User:IveGoneAway/sandbox/Abilene conglomerate
| Abilene conglomerate | |
|---|---|
| Stratigraphic range: | |
 Abilene conglomerate outcrop at the type location above Turkey Creek across the Smoky Hill River from Abilene, Kansas  | |
| Type | Geologic bed |
| Underlies | Later Pleistocene glacial loess or dunes |
| Overlies | Eroded slopes of Wellington Shale (most commonly) |
| Lithology | |
| Primary | Calcareous conglomerate of sand and gravel |
| Other | Diagnostic pebbles and cobbles of sandstone and mudstone from the Dakota Formation, chalk from the Greenhorn Formation, and distinctive scattered quartz and quartzite presumed from the Rocky Mountains |
| Location | |
| Coordinates | 38°52′20″N 97°11′40″W / 38.87232°N 97.19456°W |
| Region |  Kansas |
| Country |  United States |
| Type section | |
| Named for | Abilene, Kansas[1] |
| Named by | C.S. Prosser[2] |
| Location | Turkey Creek, Dickinson County, Kansas[3] |
| Year defined | 1895 |
| Coordinates | 38°52′20″N 97°11′40″W / 38.87232°N 97.19456°W |
The Abilene conglomerate is an informal Pleistocene unit of sand and gravel "cemented by calcarous matter".[4] Here and there are redish sandstone and yellowish chalk cobbles. Outcrops of this mortar bed are found along tributaries of the Smoky Hill River in the vicinity of Abilene and Solomon, Kansas. Pioneering geologists, including F.B. Meek, F.V. Hayden,[4] E. Haworth,[3] C.S. Prosser,[2] and R.C. Moore [5] each reported on the unusual nature of the conglomerate. At that time, each identified or accepted that the unit formed in the Permian, like all of the shale and limestone in the surrounding hills. In particular, Meek and Hayden observed that the unusual conglomerate bed appeared to lie just at the top of the beds of rich Permian marine fossils and repetative massive limestone beds but also just at the base of similar shale that had no fossils or massive limestones (such as they could recognise then). Later geologists would determine that this change in the rock patterns marked the very last of the open marine cycles and the beginning of salt lake sequences.
Moore eventually recognized that the conglomerate was much more recent than the Permian bedrock, inferring that the conglomerate formed only after the Kansas River and Smoky Hill River finished cutting down through all of the Permian layers found in Kansas (between Saline and Riley counties, all of the Kansas Permian is exposed.
Today, this conglomerate bed is thought to be possibly related to the lower, cemented conglomerate found within the McPherson Equus Beds to the southwest.[6][7]
Some geologist attempted to label the unit as Abilene limestone, in part to reflect the calcareous nature of the outcrop at Abilene, but also to explain how they thought that the conglomerate they could find only in valley side was weathered Permian Hollenberg dolomite.[8]
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Exploration[edit]
Permian conjecture[edit]
From the middle of the 19th century, geologists recognised that the Kansas River valley, including its upper forks into the Smoky Hills and the High Plains, held excellent exposures of full sequences of the Pennsylvanian, Permian, Late Cretaceous, Neogene, and Quaternary systems. In early exploration of the Permian sequences, a thick bed of calcarous, cemented sand and gravel was encounted in the terraces of the tributaries of the Smoky Hill River near a new stage coach stop then named Mud Creek.
Braving Border ruffians, Bushwhackers, and Jayhawkers as well as battles between the Plains and settler Indian nations,[11]Cite error: A <ref> tag is missing the closing </ref> (see the help page).[12][13]
F.B. Meek and F.V. Hayden were the first to scientifically study the valley's geology and the first to describe the conglomerate. Expecting the rock outcrops along that river to continue showing a rising Permian sequence, Meek and Hayden placed the conglomerate they found at Turkey Creek[3] within the Permian Period in their 1859 report.[4]
Meek and Hayden observed that the bold conglomerate outcrop looked to be a marker unit. Even though the shales above and below the conglomerate are similar in color and texture, these early geologist saw other very distinct changes. While marine fossils and limestones are abundant below the conglomerate, none are seen in the shale above the conglomerate. While the shales below the conglomerate feature thousands of feet of famous limestone cyclothems, this pattern abruptly stops at and above the conglomerate.[14]
The explorers didn't encounter marine limestone again until they reached the Greenhorn Formation over the Dakota Sandstone high up into the Smoky Hills.
In reality, Meek and Hayden's "No. 10" (the Wellington shale) records a sudden transition from the preceding open marine sequences to the following lacustrine sequences; rather than holding no fossils, the following sequences hold incredible insect fossils. (For further discussion, see Wellington Formation).
Meek and Hayden's incorrect placement of the conglomerate over the shale just above the Herington Limestone caused later geologists to name as a separate unit what in reality was the lowest beds of the Wellington Shale. One such geologist was C. S. Prosser.
