Top 10 Landmark Papers in Paleontology "Tools"

Applin, E. R., Ellisor, A. E. and Kniker, H. T., 1925. Subsurface stratigraphy of the coastal plain of Texas and Louisiana. AAPG Bulletin V. 9: 79-122.

This landmark paper applied subsurface foraminiferal biostratigraphy for correlation and age calibration on the U.S. Gulf Coast that led to the extensive biozonation used today.   

Significantly, it definitively established the value of foraminifera in subsurface stratigraphic correlation, demonstrating that benthic foraminifera data, integrated with wireline logs correlations, could create a successful stratigraphic framework.  Prior to this time, geologists had been correlating with lithologies interpreted from well logs only.  This was difficult in coastal areas with rapid facies changes represented by repetitive sands, muds, and occasional limestones.  The authors described diagnostic species along with their "faunal" or assemblage zones which they termed the Marginulina, Heterostegina, and Discobis zones. 

As Howe (1959, p. 511) states in his review paper on the history of micropaleontology: "Credit for the resolution which took place in the use of foraminifera properly goes to three ladies, Esther Richards Applin [Rio Bravo Oil Company], Alva C. Ellisor [Humble Oil and Refining] and Hedwig T. Kniker [The Texas Company].  Their paper on the subsurface stratigraphy of the coastal plain of Texas and Louisiana (1925) had been presented before the Annual Meeting of the American Association of Petroleum Geologists in Shreveport, Louisiana and the discussion which followed opened the eyes of oil company executives."

A Wikipedia article on Ester Applin, notes that in 1921 she presented a paper at a meeting in Amherst, Massachusetts, stating her theory that microfossils could be used in oil exploration, specifically for the dating of the rock formations in the Gulf of Mexico region. Her theory was disputed by a University of Texas at Austin professor , but the subsequent success of age correlations and biofacies analysis clearly supports Applin's theory.  

Applin remained with Rio Bravo until 1927, continuing to lead the use of micropaleontology in the oil industry. She later went to work alongside her husband at the United States Geological Survey, with the task of correlating the oil fields of East Texas, across the southeastern United States, and into Florida, using micropaleontology and other methods.

Kleinpell, R. M., 1938. Miocene stratigraphy of California. AAPG, Tulsa, Oklahoma: 450.

This seminal publication was a major advancement in unraveling the complex stratigraphy of the hydrocarbon basins in California. Kleinpell's focus was benthic foraminiferal biostratigraphy. Benthic foraminifera were the most conspicuous microfossils in well samples of marine deposits and their application as a correlation tool in the California "oil patch" was still in its infancy when Kleinpell began working on his dissertation in 1931. He used these fossils to develop a biostratigraphic framework for the California Miocene that served as the major reference for most micropaleontologists working on the West Coast for many years. The Miocene section was of particularly interest to the oil industry because it consisted predominantly of the Monterey Shale, a geographically extensive source-and-reservoir rock unit. Kleinpell's work was strongly influenced by fieldwork with his older brother William (an oil company geologist), his fellow Stanford student Hollis Hedberg, whose name later became synonymous with American stratigraphic principles, and biostratigraphic methods of the 19th Century German geologist Albert Oppel, who developed a Jurassic ammonite zonation for Europe. After completing his dissertation, Kleinpell applied the principles set forth in his dissertation to his consulting work in the oil industry with considerable success.  He became widely recognized as the state's leading expert on foraminifera for correlation.

Kleinpell (1938) reflects the extensive taxonomic and biostratigraphic familiarity Kleinpell had with the benthic microfauna. He used this knowledge to formulate a zonation that emulated what Oppel had done with ammonites. Kleinpell divided the Miocene into six stages named for their respective type localities, which in turn were divided into 15 zones, each bearing the name of a prominent species and most being defined by the first appearance of a species at its base and the last appearance of a species at its top. Which and how many of the diagnostic species had to be present to identify a zone was a matter of subjectivity. In essence, each zone was a type of range zone, later termed "Oppel Zone", characterized by the occurrence of certain species within the interval, regardless of their associations in individual assemblages. This was the only viable means for interbasinal correlation of benthic faunas in the Miocene of California, and Kleinpell's application of it received worldwide recognition.

In 1946, Kleinpell joined the Department of Paleontology at the University of California in Berkeley where he supervised Standish Mallory's complementary and similar dissertation on the California Paleogene, which in 1959 was also published in book form by the AAPG. This completed the benthic foraminiferal framework for the California Cenozoic as Natland (1952, 1957) had already named The Pliocene-Pleistocene stages incorporating the zones that had been defined by Wissler (1943).

