By George H. Girty
In the paleontologic field, the study of well cores is likely to be attended by the maximum of labor and the minimum of result. Whatever may be said of the microfossils, the story is quite different with regard to shells of ordinary size. Most of the specimens recovered consist of fragments of large shells, with now and then a small shell that is whole and belongs to some small species or is an immature representative of some large one.
In some of the well cores examined and reported upon below, fossils are remarkably abundant in certain zones, but their evidence is qualified by the facts just stated. It has been possible to make many generic identifications upon fragmentary specimens and even some specific identifications if the fragments are large. Even where it has been possible to assemble a respectable faunal list by genera, however, the list may have slight value as evidence for age determination, because most Carboniferous genera have long ranges. Indeed, many species are so closely related to others of a different geologic age that reliable identifications are hardly possible on one or two specimens, for the variation in each is such that one species, so to speak, overlaps with some other species. Indeed, in my experience, there are few guide fossils in our Carboniferous faunas, and it is necessary to rely upon faunal associations for age determination and not upon single species. It is rarely possible to recover enough determinable fossils from well cores to constitute an adequate faunal association.
In these well cores the faunas consist of bryozoa and brachiopods but hardly any other zoologic types. Among the bryozoa fronds of Fenestrellina and Polypora are at some horizons very abundant. I have not attempted to identify them specifically, because to do so would be laborious and the results of uncertain value. Some of the other bryozoan types could not be identified without thin sections, and for similar reason these too have not been specifically identified. As mere genera, on the other hand, most of these types have no stratigraphic significance. There are two bryozoa, however, that are more or less abundant in the well cores, that can be identified generically with reasonable assurance, and that have value as evidence in age determination. The genus Hemitrypa has a known range from Keokuk to St. Louis. It has been recognized in several samples and probably occurs in many others, for it can be recognized only when one side of the frond is exposed. If the other side is exposed it is indistinguishable from Fenestrellina. Worthenopora spinosa also occurs abundantly in many samples and has a range from Keokuk to Spergen. Archimedes was recognized in a fragment in one collection and it ranges from Keokuk upward.
Among the brachiopods the genus Spirifer is preeminently abundant, but most of the specimens belong to a type that is represented at many horizons and goes by different names. The species are probably valid, but then cannot be identified satisfactorily on a few specimens or on fragmentary ones. I mean the line of descent represented by S. keokuk, S. bifurcatus, S. pellensis, and S. increbescens, not to mention other species related to them. Not all the Spirifers in these cores, however, are of this type. There is a finely ribbed form that seems to be S. tenuicosta (Keokuk to Spergen), another that seems to be S. lateralis (Warsaw and Spergen), a third that seems to be S. subaequalis (Warsaw and Spergen) , and a fourth that seems to be S. bifurcatus (St. Louis and, according to Butts, basal Warsaw). There are other forms that have stratigraphic significance but occur more rarely in the samples. They are commented upon in connection with the samples in which they were found.
In weighing the significance of the species recognized in the well cores I have had to depend chiefly upon their recorded ranges, without a critical examination or verification of the records as of the present day. Some of the identifications recorded may be incorrect and the supposed range too great. On the other hand, as facts accumulate, some of the ranges may be increased.
Taken as a whole, the well cores record faunas of Warsaw, Spergen, St. Louis, and possibly Ste. Genevieve ages, but it rarely happens that two of them can be definitely recognized in anyone core. They are probably represented, but Mr. Lee will have to determine their positions by comparisons of depth with relation to the height of the well head above sea level. Furthermore, I have been unable to indicate the boundaries of any formation or period, and consequently, the thickness of rock that represents it. Most of the conclusive evidence occurs in a sample or samples taken from but a few feet, with only nondescript faunas above and below. None of the diagnostic forms indicates all age older than Keokuk but many of them appear first in the Keokuk and range upward from there. The Burlington would seemingly be unrepresented in the cores and it is doubtful if the Keokuk is represented in them. Some of the forms that have definite stratigraphic significance begin in the Keokuk, but I have seen nothing that is distinctive of that period. As most of the Keokuk faunas of the Boone occur in or are associated with cherty beds, as the well cores consist chiefly of limestone or at most contain little chert, and as Lee tells me that cherty beds are numerous below the core samples sent me for examination, it seems probable that the lowest samples considered in my report are Warsaw, although by reason of the ambiguous faunal evidence they might be either Keokuk or Warsaw.
