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Anderson County Oil and Gas

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Rocks Exposed

The rocks exposed in Anderson County consist chiefly of alternating beds of shale, limestone, and sandstone. They belong to the middle part of the Pennsylvanian system with the exception of deposits of Quaternary age in the stream valleys and some surface gravels of Tertiary (?) age.

Because the regional dip is toward the northwest, the formations crop out in bands having a general northeast-southwest direction. Successively younger beds appear as the county is crossed in the direction of the dip. Escarpments of the limestones extend up the sides of the valleys, inclosing wedge-shaped outcrops of the underlying shales. Surface gravels and geologically recent deposits of clay and sand locally hide the rocks. These combined features furnish many irregularities to the areal geology.

Quaternary System

Recent Series

Unconsolidated clay, sand, and gravel, laid down during the Recent epoch as slope wash or deposits on the flood plains or beds of the streams, are the only representatives of the Quaternary system in Anderson County.

Tertiary (?) System

Surface gravels, composed chiefly of chert pebbles, form a mantle 0 to 20 feet thick over large areas in southeastern Kansas. Although their position has not been mapped in detail, they appear to lie in irregular, broken bands several miles wide. Those in Anderson County are confined almost entirely to the hilltops and ridges. The poor assortment and wide variation in size of the pebbles are striking features. The pebbles are round, subangular, or flat, and most of the angular and flat fragments have rounded edges. Shallow, smooth depressions help make the pieces of gravel irregular in shape. The color is predominantly brown, but the individual fragments may range from clear white quartz to amber-colored chert. From a position several feet from the face of a pit one may detect traces of bedding in places. The beds—more nearly lenses—are made up of pebbles of nearly the same size intermixed with quartz sand ranging from very fine grains to those a quarter of an inch in diameter. Clay occurs in varying amounts. The correct proportion of this sand and clay makes a satisfactory binder when the gravel is used for roads.

The following size analyses from various pits in the county were furnished by Mr. F. T. Bonebrake, county engineer:

Size analyses of chert gravel from various pits in Anderson County
Size opening
Passed Retained
2 1 1/2 3.3   2.2   5.0
1 1/2 1 11.0 11.2 14.3 10.4 7.7
1 3/4 14.2 12.9 17.3 19.5 8.2
3/4 1/2 22.2 18.7 24.9 25.4 15.6
1/2 1/4 18.8 18.1 18.8 14.9 17.3
1/4   30.5 39.1 22.5 29.5 46.1
Total per cent 100.0 100.0 100.0 99.7 99.9
Silt and clay* 15.0 20.8 8.5 3.6 10.0
* Loss by washing.

Fossil imprints indicate that the gravel was derived from chert of upper Pennsylvanian or lower Permian age. Limestones of these ages that contain an abundance of chert crop out in several counties farther west. In some areas, notably the Flint Hills of Greenwood county, sharp-edged fragments of chert, or "flint," have been left after the weathering of their parent limestones.

The rounded edges of the pebbles in the Anderson County gravels seem to justify the conclusion that they have received water transportation, although further rounding may have resulted from solution after the gravel was brought into place. The poor assortment might be accounted for by considerable vertical slump during a long period of weathering.

The age of the rivers that may have spread this material over the southeastern part of the state is uncertain. Later streams, in carving the surface of the land, have cut across the bands of gravel and left remnants of them only in the higher areas. Much of the Tertiary of western Kansas is made up of gravels or gravelly sands that are apparently river deposits. The chert gravels of Anderson County may have been distributed by rivers of the same age. They are tentatively assigned to the Tertiary.

Pennsylvanian System

The Pennsylvanian system is represented by most of the Douglas formation, all the Lansing formation, and the upper half of the Kansas City formation.

Douglas Formation

The Douglas formation is made up chiefly of shale and sandstone, an uppermost member consisting of three limestone beds separated by shale, and another limestone member, thin and non-persistent, about a third of the way up from the bottom of the formation. Most of the formation, represented by a thickness of about 300 feet, crops out in the county. Only the lowest bed of its important limestone member crosses the county line, so nearly all the rocks at the surface are shales and sandstones. The Douglas occupies a wide band in the western third of the county, the topography of which is flat on the eastern side and made up of sandstone-capped hills on the western side. Comparatively little information is available concerning the formation because most of it is made up of soft, poorly exposed shale and because only about 2 per cent of the wells have been drilled within its outcrop.

