. These are the scars from the collision of North America and Gondwana 300 million years ago.
- Blue Ridge Mountains District (BRM)
- A mass of rugged mountains and ridges ranging in elevation from 3500-4700 feet in the north and east to 3000-3500 feet in the southwest is the dominant topographic feature of the Blue Ridge Mountain District. Differing rates of erosion upon the Great Smoky Group by the headwater tributary streams, that eventually drain to either the Atlantic Ocean or the Gulf of Mexico, have produced valleys that are 1500-2000 feet below the adjacent summits. The southern boundary of the Blue Ridge abuts the Piedmont Province at approximately the 1700 foot elevation where a sharp change in regional slope occurs.
- Cherokee Upland District (ChU)
- The northern portion of the Cherokee Upland District is a rough, hilly surface with elevations ranging from 1300-1500 feet. Except for a few isolated mountains. elevation gradually decreases to 1000 feet in the southern part. The westward-flowing streams in the northern area occupy deep, narrow valleys 300-600 feet below the adjacent ridges. The eastern and southern boundaries are formed by the low, linear, parallel ridges of the Hightower-Jasper Ridges District.
- Hightower-Jasper Ridges District (HJR)
- Although Hightower Ridges and Jasper Ridges have different structural and lithologic histories, they are topographically so similar that they must be discussed together. The Hightower-Jasper Ridges District consists of a series of low, linear, parallel ridges separated by narrow valleys. The Hightower Ridges range in elevations from 1500 feet in the northeast to 1000 feet on the southwest. Relief in this area varies from 500 feet in the northeast to 200 feet in the southwest. The Jasper Ridges bisect the McCaysville Basin District and continue southward as allow area between the Cohutta and Blue Ridge Mountains. These ridges range in elevation from 2400 feet in the north to 1200 feet near Canton where they join the Hightower Ridges. Relief varies from 800 feet in the north to 200 feet near Lake Allatoona. Some structural control of streams in the district is exhibited by the modified rectangular drainage patterns. The southern and western boundaries are located where there is a decrease in the density of the linear ridges.
- Dahlonega Upland District (DU)
- The rough and hilly northeastern part of the Dahlonega Upland District stands 1500-1700 feet above sea level. Streams in the area flow south out of the Blue Ridge Mountains District, and have cut deep, narrow valleys 500-600 feet below the surrounding surface. In the southern and southwestern portions, surface elevations decrease to 1200 feet. Stream valleys are wider, more open, and only 200-300 feet below the adjacent surface. The southern and western boundaries are formed by the low linear, parallel ridges of the Hightower-Jasper Ridges District.
Shope’s map places Henderson Mountain in the southwest corner of Perkins County which is the Cherokee Upland District. According to Google Earth the worn peak of Henderson Mountain stands at about 1,900 feet (579 meters) and his collection sites are along the western flanks.
As way of note the largest, historic Georgia Marble Plant & quarry is about 2 miles north of Nelson Georgia and firmly in the Dahlonega Upland District.
Shope’s 2011 Description of the Pinelog Formation
The Pinelog Formation is a basal sequence of metasedimentary rocks that overlie basement rock in the Southern Appalachians. The Pinelog is divided into three separate subunits - Lower, Middle, and Upper… Then Shope explains that the focus of his research was on the trace fossils of the Middle Pinelog Formation.
The Pinelog Formation is a basal sequence of metasedimentary rocks that overlie basement rock in the Southern Appalachians. The Pinelog is divided into three separate subunits - Lower, Middle, and Upper… Then Shope explains that the focus of his research was on the trace fossils of the Middle Pinelog Formation.
The Middle Pinelog is an approximately 100-m thick sequence consisting mainly of light-yellow to light-grey, thinly bedded, trough cross-bedded quartzite that range from subarkosic to quartz arenite in the original source rock, or protolith (Li and Tull 1998). These layers grade downward into less mature, coarser metagraywackes and metaconglomerates that compose the Lower Pinelog.
In general, grains are recrystallized, and intermittent relict primary grains indicate the grain size was initially fine to medium sand. The sequence then grades up into the quartz-mica phyllite/schist and the mica phyllite/schist of the Upper Pinelog (Li and Tull 1998). The transition from the coarser grains of the Lower Pinelog into the finer grains of the middle Pinelog has been interpreted as a transgressive sequence.