I should also mention that in searching for paleontological evidence in the cores I have relied greatly upon Mr. W. R. Hass, who broke up and selected the fossiliferous specimens. I began by looking over all the fragments in a sample myself and continued to look over a piece or two in many lots, but I found that Mr. Hass had made a very accurate selection. I concluded that in general any fossil that was so obscure that he overlooked it would also be too poorly preserved to add much to the paleontological evidence.
Well of the Carter Oil Company
Core numbers indicate depth below the surface.
No. 1 Everett, sec. 22, T. 29 S., R. 21 W., Ford County (well No. 6, cross section F-F', pl. 7)
Core 5428-5432. Many fragments, but few that can be recognized or are significant. A Spirifer, probably S. tenuicosta (Keokuk, Warsaw, and Spergen), a large Reticularia, type of R. pseudolineata, fragments of a large Productus and a small undeterminable Pustula?. Geologic age not older than Keokuk and possibly as young as Spergen. It cannot well be Spergen as it occurs below probable Warsaw and is, tentatively, itself Warsaw.
Core 5425-5428. Fauna much like the foregoing, but not so good.
The only additional form with significance is Worthenopora spinosa (Keokuk, Warsaw, and Spergen).
Core 5422-5425. Fossils numerous, but limited in variety. Spirifer lateralis, Spirifer of the keokuk-washingtonensis-pellensis group and Cliothyridina? sp. If Spirifer lateralis is correctly identified, the zone is probably Warsaw. The species is recorded as Warsaw and Salem but is commonly regarded as a distinctive Warsaw form.
Core 5419-5422. Spirifer subaequalis (Warsaw and Spergen), S. lateralis, Spirifer aff. S. washingtonensis, and a few other forms by fragments. Warsaw is indicated.
Core 5419-5404 (samples 5417-5419, 5416-5419, 5413-5416, 5410- 5413, 5407-5410, 5404-5407). Little except fragments and nothing of significance.
Core 5401-5404. A rather varied fauna, though many of the forms have no stratigraphic significance. The most notable are Spirifer aff. S. pellensis (abundant), Spirifer tenuicosta, Pustula ozora?, Echinoconchus biseriatus, Worthenopora spinosa; Warsaw age indicated.
Core 5398-5401. Fossils abundant; fauna much like the foregoing, but not so varied. Worthenopora spinosa, Pustula ozora, Spirifer lateralis, Spirifer aff. S. bifurcatus (abundant); Warsaw age indicated.
Core 5395-5398. Fossils abundant, fauna much like the foregoing. Worthenopora spinosa, Spirifer aff. S. bifurcatus (a Spergen species, but I have it in the Joplin Warsaw), Echinoconchus biseriatus. Other forms fragmentary and without significance. Warsaw again indicated.
Core 5392-5395. Very fossiliferous. Fossils mainly bryozoa. Fauna like the preceding. Worthenopora spinosa, Echinoconchus biseriatus, Pustula ozora, Avonia williamsiana?, Spirifer tenuicosta, Girtyella turgida? (a Spergen species), together with several other forms, either fragmentary or lacking in interest. Geologic age seemingly Warsaw.
Core 5375-5392 (four samples, designated first 2 feet recovered, last 2 feet recovered, third 2 feet recovered, and second 2 feet recovered). Fossils not abundant. The fauna is small, but like the foregoing. Worthenopora spinosa, Echinoconchus biseriatus, Spirifer aff. S. bifurcatus, Spirifer tenuicosta?, and a few other forms, none of them worth recording. There is no reason to differentiate this fauna from the preceding.
Core 5361-5375 (two samples, designated first 2 feet recovered, and last 2 feet recovered). Fossils scanty and fauna small. Identifications mostly indefinite. Note should be made of Worthenopora spinosa and a large spiriferoid having a punctate shell and seemingly belonging to the genus Spiriferella, as Weller used that name. The only species referred to Spiriferella in this country occur in the Burlington and Keokuk, but I have seemingly the same species in the Warsaw fauna of the Joplin area. The same form occurs in the well of the Atlantic Oil Production Company at a depth of 5,088 to 5,097 feet. There seems to be no reason to differentiate this bed from the preceding.