Geological divisions of Anderson County, and their relation to other rock formations of Kansas.
Quaternary system  
Recent series  
Alluvium (includes sand, gravel and clay deposits along streams in Anderson County)  
Pleistocene series  
Glacial deposits (northeastern Kansas)  
Tertiary system (western Kansas) (surface gravels in Anderson County?)  
Cretaceous system (western and north-central Kansas)  
Comanchean system (south-central Kansas)  
Permian system (central Kansas)  
Pennsylvanian system (eastern Kansas)  
Missouri group  
Wabaunsee formation  
Eight limestone and shale members  
Shawnee formation  
Nine limestone and shale members  
Douglas formation Exposed in Anderson County
Oread limestone member
Lawrence shale member
Iatan limestone member
Weston shale member
Lansing formation
Stanton limestone member
Vilas shale member
Plattsburg limestone member
Lane shale member
Kansas City formation
Iola limestone member
Chanute shale member
Drum limestone member
Cherryvale shale member
Winterset limestone member
Galesburg shale member  
Bethany Falls limestone member  
Ladore shale member  
Hertha limestone member  
Des Moines group  
Marmaton formation  
La Cygne shale member  
Lenapah limestone member  
Nowata shale member  
Altamont limestone member  
Bandera shale member  
Pawnee limestone member  
Labette shale member  
Fort Scott limestone member  
Cherokee shale  
Mississippian system  
Devonian and Silurian systems? Not exposed in Kansas
Ordovician system
Cambrian system
Pre-Cambrian rocks

Oread limestone member—The lowest of the three limestone beds of the Oread member forms a high escarpment in the vicinity of Amiot. It is a buff thin-bedded crystalline limestone about 5 feet thick that weathers into small rounded blocks. Among the many fossils, Foraminifera of the genus Fusulina are the most abundant.

Lawrence shale member—An abundance of arenaceous material, chiefly sandy shale, characterizes this member. Sandstones in the Lawrence cap the rolling hills in the western part of the county, holding up the scarps as do the limestone caps in the eastern part, but not as effectively. A thin coal seam is reported to occur in this unit in the vicinity of Westphalia. A few thin limestones are recorded in the log of the only well in the county which was started above the Lawrence. This log shows 193 (?) feet of the member.

Iatan limestone member—No positive identification of this limestone has been made by the writer. In other localities outside of Anderson County it is thin, and rarely forms a prominent outcrop. It is probable that the Iatan is thin in Anderson County and for that reason is not well exposed. Near Westphalia are two yellowish-weathering finely crystalline fossiliferous limestones about 2 feet thick, separated by 3 to 10 feet of shale. Perhaps these beds represent the Iatan member of the Douglas formation.

Weston shale member—The Weston crops out along the eastern side of the wide shale area between the Ore ad limestone escarpment and the escarpment of the uppermost limestone of the formation beneath the Douglas. It consists of blue and gray clayey shales containing very little sand. This lack of arenaceous material distinguishes it from the Lawrence shale. The Weston is estimated to be 90 to 100 feet thick.

Lansing Formation

The entire thickness of the Lansing formation, totaling 190 to 260 feet, is exposed and its outcrops occupy a wide band extending northeast-southwest across the central part of the county. About a fourth of the formation, lying near the top, is calcareous. The remainder is made up essentially of shale or sandy shale, a few irregular lentils of sandstone, and local thin limestones.

Stanton limestone member—The Stanton is made inconspicuous by its occurrence a short distance above the thicker and more massive Plattsburg limestone. The member is 2 to 20 feet thick at the surface but attains greater thickness in the southern and western parts of the county, where 35 to 50 feet of it have been logged. The Stanton is thin-bedded, dense, and light gray to white, and weathers into small, thin, smooth, white to yellowish slabs. Locally it is made up of two limestone divisions, an upper white crystalline bed and a lower dense dark gray bed that is given a porphyritic appearance by protruding crystals of calcite. The two beds are separated by 2 to 4 feet of shale. Where the Stanton is thin, only the upper white bed is present.