In 1895, C. S. Prosser published his classification of the conglomerate, naming it for the famous cow town that had grown on the Mud Creek site. Trying to map the Abilene unit as a limestone, Prosser followed a real Permian dolomite bed that actually runs out from "behind" the Pleistocene terrace at Abilene, tracing that dolomite all the way to Herington and Marion. Prosser then defined a Permian unit he named Marion Formation, and designated the top member of that formation as the Abeline conglomerate, the "underlying" shale he named Pearl Shale and included the known Herington Limestone below that.[2][15][16]
The dolomitic Hollenberg Limestone marker bed was then recognized within the Pearl Shale.[17]
These beds of "Abilene" dolomite were of interest to oil drillers as useful markers for drillers playing for the lower known producing beds, but they were also of interest for potential oil production further west. Some argued that the prominent dolomite bed was the true type of the Abilene, and that unit should be reclassified as Abilene Limestone while the conglomerate near Abilene at Solomon were merely reformings of weathered dolomite.[18]
Age Prosser's Classifications Present Classifications Formation Member Member Formation Pleistocene Abilene conglomerate McPherson Equus Beds Permian Wellington Shale (upper shales) Wellington Shale Hutchinson Salt (gypsum beds) Marion limestone
[19][20]Abilene conglomerate Hollenberg Limestone Pearl shale (marine shale) Herington limestone Herington Limestone Nolans Limestone Enterprise shale Paddock Shale Krider Limestone Odell Shale Luta limestone Cresswell Limestone Winfield Limestone
Effectively, the Marion and Pearl classifications were inventions to accommodate the mistaken interpretation of the Abilene conglomerate as Permian deposits rather than Pleistocene valley infill. Today, the Marion classification is replaced by the Nolans Limestone and the Odell Shale, and the old Pearl Shale is now recognised as the lowest beds of the Wellington Shale.
Pleistocene evidence[edit]
Several lines of evidence suggested that the conglomerate bed was later, if not much later, than the Permian Period.
- No outcrop was found where Wellington Shale was lying in contact over the conglomerate.
- There was no sign from well logs within the Kansas valley that the conglomerate carried on into the strata buried below the Wellington Formation, demonstrating that the deposits actually came from a partial refilling of the valley some time after the present valley was cut.
- The inclusion of reddish pebbles and cobbles of Dakota sandstone and mudstone and yellowish Greenhorn chalks made it clear that the sand and gravel were carried from the Creteceous outcrop of the Smoky Hills to the west well after the closure of the Western Interior Seaway and the Neogene uplift of the Colorado plains.
- The distinctive presence of larger quartz and quarzite pebbles[4] suggests material from the weathering of the Paleogene Rocky Mountains, or later weathering of the Ogallala Formation.
- Finally, fossils in the conglomerate are relatively recent and the conglomerate is considered similar to the conglomerate bed at the base of the McPherson Equus Beds, so named for the appearance of modern horse fossils.
Lithology[edit]
Developmment[edit]
The downcutting of Permian and Pennsylvanian formations to form the Kansas and Smoky Hill river valleys largely did not develop until the deposition of the Ogallala, the lowest bed of the Ogallala only found broad, shallow valleys to fill.
calcite-rich brine
For some time after the sand and gravel were deposited, either a stable and shallow water table was maintained for a time within the Kansas River, such that a deep caliche was formed under the surface, particularly away from the river flow.
Gallery[edit]
-
Outcrop above Turkey Creek -
Outcrop above Turkey Creek -
Outcrop above Turkey Creek -
Landscape boulders in Abilene -
Dakota and Greenhorn cobbles in the landscape boulder -
Natural pavement in an equipment yard -
A quartz eratic as noted by Meek and Hadyen -
Appearance of caliche at the base of the outcrop.
Further reading[edit]
- 1859 : F.B. Meek and F.V. Hayden. "Geological Explorations in Kansas Territory" (PDF). Proceedings of the Academy of Natural Sciences of Philadelphia. IX (9). Academy of Natural Sciences of Drexel University. Retrieved 2023-04-08.
- 1895: Prosser, C.S., The classification of the upper Paleozoic rocks of central Kansas: Journal of Geology, v. 3, nos. 6–7, p. 682-705, 764–800.
- 1897: Erasmus Haworth and J. W. Beede. "The McPherson Equus Beds". Geological Survey of Kansas. Vol. 2. Retrieved 2023-04-07.
- 1917: Raymond Cecil Moore and Winthrop P. Haynes. "Oil and Gas Resources of Kansas". Kansas Geological Survey (Bulletin 3). University of Kansas Publications, State Geological Survey of Kansas: General Stratigraphy of Kansas. Retrieved 2023-04-08.