Core 5360-5341 (two samples, designated first 2 feet of 5 feet recovered, and last 2 feet of 5 feet recovered). Fauna much restricted. Fenestrellina, Polypora, Worthenopora spinosa, and a few fragments.
Core 5341-5306 (12 samples, 5339-5341, 5336-5339, 5333-5336, 5330-5333, 5327-5330, 5324-5327, 5321-5324, 5317-5321, 5314-5317, 5311-5314, 5308-5311, and 5306-5308). Fossils generally scanty and fragmentary. The faunas are sparse and many of them without distinctive characters. Worthenopora spinosa, which occurs chiefly in the Keokuk and Warsaw, but is known also in the Spergen, was recognized in several of these samples, including the last (5306-5308). Sample 5330-5333 contains a better fauna than the rest, but the only significant things are Worthenopora spinosa, Hemitrypa sp., and another bryozoan, which seems to belong to the genus Diplopora, a genus that at present is not known below the Chester. There is also a small Spirifer related to pellensis, and a small Productus. The association of Worthenopora spinosa and Hemitrypa sp. is found also in sample 5308-5311, which contains in addition a species of Sulcoretepora, a genus that, though not mentioned before, has been recognized in numerous samples.
The next sample, 5278-5283, contains Fenestrellina (fragments), a rhynchonellid, which I would not undertake to identify, and Cliothyridina? sp.
In summary: The lowest fossiliferous bed, 5428-5432, can hardly be older than Keokuk, but may be younger. As a Warsaw fauna makes its appearance slightly higher, this lot would probably be best so referred. Warsaw faunas seemingly continue up to and include sample 5306-5308, a thickness of about 125 feet. So far as the evidence goes, the Warsaw very likely ranges up to include samples 5278-5283. At least there is nothing out of keeping with Warsaw and nothing definitely suggestive of Spergen.
The significant forms in the part of the core here referred to the Warsaw (5422-5425 to 5306-5328) are as follows:
|Worthenopora spinosa||Keokuk, Warsaw, Spergen|
|Echinoconchus biseriatus||Keokuk?, Warsaw, Spergen|
|Avonia williamsiana||Keokuk, Warsaw|
|Spirifer lateralis||Warsaw, Spergen|
|Spirifer subaequalis||Warsaw, Spergen|
|Spirifer tenuicostus||Keokuk, Warsaw, Spergen|
|Spirifer bifurcatus||basal Warsaw, Spergen|
It will be observed that the recorded ranges of these forms overlap, some going down into the Keokuk, some going up into the Spergen, but the only zone in which all occur together is Warsaw, There is no definite evidence of Keokuk nor any definite evidence of Spergen. Furthermore, the parts of the core above and below the section here regarded as Warsaw, which are poorly characterized faunally, are nevertheless tied faunally to the Warsaw part and I find no reason in paleontology for believing the one to be Keokuk or the other Spergen. Such possibilities, however, are not to be dismissed.
Well of the Atlantic Oil Production Company
No. 1-A Mark, sec. 28, T. 20 S., R. 33 W., Scott County, (well No. 3a, cross section. F-F', pl. 7)
Beginning at the bottom of the section there are four samples from about the same zone. One has a given depth of 5088 to 5091 feet, the three others are alike, 5088-5097. This zone is abundantly fossiliferous, but most of the fossils are fragmentary and otherwise poorly preserved. Bryozoa are numerous, but it would not be profitable to identify them specifically. The following are significant: Hemitrypa (Keokuk to St. Louis), Archimedes (Keokuk and later), Worthenopora spinosa (Keokuk, Warsaw, and Spergen). Few of the brachiopods are identifiable specifically and the generic identifications mean little. Especially notable is a large punctate Spirifer seemingly belonging in the genus Spiriferella, as interpreted by Weller. The same striking species occurs in the Carter-Everett well in a fauna that I interpret as Warsaw. The same or a closely related species is found in the Joplin Warsaw. Mention may also be made of Spirifer tenuicostus (Keokuk, Warsaw, Spergen), a species of Reticularia (abundant) and a rhynchonellid (abundant). I believe that these samples represent the Warsaw zone of the Carter-Everett well, but the rock here is darker and very cherty.
Sample 5065-5068 contains no fossils.
Five samples (5060-5065, 5060-5065, 5055-5060, 5050-5065, 5050- 5055) contain fossils, but nothing distinctive. General suggestion of Keokuk or Warsaw. Sample 5060-5065 marked "Cowley chert".