Vilas shale member—This shale member of the Lansing formation is much thinner in Anderson County than in its type locality in Wilson County. Its most striking feature is the very abrupt and inconsistent manner in which it thickens and thins, but there is no evidence to show that this condition is due to other than uneven deposition. The thinnest occurrence is in the NE sec. 1, T. 21 S., R. 19 E., where 1 foot of shale includes all of the member. The greatest thickness is reported from the Colony gas field, where 40 feet was logged in several wells. In T. 21 S., R. 20 E., and T. 22 S., R. 20 E., it varies between 9 and 27 feet. No single measurement can be applied over more than a small area. The member is greenish or bluish gray. It is sandy in places and contains some thin lenses of brown sandstone.

Plattsburg limestone member—This limestone, with the Stanton, from which it is separated by the thin Vilas shale, forms a steep double escarpment that is continuous for many miles. The escarpment is especially high and prominent along the valleys near Garnett and in the northeastern part of the county. The rolling hills west of Bush City and those in the vicinity of Welda and Colony are capped by these limestones.

The Plattsburg has a variety of lithologic characters which are revealed under the influence of weathering. The sides of its steep escarpments are covered with yellowish-brown fragments scattered several feet below the base of the outcrop. On gentle hillside slopes the limestone occurs as large smooth white to gray partly-buried slabs. On flat surfaces it commonly weathers into irregular pitted blocks 2 or 3 inches to 4 feet square. A considerable resemblance exists between the Plattsburg limestone in these latter exposures and the Iola limestone. However, the weathered fragments of the former are smaller and are more easily hidden by vegetation.

Beds of greenish-gray shale from 1 inch to 3 feet thick separate some of the limestone beds. These breaks are not regular in thickness or lateral extent. A common feature is a basal bed of dense limestone 6 inches to 3 feet thick. This bed weathers into brownish-yellow blocks that are used for building stones. In places it is separated from the main member by 1 to 3 feet of greenish-gray shale. Locally, thin chert beds are interbedded with the limestone. The brown chert fragments are mingled with the limestone fragments in the outcrops.

One of the best vertical exposures is in the quarry two miles north of Garnett and just east of the main road to Ottawa. This unweathered 20-foot exposure is made up of massive beds. A majority of them are fine-grained, but some are coarse-grained and contain gnarly veins of crystalline calcite. The limestone is grayish-white and sparsely fossiliferous at this place. A thin stratum of gray shale between two of the beds has uneven wavy contacts such as might be made by a current or waves.

The thickness of the member where observed by the writer ranges from 10 to 46 feet. It is thinnest in T. 20 S., R. 21 E., and in a general area within a radius of five miles of Greeley. The maximum thickness is in the eastern half of sec. 9, T. 21 S., R. 19 E. According to well records this maximum thickness observed on the surface is exceeded in the southwestern part of the county, where, in wells at Colony, 60 feet of Plattsburg has been reported. However, it happens frequently that a hard, calcareous sandstone a few feet below the top of the Lane shale, which underlies the Plattsburg member, is logged as part of the Plattsburg. For this reason the thickness shown in logs may be above the true figure.

This limestone contains many fossils, most of which are well preserved.

Lane shale member—The Lane consists of gray and greenish-gray shale and sandy shale, lenticular sandstones, and some irregular lenses of limestone. It is 65 to 175 feet thick. The maximum thickness occurs about a mile north of Garnett in the eastern part of T. 20 S., R. 19 E., and the western part of the adjoining township on the east. From this area it thins toward the east, north and west. The following table gives the variation in thickness as shown by well records:

Variation in thickness of the Lane shale in Anderson County, Kansas
Locality Approximate
in feet
Between Garnett and Bush City 160
Between Bush City, Kincaid, and Lone Elm 140
Between Welda and Colony 110
Near Northcott 100
Near Westphalia 100
Near Harris 70
Near Glenloch 130
Near Central City 90
Near Greeley 65

Nine miles east of Garnett, in secs. 33 and 34, T. 20 S., R. 21 E., both the upper and lower contacts of the Lane may be observed. At this point the thickness is 110 feet.