References[edit]
- ^ "Geologic Unit: Abilene". National Geologic Database. Geolex — Significant Publications. United States Geological Survey. Retrieved 2023-04-05.
- ^ a b c Prosser, C.S., 1895, The classification of the upper Paleozoic rocks of central Kansas: Journal of Geology, v. 3, nos. 6-7, p. 682-705, 764-800.
- ^ a b c Erasmus Haworth and J. W. Beede (1897). "The McPherson Equus Beds". Geological Survey of Kansas. Vol. 2. Retrieved 2023-04-07.
... From the buff limestones and shales in a small quarry on the south bank of the Smoky Hill river, south of Abilene and not much below a conglomerate exposed along Turkey creek which was first described by Meek and Hayden in 1859 ..., the writer [Haworth] collected the following species ... ....
- ^ a b c d F.B. Meek and F.V. Hayden (1859). "Geological Explorations in Kansas Territory" (PDF). Proceedings of the Academy of Natural Sciences of Philadelphia. IX (9). Academy of Natural Sciences of Drexel University: 16. Retrieved 2023-04-08.
9. Rough conglomerated mass, composed fragments [of] magnesium limestone and sandstone, with sometimes a few quartz pebbles, cemented by calcarous matter; ... Locality, south side Smoky Hill river, 10 or 12 miles below Solomon's Fork
- ^ Raymond Cecil Moore and Winthrop P. Haynes (1917). "Oil and Gas Resources of Kansas". Kansas Geological Survey (Bulletin 3). University of Kansas Publications, State Geological Survey of Kansas: General Stratigraphy of Kansas. Retrieved 2023-04-08.
Abilene conglomerate member. (Prosser, 1895a, p. 682-705, 764-800; named from Abilene, Dickinson county, Kansas.) At the top of the Marion formation is an irregular, somewhat conglomeratic limestone division defined by Prosser from typical exposures, first described by Meek and Hayden ... In the vicinity of Herington and Marion it is represented, according to Beede (1908, p. 256), by "heavy, hard, perhaps dolomitic stone, composed of fragments of yellow, orange and gray masses firmly united in a light gray cementing material." It forms a weak escarpment, which has been followed by Beede to a point south of Marion. It appears to have sufficient continuity to be mapped over a larger area.
Note: At the general level that Moore would expect the Abiliene conglomerate in the region of Herington and Marion is found the Hollenberg Limestone, which is a dolomite bed that does form a weak bench that is traceable throughout those counties. - ^ "Geologic Unit: McPherson". National Geologic Database. Geolex — Significant Publications. United States Geological Survey. Retrieved 2023-04-07.
Locally, conglomeratic bed 1 to 6 feet thick occurs at base formation; material in this conglomerate is similar to materials comprising so-called Abilene conglomerate.
- ^ Charles C. Williams and Stanley W. Lohman (1949). "Geology and Ground-water Resources of a Part of South-central Kansas with special reference to the Wichita municipal water supply". Kansas Geological Survey (Bulletin 79). University of Kansas Publications, State Geological Survey of Kansas: https://www.kgs.ku.edu/Publications/Bulletins/79/07_geoquat.html. Retrieved 2023-04-08.
Locally a conglomeratic bed occurs at the base of the older part of the McPherson formation. It ranges from 1 to 6 feet in thickness and is composed of shale, quartz, and sandstone pebbles in varying proportions, cemented with impure calcium carbonate. ... The material in the conglomerate is similar to materials comprising the so-called Abilene conglomerate, ...
- ^ Raymond C. Moore (February 1920). "Petroleum Resources of Kansas". Mining and Metallurgy. 158. American Institute of Mining and Metallurgical Engineers.
{{cite journal}}:|section=ignored (help) Here, Moore labels the Abilene as a limestone rather than a conglomerate. - ^ J. W. Beede (1908). "Formations of the Marion Stage of the Kansas Permian". Kansas Academy of Science: 242–256. Retrieved 2023-04-10.
The name, "Abilene conglomerate," was first applied a a formation name by Prosser in "The classification of the "Upper Palæozoic Rocks of Kansas." It is a calcareous conglomerate, containing some some same and sandstone pebbles, near Abilene, where it seems to be considerably thicker than the Herington-Marion region. In the field, no sand or sandstone was noted in the rock about Herington or Marion. It [the Herington-Marion stone] is a hard, heavy, perhaps dolomitic stone, composed of of fragments of yellow, orange, and grey masses firmly united in a light-gray cementing material. As previously noted, it rests upon the "cracked shale," which is rather thick in appearance in places and frequently not very disimilar in appearance in poor exposures.
Note: The text does go on to discuss how the alleged Abilene and Pearl at Herington-Marion more resemble the Wellington shales than they resemble any sort of river sediment. - ^ Raymond C. Moore (1920). "Oil and Gas Resources of Kansas, Part II, Geology of Kansas". Kansas Geological Survey (Bulletin 6 Part II). University of Kansas Publications, State Geological Survey of Kansas: Permian System. Retrieved 2023-04-08.