Imperfections of the California benthic foraminiferal composite scheme were becoming increasingly evident as micropaleontologists often had difficulty applying both the taxonomic and zonal concepts of its authors. Each stage was described from its type locality in one depositional basin, so interbasinal correlations were often problematic. Beginning in the early 1970s, more accurate planktic biostratigraphies, specifically those of calcareous nannoplankton and diatoms, revealed that Kleinpell's stages were plagued by time transgressions and overlaps. It also became evident that they could not be used to correlate two different depositional environments, which supported Natland's long held conviction that all of the benthic stages were based on paleoenvironmental changes that varied in time and space. Nevertheless, applications of the benthic foraminiferal framework for California led to the recovery of billions of barrels of oil and its stage names are engraved in the regional geologic vernacular.

Martini, E., 1971. Standard Tertiary and Quaternary calcareous nannoplankton zonation. In Farinacci, A. (Ed.), Proceedings. 2nd International Conference Planktonic Microfossils Roma: Rome (Ed. Tecnosci.), 2: 739-785.

Dr. Erlend Martini published the first compilation of Tertiary and Quaternary nannofossil assemblages and stratigraphic ranges based on his own research, (Martini (1970), Martini and Worsley (1970) and from zonations proposed by others, most notably Hay et al. (1967), Bramlette and Wilcoxon (1967), and Gartner (1969). Martini's compilation provided a comprehensive framework of letter-number designations NP 1-25 and NN 1-21 and established zonal boundary definitions. This zonation scheme was quickly and widely adopted and is still considered the worldwide "standard" nannofossil zonation most referred to in biostratigraphic research and applications.  Martini included useful range charts of the zone-defining species, charts comparing his zones to foraminifera and silicoflagellate zonations, and photographic plates of the key zonal nannofossil taxa. 

While a few taxa which define Martini's (1971) original zonal boundaries are not widely identified or have proven to be diachronous, most have stood the test of time in broad geographic application. Several amendments or additions have been proposed to improve the utility of the original 1971 zonation, and a second, competing nannofossil zonation by Okada and Bukry (1980), based on low latitude nannofloral assemblages, is preferred by some biostratigraphers.  Martini (1971), however, standing as the original Cenozoic framework, has been largely adopted by investigators in the DSDP, ODP and IODP research programs, and as such, has broadened and expanded the application of calcareous nannofossils as a fundamental biostratigraphic tool for worldwide deepwater marine age-based correlations.

Hardenbol, J. and Berggren, W. A., 1978.  A new Paleogene numerical time scale. AAPG Studies in Geology V. 6: 213-234.

This paper discusses in depth the relationship of Paleogene stage stratotypes of Europe to a chronostratigraphic framework with global applicability thus facilitating numeric basin modeling. The European stratotypes represent the formal basis for relating time and rock units of the Paleocene, Eocene and Oligocene. Most significantly, Hardenbol and Berggren (1978) correlated biozonations of planktic foraminifera and calcareous nannoplankton established in these stratotypes to magnetic polarity history and radiometric ages. The authors accomplished this by drawing on the global results of the Deep Sea Drilling Project. They were then able to provide a robust chronostratigraphy that was applicable at mid to low latitudes around the globe.

Hardenbol and Berggren (1978) was published at the same time that stratigraphic paradigms were shifting through the development and application of "Exxon-style" sequence stratigraphy. These authors were the first to use the multi-fossil group approach using microfossils instead of the invertebrate macrofossils previously used to define biozonations in the European stratotype sections. The high-resolution chronostratigraphy allowed the newly emerging techniques of basin modeling and geohistory to be applied to the Paleogene with improved resolution.
The 1978 work was augmented by the publication of a further-refined scheme in Berggren et al. (1995) that was the standard chronostratigraphy for the Paleogene until publication in 2012 of new time scales and refinements by Gradstein et al. (2012, listed above).

Natland, M. L., 1933. The temperature and depth ranges of some Recent and fossil foraminifera in the southern California region. Scripps Institute of Oceanography, Bulletin, Technical Series V. 3, N. 10: 225-230.

Natland's (1933) paper is fundamental to micropaleontology because it was the first to show that benthic foraminifera are sensitive environmental indicators, and conversely, that the environment exercises primary control on their stratigraphic distribution. Focusing on foraminiferal depth assemblages and using the present as key to the past, Natland designed a study that became a model for others of its kind.  He and a colleague collected 153 bottom samples in the channel between Long Beach and Santa Catalina Island, recording the bottom depth and temperature at each station. He augmented that collection with a dozen samples from greater depths in the region giving him a sample set ranging from an ebb-tide depth of one foot in a brackish lagoon to more than 8,000 feet. He showed that foraminiferal assemblages changed in accordance with the decrease in temperature that accompanied increasing depth. Natland divided the faunal distribution into five "life-zones", each represented by characteristic species. These distinct groups are what we now refer to as biofacies. He then applied his modern foraminiferal data to interpret a Neogene sequence exposed in Hall Canyon near Ventura.  His study indicated that the lowest beds were deposited in the coldest water, and there was a gradual warming from there to the top of the section. Natland was uncertain if the warming was entirely from shallowing, so, unlike those who followed in his footsteps, he refrained from correlating the interpreted water temperatures with depth.