In this scenario, sediments of the Lower Pinelog were deposited in a fluvial to alluvial fan environment, which were overlain by fine-grained sediments of a shallow-marine environment (Tull 2007). Li and Tull (1998) interpreted these Pinelog sequences as a result of deposition in a basin along the rifting Laurentian continental margin that was subsequently stabilized and inundated.
In general, grains are recrystallized, and intermittent relict primary grains indicate the grain size was initially fine to medium sand. The sequence then grades up into the quartz-mica phyllite/schist and the mica phyllite/schist of the Upper Pinelog (Li and Tull 1998). The transition from the coarser grains of the Lower Pinelog into the finer grains of the middle Pinelog has been interpreted as a transgressive sequence.
In this scenario, sediments of the Lower Pinelog were deposited in a fluvial to alluvial fan environment, which were overlain by fine-grained sediments of a shallow-marine environment (Tull 2007). Li and Tull (1998) interpreted these Pinelog sequences as a result of deposition in a basin along the rifting Laurentian continental margin that was subsequently stabilized and inundated.
Thanks owed!
Many thanks to Dr. Tony Martin for sharing his initial discovery and the reports it generated, this is solid, exploratory science. He found fossils where fossils weren’t supposed to be, collected samples and reported them.
Thanks to Dr. James Shope for usage permission to his 2011 report and the solid science that report represents.
Special thanks, as always, to Dr. Burt Carter, Professor Emeritus at Georgia Southwestern, for alerting me to this history and assisting in gathering the related reports. In 1996 Dr. Burt Carter was the President of the Georgia Geological Society, Tony Martin’s original report was published in the society’s 31st Annual Field Trip Report, which was edited by Randy Kath.
Many thanks to Dr. Tony Martin for sharing his initial discovery and the reports it generated, this is solid, exploratory science. He found fossils where fossils weren’t supposed to be, collected samples and reported them.
Thanks to Dr. James Shope for usage permission to his 2011 report and the solid science that report represents.
Special thanks, as always, to Dr. Burt Carter, Professor Emeritus at Georgia Southwestern, for alerting me to this history and assisting in gathering the related reports. In 1996 Dr. Burt Carter was the President of the Georgia Geological Society, Tony Martin’s original report was published in the society’s 31st Annual Field Trip Report, which was edited by Randy Kath.
Explorers verses Adventurers
Fossil collectors can be both Adventurers and Explorers. Study the literature, then head into the field and explore, but as you explore keep in mind that there is a line between an explorer and an adventurer.
You’ll see that there are frequent discrepancies between the literature and the realities in the field; unreported fossils, errors in past observations, unreported locations, surprise finds like these trace fossils in metamorphic rock...
Explorers observe the differences and report them back so that others might follow and build upon their work. Adventurers give no information back to the community; and in many cases they hoard information for personal gain.
Science is a journey, not a destination. Science only progresses when knowledge is shared.
Fossil collectors can be both Adventurers and Explorers. Study the literature, then head into the field and explore, but as you explore keep in mind that there is a line between an explorer and an adventurer.
You’ll see that there are frequent discrepancies between the literature and the realities in the field; unreported fossils, errors in past observations, unreported locations, surprise finds like these trace fossils in metamorphic rock...
Explorers observe the differences and report them back so that others might follow and build upon their work. Adventurers give no information back to the community; and in many cases they hoard information for personal gain.
Science is a journey, not a destination. Science only progresses when knowledge is shared.
The reviewed papers are available for download below.
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References
- Martin, Anthony J., Crawford, Ralph F; Trace Fossils in the Pinelog Formation, Piedmont-Blue Ridge, Georgia, and Their Application to Sedimentology, Stratigraphy, and Structural Geology, Georgia Geological Society Guidebook, Volume 16, Pages 89-96, 1996
- Kath, Randy L. (Editor); The Cartersville Fault Problem: Revisited; 30th Anniversary Field trip, 31st Annual Field Trip, Georgia Geological Society Guidebooks, Vol. 16, Number 1, November 1996
- Shope, James Brandon; Ichnology and Composition of the Pinelog Formation Quartzite, Jasper, Georgia: Situating the Formation in the Geologic Record. Bachelor of Sciences with Honors Thesis, Emory University College of Arts and Sciences, Department of Environmental Studies, Advised by Anthony J. Martin PhD., 18/April, 2011 (Downloadable from Emory University)
- How Georgia Marble Was Formed (Georgia Marble Company - Polycor Inc.)