The best partial section of the Lane is in the SE sec. 33, T. 20 S., R. 20 E., in a bluff formed by the east bank of South Pottawatomie creek. The section is a follows:

Partial section of the Lane shale in Anderson County, Kansas (in descending order)
1. Grayish impure fossiliferous limestone which weathers brown. 1
2. Massively bedded fine-grained calcareous sandstone, resistant to weathering. Some shale breaks 4 inches to 1 foot thick, not persistent laterally. Tops of sandstone beds ripple-marked. Reddish-brown blotches on exposed surfaces. 12
3. Very thin-bedded gray sandstone. Splits along bedding planes and exposes an abundance of tiny flakes of mica. Contains plant remains. 4
4. Greenish-gray sandy shale which weathers readily. In places has flow structure. 20
5. Bluish-gray poorly bedded sandy shale. Contains thin beds of calcareous sandstone which form ledges in the softer shale. 29
6. Poorly exposed, very sandy gray shale. 47

The following section was measured four and a half miles north of Garnett in the NE NE sec. 1, T. 20 S., R. 19 E.:

Average section of upper part of Lane shale in Anderson County, Kansas. (in descending order).
  Base of Plattsburg limestone  
1. Greenish-gray sandy shale 17
2. Very calcareous sandstone. Upper part massive and fossiliferous. Some thin shale breaks in lower part. 6
3. Brown sandstone and gray sandy shale. 2
4. Gray sandy shale 2
5. Brown sandstone. 1
6. Gray, thin-bedded shales. 3

The calcareous sandstone in the above section is generally present at approximately the same horizon over most of Anderson County.

An exceptional feature of the Lane is a large lenticular body of limestone which occupies the middle of the member in the southwestern quarter of T. 21 S., R. 19 E., in the southeastern part of T. 21 S., R. 18 E., and the northern two-thirds of T. 22 S., R. 19 E. This stray limestone is thickest in secs. 31, 32, and 33, T. 21 S., R. 19 E., where it is 50 feet. One or two shale breaks occur in it in this locality. It is described in some of the well records as gray and hard.

Kansas City Formation

The part of the Kansas City formation that is represented among the exposed rocks includes the following members: Iola limestone, Chanute shale, Drum limestone, Cherryvale shale, and Winterset limestone. The thickness of the exposed section is 125 feet.

Iola limestone member—The Iola forms the rocky walls of long, narrow, shallow valleys, the slopes of which are covered profusely with irregular limestone fragments. Thin irregular crystalline grayish-white beds predominate, but a few massive beds 1 to 2 feet thick are locally present. Fossils occur sparingly. The Iola maintains a rather uniform thickness of 25 to 35 feet throughout the area of its outcrop in the eastern and southeastern parts of the county. This limestone is better known in Anderson County as a subsurface formation, because the line of its outcrop is east of the section in which most of the wells have been drilled.

Chanute shale member—The Chanute member is a grayish shale which contains local sandy shales and calcareous sandstones. Very thin seams of impure coal and beds of shale containing plant fossils suggest the continental origin of at least part of the member. The thickness of the Chanute is 10 to 60 feet.

Drum limestone member—The chief characteristics of this limestone, its numerous and abrupt changes in thickness and composition, are maintained in this county. In one locality the Drum is a single medium-grained gray fossiliferous limestone bed 8 to 10 inches thick. The exposed surface of the bed is light yellow. It breaks off, where undermined by the weathering of the underlying soft shale, into slabs 1 to 4 feet wide and 2 to 8 feet long. The surfaces of the slabs are made irregular by smooth-faced pits and numerous fossil fragments, including brachiopods, bryozoans, and crinoid stems. It is probable that the Drum is impure sandy limestone in some places. The member varies in thickness from a few inches to 10 feet. If all the strata between and including two thin limestones as shown in some well logs are considered to be the Drum, then it is as much as 35 feet thick at its maximum. However, in such cases it is likely that the upper bed is the Drum limestone and the lower one a calcareous sandstone or sandy limestone member of the Cherryvale shale.

Cherryvale shale member—The Cherryvale is a light, greenish-gray, soft, clayey shale that is rarely exposed. A few iron-stained bands on weathered vertical exposures indicate that the amount of iron oxide varies in the different strata. The member is 20 to 35 feet thick.