Three samples (all marked 5035-5050) contain little that is instructive. One marked "third foot" contains a specimen of Avonia williamsiana, a species that I recognize in the Keokuk and Warsaw faunas of the Joplin region.
Four samples (5033-5035, 5030-5035, 5026-5030, and 5019-5026) are also more or less-noncommittal, but not differentiated faunally from the Warsaw below. One of them contains Worthenopora spinosa (Keokuk to Spergen) and another (5019-5026) contains one of those elliptical crinoid stems with dentate projections that have sometimes been identified as Platycrinites penicillus (Ste. Genevieve). It is doubtful if this fossil is reliable as a zone marker or that it has such significance here.
The four samples (5012-5019, top of 5012, 5000-5012, 4993-5000) present problems. Sample 5012-5019 contains no fossils. Sample top of 5012 contains a Productus like P. cora or P. ovatus, but more like the latter (Mississippian). Several crushed specimens that might represent a Productus of the nebraskeneis group (Pennsylvanian) or a species related to Buxtonia arkansana (a Moorefield and Chester type) and, lastly, a small spiriferoid shell, which seems to be Squamularia perplexa (Pennsylvanian), but is conceivably a very young Reticularia (Mississippian). Sample 5000-5012 contains nothing significant, and sample 4993-5000 contains a Pennsylvanian fauna with Chonetes (Mesolobus) mesolobus and Squamularia perplexa. The age of this fauna is certainly Pennsylvanian, for the range of C. mesolobus is well known and it has always been found in Pennsylvanian rocks. I do not see how a Pennsylvanian bed could occur at this horizon, and if the lot is misplaced I would be, inclined to regard lot 5012 top as also misplaced and also Pennsylvanian.
Four samples ranging from 5000 to 4989 contain nothing significant.
Three samples (4980.5 to 4987.5, 4979-4980 1/2, 4981-4983) represent a somewhat fossiliferous zone, but one whose fauna is not easy to interpret. Bryozoa are numerous, among them Worthenopora spinosa (Keokuk, Warsaw, and Spergen). The brachiopods do not help much, for they cannot be definitely identified specifically, and generically they have long ranges. Spirifers predominate and belong to a type that ranges almost throughout the Mississippian, but goes under different names at different horizons. The evidence of such forms cannot be interpreted safely if the material is poor and small in quantity. Little also can be made of the other brachiopod genera such as Cliothyridina or even of Reticularia. I see no reason to regard this zone as younger than Warsaw and it cannot be older if some of the underlying beds are Warsaw, as they probably are.
Thirteen samples, ranging from 4895 to 4978, with no fossils at all, or with fragments of Fenestrellina. As an exception,. sample 4962-4963 contains a somewhat doubtful fragment of Worthenopora spinosa.
Three samples (4891-4895, 4889-4891, and 4885-4887) represent another fossiliferous zone. The two samples (4891-4895 and 4889- 4891) are much alike faunally, though the faunas are small. I recognized only three species, a rhynchonollid (probably Camarotoechia) , which is without significance, another rhynchonellid, which closely resembles Moorefieldelia eurekensis (almost diagnostic of the Moorefield fauna), and a Spirifer, which closely resembles S. bifurcatus (described from the Spergen limestone. but recorded also from the basal Warsaw and related to other species of the same genus.) No species of this type is known in the Moorefield fauna. The sample 4885-4887 contains a different fauna. Productus ovatus is very abundant and a small Spirifer, similar to Weller's Brachythyris altonensis, described from the St. Louis limestone. There are also a few other forms, long ranging or doubtfully identifiable.
Eight samples (4880-4823) that show little or nothing. I may note the occurrence of the same Brachythyris altonensis? in sample 4855- 4861, and seemingly a conglomerate bed at 4861-4863.
Sample 4812-4814 contains a coral commonly identified as Lithostrotion proliferum, which is generally regarded as diagnostic of the St. Louis limestone. This remarkable sample contains parts of numerous corallites, and Mr. Ralph A. Brant of the Atlantic Refining Company of Tulsa has provided me with a photograph showing a cross section of one of them.