Natland (1944) also recognized mixed assemblages of warmer (shallow) water forms with cooler (deep) water forms, leading him to explore the sedimentary dynamics off California, and he later recognized the major role that was played by turbidity currents (Natland and Kuenen, 1951; Natland, 1957). Those investigations have been vital to our modern understanding of deep-water gravity-flow deposition, which is now of particular importance in the exploration for oil in many parts of the world.

Natland's work had a profound influence on foraminiferologist Orville Bandy at the University of Southern California. At a time when most foraminiferal research was taxonomic or biostratigraphic, Bandy and his students used Natland's work as a springboard from which they delved into ecological and paleoecological studies.  These included the first biofacies maps on stratigraphic horizons (e.g., Bandy and Arnal, 1960; 1969), several of the earliest studies using biofacies to map polluted environments (Bandy et al., 1964a, 1964b, 1965a, 1965b), and the first thorough compilation of regional biofacies and their integration with the environmental factors that have shaped them throughout the Cenozoic (Ingle, 1980).

Phleger, F. B. and Parker, F. L., 1951. Ecology of foraminifera, northwest Gulf of Mexico, Parts I & II. The Geological Society of America Memoir 46 Part I: 1-88 and Part II: 1-64.

Phleger and Parker (1951) was a major advancement in the study of living foraminifera that fundamentally set the ecology and environmental/bathymetric zonation standard in the Gulf of Mexico. This work also established a foundation for paleowater-depth biofacies currently used by biostratigraphers in the Gulf of Mexico and in other basins worldwide. Of course, information from papers published since 1951 and studies done internally by oil company paleontologists active in the Gulf of Mexico and world-wide has been used to refine this work for regional application. But, Phleger and Parker (1951) is the gold standard upon which these subsequent works were constructed.

Six bathymetric zones were set up from deep middle Neritic (80m) to lower most Bathyal to Abyssal (2000m) based on populations of benthic foraminifera found in 550 bottom samples, and 55 submarine cores from the northwest Gulf of Mexico collected in 1947.

The overall impact of this paper demonstrated how foraminiferal assemblages could be interpreted and showed the value of using and refining ecologic/bathymetric zones for biofacies and sedimentary analysis. The ratio of planktic to benthic foraminifera observed in samples helped initiate the analysis of relative rates of sedimentation.

Some refining works published since this landmark paper (listed alphabetically) include Albers, et al. (1966), Denne and Sen Gupta (1993), Pflum and Frerichs (1976), Poag (1981), Poag (2015), Tjalsma and Lohmann (1983), Van Morkhoven et al. (1986) and Walton (1964).

Bandy, O.L. and Arnal, R. E., 1960. Concepts of foraminiferal paleoecology. AAPG Bulletin V. 44, N. 12: 1921-1932.

This classic paper pioneered the application of foraminiferal biofacies in basin analysis.  Current studies that integrate biofacies occurrence in combination with seismic stratigraphic systems tract analysis provides a high confidence interpretation of depositional environments.

Bandy and Arnal (1960) synthesized previously published studies on modern foraminiferal biofacies to develop and test multiple criteria in order to paleobathymetrically analyze ancient basins. They recognized seven criteria of greatest importance: (1) the general trends in species abundance and total benthic specimens relative to water depth and distance from shore; (2) the utility of porcelaneous foraminifera as indices of nearshore conditions; (3) the abundance of simple-walled agglutinated species in some brackish areas vs. the complexly structured tests of other agglutinated species in deep water; (4) the abundance of planktic foraminifera on the outer shelf and upper slope; (5) the validity of using fossil homeomorphs of modern species as paleoenvironmental indicators; (6) the recognition of displaced species; and (7) the utilization of upper-depth limits of the deepest-dwelling species in an assemblage to indicate the minimum depth of deposition.

Bandy and Arnal (1960) used these seven occurrence patterns as internal checks to validate their paleobathymetric maps of California's petroliferous San Joaquin Basin during the Luisian Stage (middle Miocene). The latter previewed their much more extensive analysis of this basin based on more than 5,000 core samples (Bandy and Arnal, 1969). Bandy and Arnal's maps appear to be the first basin-wide paleobathymetry maps based on subsurface biofacies data. Their 1960 paper also showed how paleobathymetric changes between two successive time-slices (beginning and end of the Luisian) can be used to quantify patterns of subsidence and uplift, which are key components for understanding relationships between oil fields and basin development.