Winterset limestone member—This is the oldest formation exposed in Anderson County. It crops out in a few places along the eastern boundary of the county. The Winterset is made up of thin, irregular beds of hard, dense gray limestone. Weathering has tinged some of the exposed fragments a faint yellow. Fossils are plentiful and chert nodules may be found in the uppermost beds. A massive bench of irregularly bedded limestone about 20 feet from the top crops out more prominently than the rest of the member. Large pitted blocks have broken from this bench. The reddish-brown soil immediately above the Winterset is mixed with angular fragments of chert. The thickness ranges from 30 to 40 feet.

Rocks Not Exposed

The unexposed rocks of Anderson County range from those of Pennsylvanian age to the oldest rocks known, the Pre-Cambrian. By correlating the formations from other areas, particularly from Oklahoma, where the older rocks have been given detailed study, it has become known that some of the major divisions of geologic time are not represented among the unexposed rocks of this district. However, those present, besides the Pennsylvanian and Pre-Cambrian rocks, are parts of at least three systems-the Mississippian, Ordovician, and Cambrian.

Pennsylvanian System

The buried Pennsylvanian formations continue without a break beneath those described under "Rocks Exposed." They comprise part of the Kansas City formation, all the Marmaton formation, and the Cherokee shale. The several members of each of these units are listed in the table [previous]. Because these formations are not available for detailed examination, only the major features of each formation, treated as a whole, will be mentioned.

Kansas City Formation

The entire Kansas City formation has a very constant thickness of 200 to 225 feet in Anderson County, of which 60 to 70 per cent are limestones. The uppermost member, the Iola limestone, which, as previously noted, dips beneath the surface in the southeastern part of the county, is the best-known of all the unexposed rocks. Because of its uniform occurrence, constant thickness, and easily distinguishable position in the stratigraphic column, it is always recognized by drillers. Sands or water horizons are frequently identified by their position in reference to the top of the Iola limestone.

The lower part of the formation is made up of three massive limestones separated by black, carbonaceous shales, 5 to 10 feet thick. This lower group has a thickness of 100 to 125 feet and, because of the predominance of limestone, is commonly referred to as the "big lime." It includes the following members: Winterset limestone, Galesburg shale, Bethany Falls limestone, Ladore shale, and Hertha limestone. The two shale members of this series are water-bearing.

Marmaton Formation

The Marmaton is made up of alternating limestones and shales and comprises members from the La Cygne shale to the Fort Scott limestone, inclusive. The thickness varies between 300 and 375 feet. On the basis of lithologic character the Marmaton may be divided into two parts, an upper part consisting of 150 to 175 feet of shale generally free of both sandstone and limestone, and a lower part, 150 to 200 feet thick, containing thin, persistent limestones separated by shales. The large body of shale comprising the upper part of the formation, the "big shale" of drillers and operators, is made up of the La Cygne and Nowata members. The Lenapah limestone, which normally separates them, is absent over most of Anderson County, but it may be represented by a thin limestone recorded in the logs of a few scattered wells. A thin sandstone or sandy shale that is found locally in the Nowata shale is at the same horizon as the Peru-Wayside (Williams, 1921) sand of Montgomery and Chautauqua counties. In places a non-persistent sandstone occurs in the shale (Bandera) beneath the uppermost limestone (Altamont) of the lower part of the Marmaton. This sandstone, referred to as the "600-foot" sand, corresponds in position to the Weiser sand (Williams, 1921) of southeastern Kansas.

Cherokee Shale

The Cherokee shale in Anderson County is composed of 350 to 450 feet of undifferentiated shale in which are included sandstones of irregular character and extent. Dark blue, dark gray, and black shales predominate, but some light blue, light gray, and white strata are present. Pyrite is a common constituent of some of the beds. Their lithologic character varies considerably both laterally and vertically. Sandstones and sandy shales are replaced by pure clay shales within short distances.