The rest of the samples, 16 in number, contain nothing that is diagnostic, or else nothing at all. In thickness this part of the section extends from a depth of 4,810 feet to a depth of 4,087 feet. Noticeable, but not significant, is a sample from 4789-4790, which cuts through a colony of Syringopora. It also contains a terebratulaid, which may well be a small specimen of Girtyella indianensis. That species was described from the Ste. Genevieve limestone and if the identification is correct it carries a suggestion that the sample is of that age. Mention may also be made of a poorly preserved Euomphalus in light-colored limestone at a depth of 4,192 to 4,194 feet.
In summary: The lowest zone contains a fauna that with reasonable probability is Warsaw in age. Some distance above this zone (4812-4814) occurs a fauna that on generally accepted evidence would be St. Louis. There is some evidence that some of the beds below 4,814 feet are also St. Louis. It is a fair assumption that beds of Spergen age are present in the core between the Warsaw and the St. Louis, hut there is no specific evidence of the fact. The presence of samples of Pennsylvanian age referred to this part of the core is a disturbing factor in the evidence, even granting that the reference was due to carelessness. There is some evidence also that beds of Ste. Genevieve age are present above the St. Louis, but there is nothing in the paleontologic evidence to establish boundaries between the Warsaw and the Spergen, between the Spergen and the St. Louis, or between the St. Louis and Ste. Genevieve.
Well of the Atlantic Oil Production Company
No. 1-B Mark, sec. 14, T 20 S., R. 33 W., Scott County)
Only two samples were received from this well. One of them marked at depth 4633-4649 is an oil-soaked oolite. The sample of oolite was very small and the fauna obtained from it was also small. The forms recovered are fragmentary or come under the head of microfossils. A complete list is as follows: Triplophyllum? sp., Fenestrellina sp., Rhombopora sp., Sulcoretepora lineata, Aclisina? sp., small indeterminable gastropods. In addition to the foregoing this collection yielded the following ostracodes identified by P. V. Roundy: Paraparchites carbonarius? , Bairdia permagna, Amphissites sp.
The general facies of this fauna recalls that of the Spergen limestone, although the Ste. Genevieve in places contains a fauna reminiscent of the Spergen. Mr. Roundy, as I recall, was inclined to interpret the ostracodes as indicating Spergen, but I think that the faunal evidence is indecisive. If the horizon of this fauna is above the St. Louis as determined by "Lithostrotion proliferum" in Atlantic No. 1-A Mark, the age is necessarily Ste. Genevieve or at least not Spergen. A conclusion on this head would rest with the stratigraphic evidence.
Wallace Lee has made an annotation on a preliminary draft submitted to him that the field geologists thought they had Ste. Genevieve in an oolitic oil zone at the top of the Mississippian in Mark 1-B, 3 miles north of Mark 1-A. The identification was based on a fossil tentatively referred to Platycrinites huntsvillae. The correct name is Platycrinites penicillus, which I mentioned as possibly occurring in samples 5019-5026 of Atlantic No. 1-A Mark. I do not doubt that the evidence in both instances consists of those elliptical stems surrounded by a serrated flange. Both horizons cannot be Ste. Genevieve in age if a St. Louis zone comes between them and there is some support (Girtyella indianensis) for the Ste. Genevieve age of the upper zone in Mark 1-B if above the Lithostrotion bed of Mark 1-A, though my well core did not contain P. penicillus.
The second sample (depth 4590-4606) contained no fossils. It was a very fine sandstone, olive or brown in color with black patches.
Well of Alma Oil Company and Robert B. McNeeley
No. 1 Watchorn, sec. 13, T. 15 S., R. 33 W., Logan county (well No. 2, cross section F-F', pl. 7)
Core 4631 1/2-4632. Fenestrellina, Orthotetes, Paraparchites and indeterminata. Age not indicated.
Well of Watchorn Oil and Gas Company
No. 2 Morrison, sec. 20, T. 32 S., R. 21 W., Clark county (well No. 7a, cross section F-F', pl. 7)
The five samples 6480-6464 (6473-6480 bottom of core, 6473-6480 middle of core, 6473-6480 top of core, 6464-6470 bottom of core, 6464-6470 middle of core, 6464-6470 top of core) contain nothing that is significant and very little at all. A few crinoid stems, fragments of Fenestrellina, and a Sulcoretepora.
The sample 6462-6464 contains Fusulina and is of Pennsylvanian age. In the conversation between Mr. Lee and me concerning this sample, Mr. Lee said that it was almost certainly misplaced. I would think the same, as there are no other Pennsylvanian samples in the entire core.