The Bandy and Arnal (1960) paper has been one of the most influential contributions to California micropaleontology.  Not just did it lay the groundwork for their later studies Bandy and Chierici (1966), Bandy and Arnal (1969), and Arnal (1976), it inspired others (e.g., Ingle, 1967, 1980; Lagoe and MacDougall, 1986; Finger et al., 1990; Olson, 1990) to adopt and further investigate the micropaleontologic criteria they recognized as useful tools in paleoenvironmental analysis.

Ziegler, W., 1962. Taxonomie und phylogenie Oberdevonischer conodonten und ihre stratigraphische Bedeutung (Taxonomy and phylogeny Upper Devonian conodonts and their stratigraphic significance). Abhandlungen des Hessischen Landesamtes für Bodenforschung 38: 166.

The need for biostratigraphically-constrained correlation of Paleozoic-aged sediments is no less than for those of Mesozoic and Cenozoic age. Klemme and Ulmishek (1991) attributed approximately 25% of recoverable oil and gas reserves to three Paleozoic source rock intervals; Silurian, Upper Devonian, and Pennsylvanian-Lower Permian.  These intervals are now being intensively investigated as resource plays, both in the United States (e.g. Bakken Shale) and internationally. Key conventional hydrocarbon reservoir intervals are also of Paleozoic age. The giant gas fields of the Khuff Formation and its equivalents in the Middle East are one such example.  There is therefore a critical need for biostratigraphic tools to provide correlation and age calibration of basin models. Fossils of conodonts, acritarchs, chitinozoa and fusulinid foraminifera provide such calibration.

One of the earliest Paleozoic biochronologies was Willi Ziegler's (1962) monograph establishing the standard for Devonian conodont biostratigraphy that remained in force until 1990 when it was updated by Ziegler and Sandberg (1990). Conodonts are phosphatic teeth-like structures of pelagic 'eel-like' organisms abundant in Paleozoic marine sediments.  Because of their rapid evolution, conodonts have great biostratigraphic utility. Working principally on sections in Germany and Belgium, but considering stratigraphic distribution in North America and elsewhere, Ziegler defined a series of zones based on evolutionary inceptions, but with each zone characterized by a set of faunal elements (assemblage). The zonation devised by Ziegler, and now updated, includes 32 zones for the Late Devonian that have a typical duration of c. 500,000 years or less. This stratigraphic precision has proven to be a valuable tool for both local and inter-continental correlation of Devonian sediments and is one of the reasons that the event stratigraphy and eustasy of the Devonian period is so well understood (House & Ziegler, 1997), and Devonian stratotype stages were amongst the first formally defined (Becker et al., 2012).  

Germeraad, J. H., Hopping C. A. and Muller, J., 1968. Palynology of Tertiary sediments from tropical areas.  Palaeobotany and Palynology Review 6: 189-348.

Germeraad et al. (1968) presents the results of nearly twenty years of intensive study of pollen and spore content in Tertiary sediments from wells and outcrops across the Tropics. It shows how to apply palynology as a tool for age dating and correlation, and establishing palynology biostratigraphic zones based on the stratigraphic and geographical extent from a selection of 49 tropical pollen and spore species.

The zonation, from the Maastrichtian to the Pleistocene, includes six Pantropical Zones that can be recognized from the Caribbean, through tropical Africa and across South East Asia. Within the same palynological zonal framework, there is a further refined Transatlantic zonation and regional zonations for the Caribbean and Borneo. Included also as supporting information are the palynological correlation panels across northern and western Venezuela, Trinidad, and Colombia, together with the distribution charts from key sections in Venezuela, Trinidad, and Nigeria.

The Germeraad et al. (1968) zonation framework is so robust that after almost 50 years since its publication (1968 – 2016), it is still useful and a key reference for palynologists working tropical terrestrial floras.  While the zonation framework is the most obvious contribution of the paper, the authors extended the application of palynology as a stratigraphic tool in industry and academia through: 1) demonstration of the importance of quantitative and statistical analysis of pollen and spore assemblages for zonation recognition in the tropics, 2) discussed the transport and climate effects on the final characteristics of the assemblages, and 3) proposed botanical affinities for many of the key species to support their stratigraphic significance and geographic distribution. For all of the above, this is a unique and timeless contribution to the science of biostratigraphy and the value of "terrestrial" palynology in biostratigraphy, especially for the oil and gas industry.

Last but not least, this paper builds on Kuyl et al. (1955), which is a pioneering and historic paper that demonstrates the application of palynology in oil exploration, and Muller (1959) dealing with the distribution of palynomorphs in recent deltaic sediments. From the many papers that have been published afterwards that partially address in more detail the palynology of specific tropical areas, it is also relevant to mention Muller, Di Giacomo and Van Erve (1987).