Pearl shale member [Named from Pearl, Dickinson County, Kansas (Sellards and Beede, 1905, p. 225).] A succession of green, blue and reddish shale, termed the Pearl shale member, overlies the Herington limestone. On account of lack of resistance of the overlying beds, outcrops of the Pearl shale are very uncommon. The thickness of the member is estimated to be 70 feet. In the upper portion of the Pearl shale there are more or less persistent beds of limestone. These are the uppermost calcareous deposits of importance in the Permian of Kansas and mark the line of division between the Marion and the succeeding Wellington formation. [Note: It appears that the so-called Abilene conglomerate, which has previously been referred to the uppermost part of the Marion formation, is in reality a Tertiary deposit. It contains fragments of rock which apparently belong to the Dakota sandstone and at no point has it been observed in a stratigraphic position beneath the Wellington shale.]
Note: Moore now excludes the Abilene c. from the Marion, but is not quite ready to merge the Pearl Sh. with the Wellington Sh., and discusses limestones that will evenually be named the Hollenberg Ls marker bed. - ^ 1831: The Delaware destroyed the Capital of the Republican Pawnee. — William E. Connelley (1918). A Standard History of Kansas and Kansans. Vol. 1. Chicago, IL: Lewis Publishing Company. pp. 248–249.
- ^ 1850: Pottawatomie defeated Pawnee at Chapman Creek. "Potawatomi Tribal History including the Potawatomi of the Prairie". The Digital Research Library Illinois History Journal.
- ^ 1857: Kaw, Delaware, and Pottawatomie defeated Cheyenne at Dry Creek
- ^ F.B. Meek and F.V. Hayden (1859). "Geological Explorations in Kansas Territory" (PDF). Proceedings of the Academy of Natural Sciences of Philadelphia. IX (9). Academy of Natural Sciences of Drexel University: 16. Retrieved 2023-04-08.
The apparent absence of fossils in the beds above No. 10, renders it impossible, with our present information, to determine with certainty the upper limits of the series containing Permian forms. It is true, there is at places a kind of conglomerated mass, occupying the horizon No. 9, which might appear to form a natural line of division between the beds containing the Permian fossils, and those above, in which we fouud no organic remains ; but this seems to be local, and although there is a new feature presented by the zone of gypsum deposits above it, we find between the beds and layers of gypsum, and far above the horizon at which they occur, bluish, greenish, and other colored clays, not only similar to those between the beds and layers of limestone containing the Permian fossils in division No. 10, but also precisely like the laminated clays between the beds of limestone of the upper Carboniferous series far below. Again, in these clays of the gypsum zone, as well as through a considerable thickness of clays above it, there are occasional seams of clay-stone, which sometimes pass iato seams of magnesian limestone, exactly like some of those containing Permian fossils, in division No. 10. We saw no fossils in these seams amongst the gypsum bearing beds, nor higher in the series, but it is probable they may yet be found in some of the more calcareous portions
- ^ Cite error: The named reference
Latta49was invoked but never defined (see the help page). - ^ "Geologic Unit: Marion". National Geologic Database. Geolex — Significant Publications. United States Geological Survey. Retrieved 2023-04-08.
- ^ "Geologic Unit: Pearl". National Geologic Database. Geolex — Significant Publications. United States Geological Survey. Retrieved 2023-04-08.
Includes Hollenberg Limestone member ...
- ^ D. R. Snow and David Dean (1925). "Rainbow Bend Field, Cowley County, Kansas". Bulletin of the American Association of Petroleum Geologists. 9, Part 2. Tulsa, Oklahoma: American Association of Petroleum Geologists: 982. Retrieved 2023-04-13.
C.N. Gould: Is it not true that at the type location the Abilene formation is a mud or clay conglomerate? E.C. Parker: This bed in the type section at Abilene, Kansas, at the few exposures where it is unaltered [presuming that the conglomerate is altered dolomite] is a soft gray limestone about 2 feet thick. ...Due to this mode of origin, pieces of the green shale above the Abilene limestone (as it might better be named) have been included in some places in the massive bed of secondary limestone. It can no more be called a conglomerate than the top member of the Herington, which is often similarly altered at the type vicinity.
- ^ "Stratagraphic Sections of Kansas Oil Felds". The Wichita Beacon: 79. Oct 2, 1920. Retrieved 2023-04-08.
- ^ Irving Perrine (Feb 22, 1918). "Geological Conditions in Central Kansas". The Hutchinson News: 7. Retrieved 2023-04-08.
Category:Aquifers in the United States Category:Kansas geologic formation stubs Category:Late Pleistocene