The next 13 samples, ranging from 6293 to 6114 (6291-6293 with intermediate samples to 6114-6119), contain no fossils so far as ascertained.
Core 6051-6065 (samples 1-5) contain fossils in sample 1, which is the top, and in samples 2 and 5, as follows: Worthenopora spinosa, fragments of a Spirifer related to S. keokuk and S. washingtonensis, a finely costate Spirifer (fragment) possibly S. lateralis, and Rhipidomella aff. R. dubia. The fossils in these samples are fragmentary and poorly preserved. From the very small fauna the geologic age might be as old as Keokuk, but it is more probably Warsaw, and later ages are not precluded.
Core 6004-6051 (samples 1-4) contains nothing worth mentioning except sample 4 (the bottom one), which agrees with the foregoing.
Core 5976-6004 (samples 1-7) all except sample 1 (top) are fossiliferous. Fossils are fairly abundant in 4, 5, and 6. Worthenopora spinosa (Keokuk, Warsaw, Spergen) is somewhat abundant as are pieces of fenestrellinid fronds. Among the brachiopods, fragments of Spirifer, of the keokuk-washingtonensis-pellensis group. Fragments of other brachiopods (Productus, Dielasma?, Reticularia, and Eumetria verneuiliana?) . Nothing significant except the Worthenopora, and nothing can safely be said about the geologic age except that the fauna is not older than Keokuk and not younger than Spergen.
Core 5947-5976 (samples 1-4). Fossils few and fragmentary. Worthenopora spinosa (Keokuk to Spergen) occurs in all except sample 4. In addition fragments of Fenestrellina and fragments of brachiopods, which cannot be safely identified generically, and even generically would have little weight as evidence. A small rhynchonellid is abundant in sample 3.
Core 5932-5947 (samples 1-4). Very much like core 5976-6004, but not so good. Worthenopora spinosa is found in sample 2. Eumetria verneuiliana in sample 3, which makes the best showing. Fragments of Spirifer and other brachiopods in other lots. The geologic age might be Keokuk, Warsaw, or Spergen; there is no definite evidence for one rather than another.
Core 5917-5932 (samples 1-3). The fauna is essentially the same as in the foregoing. Worthenopora spinosa occurs in samples 1 and 2.
Core 5885-5917 (samples 1-5). No fossils in any but sample 5, which contains Composita aff. C. trinuclea and a few fragments. No evidence that can be estimated.
Core 5871-5885 (samples 1-4). Fossils scanty and fragmentary, no evidence except Hemitrypa (Keokuk to St. Louis), in sample 1, and Worthenopora spinosa in sample 2.
Core 5850-5871 (samples 1-4). Scantily fossiliferous. Fragments of Fenestrellina, Spirifer, and a few other forms. No evidence except what would comport with Keokuk or later.
Core 5833-5850 (samples 1-5). Fossils few and fragmentary, some identifiable generically, some not even that. Nothing distinctive, though Camarotoechia mutata? in sample 1, if it is that species, suggests a Spergen age.
Core 5813-5833 (5 samples). All fossils poor and fragmentary. Some forms not determinable between 2 or more genera. Other forms that can be determined generically cannot be determined specifically. No evidence except that the age seems to be Keokuk or younger.
Core 5793-5802 (5 samples). Fossils scanty and poor. Spirifer (not determinable). Eumetria verneuiliana (long range).
Core 5788-5793 (4 samples). Two samples lack fossils, the others contain but few and those fragmentary and mostly indeterminable. No appreciable evidence.
Core 5758-5776. We come here to a fauna that is quite different from anything yet seen. The rock is a whitish oolite and obviously very fossiliferous, though the material recovered comprises mostly small or fragmentary specimens. The fauna and lithology somewhat pointedly suggest Spergen though very few of the specimens can be definitely identified. The following will show the general character of the fauna present: Fragments of a small, finely plicated rhynchonellid like Camarotoechia mutata, fragments of a small Spirifer, which might be S. bifurcatus, Composita sp., Athyris densa?, Eumetria verneuiliana (fragments), Nucula sp. (fragment), Sphenotus sp. (fragment) and Myalina sp.
Core 5745-5758 (3 samples). Only one sample (at 5748 ±) contains any fossils and these are very few and lack significance.