Most of the sand bodies occur at two horizons in the upper part of the formation, but many lenses of sand and sandy shale are scattered throughout its extent. The larger sand lenses are 80 to 150 feet below the top. Other sand bodies, which have the characteristics of shallow water and river channel deposits, occur 20 to 40 feet below the top. If the origin of the latter is correctly interpreted, the latter part of Cherokee time must have been marked by the emergence and erosion of the newly formed shales. [Note: This emergence is not believed by the writer to be of sufficient importance to place the top of the Cherokee formation at the channel horizon as has been suggested. Probably the Cherokee sea was rather shallow in eastern Kansas as evidenced by shallow-water sand deposits and deposits of coal. Locally the sea withdrew for short periods, during which natural drainage systems developed. The Anderson County channel deposits are believed to have been formed during one of these periods. Similar channel deposits in Allen and Neosho counties are 200 feet below the top of the Cherokee. This shows that like conditions took place earlier in Cherokee time. In answer to the suggestion that the channel deposits of the two areas were laid down at the same time and represent a single widespread condition, it is pointed out that it is not justifiable to correlate as the same, deposits only 50 'miles apart, separated by such a wide vertical range in a formation having the same thickness at each place.] The thickness of the formation does not vary regularly in any direction. This is probably due to: (1) the shales having been laid down on an unevenly eroded Mississippian floor, (2) the unconformities in the upper part of the formation, (3) the several natural causes of the uneven distribution of muds during deposition.

Mississippian System

The chief component of the Mississippian rocks is 275 to 325 feet of very hard, crystalline limestone, with characteristic white or light gray color, that is referred to by the operators and drillers as the "Mississippi lime." The top of this limestone ranges in depth from about 900 feet in the southeastern part of the county to 1,400 feet in the northwestern part, as effected by the dip and topography. Large amounts of chert occur, especially in the upper part. A very irregular zone of sand or sandy limestone, 0 to 50 feet in thickness, is generally present 5 to 40 feet .below the top of the formation. This zone is widely distributed over eastern Kansas and northeastern Oklahoma and is popularly called the "first break" in the "Mississippi lime." The rocks of Mississippian age in Anderson County are a continuation of those which crop out in the extreme southeastern corner of the state. They are referred to the Boone formation (Moore, 1920).

Mississippian (?) System

A short stratigraphic unit composed chiefly of shale which underlies the thick Mississippian limestone in eastern Kansas is called the "second break" in the "Mississippi lime." The upper part of this unit in Anderson County consists of 30 to 40 feet of blue shale underlain by 10 feet of brownish gray limestone. In view of the fact that a locally occurring deposit below these strata has been classified as of Mississippian age, it appears that the limestone and blue shale are also of that age. [Note: Samples of this limestone and shale furnished the geological department of the Atlantic Oil Producing Company, Tulsa, Okla., were identified as of Kinderhook age.]

Forty feet of black shale makes up the lower part of the "second break" in the southwestern part of the county. A part of this shale may be represented at the same horizon in the remainder of the county, but it has not been identified, due to the lack of samples and proper descriptions in the logs. This black shale has been correlated tentatively with the Chattanooga of Oklahoma and Missouri, which is considered now to be of lower Mississippian age, rather than of Devonian age (White 1926).

Ordovician and Cambrian Systems

A thick series of limestone and dolomitic limestones with a few intercalated beds of shale are the representatives of the Ordovician and Cambrian systems in eastern Kansas. Only a general idea is had of the character or thickness of these strata beneath Anderson County because no well has completely penetrated them. The deepest one of which a record has been obtained was drilled into them 1,125 feet. A well at Iola, 10 miles south of Anderson County, was drilled through 2,200 feet of them without reaching the basement igneous rocks. The top of the Ordovician-Cambrian series is nearly flat and probably is a nearly base-leveled erosional surface that has been made porous by weathering. It invariably holds water in this part of Kansas. However, it is worthy of mention that small oil and gas pools occur in this zone in southeastern Kansas, where many more deep tests have been drilled than in Anderson County. Deep wells in Wilson and Woodson counties have shown that 25 to 125 feet of arkosic sandstones is between the Cambrian limestone and the granitic rocks of Pre-Cambrian age. This sandstone may be expected to continue across Anderson County.

Pre-Cambrian Rocks

The oldest rocks beneath the surface comprise the "basement complex" on which all the later formations have been deposited. These basal rocks probably lie at a depth below 3,000 feet. Where they have been encountered in adjoining counties, they consist mainly of schists and granites. Rocks of the same type, and very likely of about the same age, are exposed in the mountain ranges which border the Midcontinent region. Some of these ranges are the Arbuckle and Wichita mountains of Oklahoma, the Rock Mountains of Colorado and adjoining states, and the Black Hills of South Dakota.

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Kansas Geological Survey, Geology
Placed on web Feb. 6, 2018; originally published June 15, 1927.
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