L. R. Wilson

Elater-Bearing Spores from the Pennsylvanian Strata of Iowa

In the course of paleobotanical studies of coal balls from the Des Moines Series in the Pennsylvanian strata of Iowa, numerous elater-bearing spores were discovered. A review of the literature on spores of this type showed that none are recorded from rocks earlier than the Triassic. The discovery is therefore significant in that it extends the record from the early Mesozoic Era back into the latter part of the Paleozoic Era. In addition, several interesting structural features are also shown by these Paleozoic spores.

Composite micropaleontology and its application to Tertiary and near-Recent stratigraphy

whereas an investigation of the total fossil microbiota is more effective. Tertiary sedimentary rocks lend themselves well to paleoecological studies, since many of the faunal and floral elements have modern equivalents, and they occur in assemblages similar to those of living forms. For a fuller understanding of Tertiary sediments, it is important that the ecology of Recent aquatic and terrestrial environments be appreciated. Composite studies have aided in more complete understanding of certain paleoecological problems, in closer stratigraphic correlations, and in the discerning of facies trends.

Palynology as a Tool for Economic Geology

The economic value of palynology is an accepted fact but its practice is misunderstood by some oil companies. As in other disciplines, palynology has its limitations. These stem from the unsuitability of the method in certain rocks, a lack of knowledge on the part of the palynologists often hired by managements, the inferior equipment in use, and the absence of literature available. Those companies who understand these problems are successfully resolving many pertinent questions. Suggestions are made that will advance the value of palynology to science and industry.

The Nipissing flora of the Apostle Islands region

In Science, February 13, 1931, a fossil flora of the Nipissing Great Lakes was briefly described by the writer. As was there stated, the plant remains are preserved in the form of rather extensive peat beds submerged in Lake Superior in the vicinity of the Apostle Islands, Bayfield County, Wisconsin. The samples, sent by Prof. J. A. Merrill, of the Superior State Teachers College, were recovered from beneath fourteen feet of sand and forty feet of water about one and one-half miles west of Sand Island, Bayfield County, Wisconsin. The geological significance of this deposit has been discussed by Dr. F. B. Taylor (Science 74: 265-267, 1931.) and the formation of the peat set as contemporaneous with the original one-outlet stage of the Nipissing Great Lakes. The botanical importance of this deposit becomes evident when one reviews literature dealing with the plant life associated with the Glacial Great Lakes. Two facts stand out, particularly: that the actual knowledge of the plants occurring at this period in the history of the Great Lakes is confined to one or more species of Chara (Coleman, A. P., Toronto University Studies, Biol. Sur. No. 21; 1922), and that much hypothetical dating of the appearance of certain Atlantic Coastal Plain plants and others in the upper Great Lakes Region, has been done, based entirely upon an interpretation of their present distribution (Peattie, D. C., Rhodora 24: 57-70, 80-88; 1922., McLaughlin, W. T., Ecol. Mon. 2: 335-383; 1932, and Anderson, E., Rhodora 35: 154-160; 1933). The appearance of these Coastal Plain plants in the Great Lakes Region at an early post glacial date seems very probable, but only since the discovery of the submerged peat beds in Lake Superior is it possible to reconstruct a picture of the ecological conditions of early Glacial Lake Nipissing time and to state definitely what plants then existed in northern Wisconsin. An examination of the largest sample of peat, which is approximately eighteen inches square and four inches thick, shows that it is of a type formed in comparatively still shallow water. About one-half of the thickness of the sample is made up of organic mud, throughout which occur fragments of plant and animal tissues. This portion of the sample is evidently a deeper water deposit than the other half which contains organic tissues in greater abundance and perfection. It seems reasonable to consider the latter as the upper side, but considering the history of the region it is impossible to state definitely. The largest sample was separated arbitrarily into three horizons, and examined both macroand microscopically for fossils. The horizon con-

Palynologic and Plant Compression Evidence for Desmoinesian-Missourian (Pennsylvanian) Series Boundary in Northeastern Oklahoma: ABSTRACT

Palynologic and plant-compression-bearing coal and shale deposits in Tulsa County (northeast Oklahoma) contain floristic evidence for separating the Desmoinesian and Missourian Series at the base of the Checkerboard sandstone (upper Seminole Sandstone). Three coal seams, Dawson (below), Seminole, and Checkerboard, were formerly placed in the Missourian Series. The two lower seams and their associated shales and sandstones are here removed to the Desmoinesian Series. Dawson coals contain approximately 42% Thymospora pseudothiessenii spores and 17% those of Lycospora sp., whereas the Seminole coals contain none of the former and only 1% of the latter. Sphenopsid spores increase from 4% in the Dawson to 25% in the Seminole. Filicineae and Pteridospermae palynomorphs are 65% n the Dawson and 37% in the Seminole. More abundant in the Seminole are the genera Endosporites, Calamospora, Triquitrites, and Laevigatosporites. Checkerboard coals and shales contain the Missourian genera Centonites, Trivolites, Plicatisporites, and Tuberculatosporites. Compression floras associated with the Dawson and Seminole coals contain only 9 known species of which Calamites suckowii, Annularia stellata, Pecopteris pseudovestita(?), Alethopteris serlii, and Neuropteris scheuchzerii are common. The Checkerboard shales contain possibly 29 species. The brachiopod, Mesolobus mesolobus, a Desmoinesian Series invertebrate, is present in shale above the Dawson coal, giving further support to the removal of that unit from the Missourian to the Desmoinesian Series. End_of_Article - Last_Page 2120------------

Palynology and Determination of Ancient Environments: ABSTRACT

Determination of ancient environments by the palynological approach utilizes principles derived from End_Page 283------------------------------ neoecology and from statistical analyses of palynological assemblages. The environmental factors generally sought are physiography, hydrography, temperature, moisture, and substrate. Their determination involves an analysis of fossil origin, preservation, identification, association, relative abundance, and successional occurrence. Palynological fossils in a deposit are commonly derived from more than one ecology and are transported to the place of burial by gravity, wind, water, or some organic vehicle. The lithofacies in which the fossils occur are indicative of the environment of preservation and, in many cases, of the physiographic-hydrographic relations. Identifications of palynomorphs can be made at the phyla level and are valid paleoecological indicators but, with narrower taxo omic recognition, the fossils become increasingly useful in environmental studies. Specific determinations and natural-affinity associations give the best paleoecological criteria for the recognition of distinct environments. Consistent association of certain palynomorph species may be indicative of certain ecological conditions, and their relative abundance can indicate the stage of regional or local environmental development. Relative abundance, however, must not be construed as indicating the absolute abundance of the parent plant or animal from which the palynomorphs were derived. The abundance of individual fossils observed may be governed by the number of spores, pollen, statoblasts, etc. produced by the parent organism, manner and distance of transport to the place of burial, type of preservation, diagenesis of the sediments, and techniques of recovery from the rock for study. Successional stages of palynological assemblages in a stratigraphic section are related to many factors and, where these are recognized, the successional stages can indicate environmental conditions not otherwise apparent. Pleistocene paleoecological studies give clues to techniques that may be used in Tertiary and Upper Mesozoic investigations. This is especially true if the fossils have recognizable natural affinities. When dealing with Paleozoic and Lower Mesozoic palynomorphs there are problems of organic evolution. These make environmental determinations difficult, and more empirical ecological techniques are required than with the younger fossils. Although the resulting environmental conclusions are mainly hypothetical, this information has been found useful in biostratigraphic studies. End_of_Article - Last_Page 284------------