Core 5736-5745 (4 samples). Three of these are wholly negligible. The one at 5745 contains a variety of forms. Besides the ever-present Fenestrellina and Polypora I find fragments of Productus representing one or possibly two species; fragments of two species of Spirifer, one finely and the other coarsely plicate (S. tenuicostus? and S. bifurcatus?); a Reticularia (fragment); a Cliothyridina (C. hirsuta?); and Girtyella. In addition to these more or less definite fossils, there are two objects that I interpret as sections across a species of Pentremites. None of these forms can be satisfactorily identified, but the general make-up of the fauna suggests an age at least as young as Spergen. As this fauna occurs only about 30 feet above the other fauna that seemed to have Spergen affinities, it seems safe to assign both to that age, the evidence of one reinforcing that of the other. As a precaution, however, it will be well to remember that the faunas contain some types that are alien to the typical Spergen fauna (e. g. Myalina sp. and Sphenotus sp.).
In summary: Except for one outstanding zone, there is little in any of the samples from this well core that is distinctive paleontologically. The outstanding zone, of course, is the one represented by core 5758-5776. If this is Spergen some of the beds above and below are probably also of that age. The higher sample (core 5736- 5745) has already been mentioned. Some of the lower samples, though indefinite, are suggestive of the Spergen fauna showing sporadically a small rhynchonellid resembling Camarotoechia mutata or a Spirifer probably belonging to S. bifurcatus (Spergen and basal Warsaw) as in core 5813-5833. It may be fairly inferred that some of the samples from lower zones are older than Spergen and, unless the Warsaw is absent, that they are of Warsaw age. The fauna of core 6051-6055 is especially suggestive of Warsaw. The evidence furnished by the samples below this level would permit them to be either Warsaw or Keokuk and whether any are of Keokuk age is a question that cannot be decided by the paleontologic evidence present. The evidence is noncommittal except that if some of the lower faunas are of Warsaw age, even the lowest are not differentiated from them in any way, though this may be due to the fact that the evidence obtained from the lowest samples is so scanty and indecisive.
Well of Kessler and Thier, Inc.
No. 1 Wolfje, sec. 17, T. 33 S., R. 6 W., Harper County
Core 4425-4437. [Note: These cores are lithologically and stratigraphically from the Cowley formation. Wallace Lee.] (First foot of recovery) sponge spicules; (second foot) crinoid stems; (third foot) crinoid stems, abundant, fragments of unidentified bryozoa, fragments of shells (Rhynchopora? and Platyceras?); (fourth foot) crinoid stems and fragment of a brachiopod; (fifth foot) abundant crinoid stems; (sixth foot) nothing recognizable; (seventh foot) sponge spicules?; (eighth foot) several fragments of brachiopods (Dielasma?) and a small crushed brachiopod, not determinable; (ninth foot) fragment of a punctate brachiopod and a small crushed brachiopod of uncertain affinities; (tenth foot) nothing recognizable; (eleventh foot) nothing determinable.
Core 4465-4468. (Upper foot of recovery) abundant crinoid sterns and fragments of some brachiopod shell; (second foot) numerous crinoid stems, numerous fragments of Fenestrellina, Polypora sp., Rhombopora? sp., Streblotrypa? sp.; (third foot) numerous crinoid stems, small fragment of Fenestrellina, and Chonetes aff. C. illinoisensis.
These samples offer no evidence whatever as to geologic age. The dearth of any fossils at ail, compared with their abundance in the other well cores is, however, striking and probably significant.
Wells of Magnolia Petroleum Company
Robbins lease, T. 28 S., R. 1 E., Sedgwick County
Robbins No. 4
Core 3082-3086. Worthenopora spinosa and other bryozoa, none of which have been determined, Productus ovatus, Echinoconchus biseriatus (abundant), and Productus indet.
Core 3079-3082. Worthenopora spinosa, Fenestrellina, and undetermined bryozoa, an undetermined rhynchonellid, and fragments of Productus and Spirifer. Geologic age probably Warsaw, nothing very definite and nothing distinctly Keokuk. It might, on the other hand, be post-Warsaw.
Robbins No. 5
Core 3095-3102. Fragments of Fenestrellina and Rhombopora. No suggestions as to geologic age.
Robbins No. 6
Depth not given. Fossils abundant. Worthenopora spinosa and other bryozoa (Sulcoretepora, Rhombopora, etc.), Productus ovatus, Productus setiger, Echinoconchus biseriatus (abundant), fragments of other brachiopods (Productus, Spirifer, Reticularia, etc.). Apparently same zone as Robbins No. 4 (depth, 3082-3086).
Robbins No. 7
Core 3080-3087. Depth,3087 (pieces 1, 2, and 3). Fragments of brachiopods; (piece 4) Productus setiger?; (piece 5) Worthenopora spinosa, Sulcoretepora sp., Fenestrellina sp., Productus setiger?, Echinoconchus biseriatus, Reticularia sp.; (piece 6) Worthenopora spinosa, Orthotetes? sp., Productus setiger, Pustula ozora?, Productus sp., Reticularia sp,
Core 3087-3092 (probably 3087 to 3088). Fossils abundant. Many fragments of bryozoa including Worthenopora spinosa, unidentified species of Fenestrellina, Rhombopora, Sulcoretepora, and other genera. Among the brachiopods are Productus setiger?, Echinoconchus biseriatus, fragments of other Producti, Pustula sp., and Brachythyris altonensis?.
These faunas seem to be mutually related, and although they come from different wells, I judge that the cores do not represent any considerable thickness of rock. Fossils are abundant, but the fauna is small and singularly lacking in forms that would determine its geologic age. An age determination is also handicapped by lack of information about the faunas that come in below and above this one. On the whole I am inclined to regard this fauna as post-Warsaw. One item worth considering is the small Spirifer resembling Brachythyris altonensis, a species that Weller described from the St. Louis limestone. The same species seemingly occurs in the Atlantic No. 1-A Mark in beds not far below a fauna that seems definitely referable to the St. Louis. On this very slender evidence the present fauna might be Spergen if not St. Louis and at least there is nothing in the paleontologic evidence that would refute such an interpretation of its age. The cores from wells No. 4 to No. 7 are from white noncherty limestone directly above porous oil-bearing dolomite believed to be of Cowley age. According to this evidence the Cowley therefore might be Warsaw or even Spergen.
Well of J. E. Trigg et al. (Bates)
No. 1 Nimock, sec. 16, T. 16 S., R. 28 W., Lane county (well No. 24, cross section F -F', pl. 7)
Core 4517 -4527. Bryozoan fragments.
Core 4516. Sulcoretepora sp., Hemitrypa sp., Pustula aff. P. indianensis; geologic age, Keokuk or younger.
Core 4515. Endothyra and other foraminifera, also Fenestrellina; age uncertain, suggestive of Spergen.
Core 4513. No fossils.
Core 4512. Polypora, Platycrinites (stem), Pustula n. sp.; evidence as to geologic age indeterminate.
Core 4505. Fragments of Spirifer.
Core 4504. Fenestrellina, obscure.
Core 4500. Fenestrellina, Dichotrypa?, Pustula sp., Spirifer tenuicostus?, Spirifer sp. (fragment), Brachythyris subcardiiformis, Cliothyridina sp.; probable age, Spergen.
Core 4499. Nothing determinable.
Core 4498. Fenestrellina, Worthenopora spinosa?, Spirifer (fragments). If the age of this lot is Spergen, Worthenopora spinosa is not out of place, although it is rare except in the Keokuk and Warsaw.
Core 4496. Worthenopora spinosa.
Core 4495. Fenestrellina and Sulcoretepora.
Core 4493. Fenestrellina and Echinoconchus biseriatus?
Core 4491. Crinoidal limestone.
Core 4489. Fenestrellina, Sulcoretepora, Productus ovatus, P. ovatus var. minor?, Spirifer sp., Reticularia? sp.; geologic age probably Spergen, at least there is no evidence of St. Louis.
Core 4488. Productus (fragments), rhynchonellid (indet.), Spirifer sp., Reticularia sp., Cliothyridina? sp. None of these forms is specifically determinable, and in combination they afford no evidence as to geologic age.
In summary: Beginning with 4416, we have only 28 feet included in this core, the median part of which seems with some probability to be Spergen in age, and at least there is no reason to believe that the entire 28 feet is not of the same age, whatever that age may be. There is nothing to indicate that the lowest bed is older (Warsaw) or that the highest beds are younger (St. Louis), although these possibilities are not excluded.
Kansas Geological Survey, Geology
Placed on web Jan. 27, 2013; originally published Sept. 1, 1940.
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