Journey Somewhat Nearer to the Center of the Earth: fossils in cores

Most of the time, when people are looking for fossils, they find them at the surface or just below. However, this is hardly the limit of where they can be found. After all, a fossiliferous formation found at the surface in one location may be buried hundreds to thousands of feet beneath other rocks and sediments somewhere else, and it doesn't stop being fossiliferous just because it's buried that far down. It just becomes much less accessible. We can get glimpses of the buried fossils through core samples.

Fossils are rather frequently found in cores taken in sediments and sedimentary rock. The catch is they tend not to be types of fossils that people generally get excited about. For that matter, they are frequently fossils that can't even be identified with the naked eye: foraminifera, diatoms, radiolarians, ostracodes, pollen, spores, and so on. This is not too surprising when you think about it, microfossils being both very abundant and small enough to be safely captured in your typical core sample. Larger fossils also usually belong to particularly abundant categories, such as invertebrate shells, invertebrate trace fossils, and plant debris.

Where do these fossiliferous cores come from? Some borings are from infrastructure work, such as planning foundations, opening water wells (recall Fort McHenry and Fort Monroe), or, in the case of Stauffer's microfossils from the University of Minnesota campus, sinking a heating shaft for Northrup Auditorium (Stauffer 1930). These borings don't typically go down several hundred or thousands of feet (Fort Monroe excepted, as that one had engaged the honor of the War Department), as in general the only human infrastructure at those depths consists of mines and supervillain lairs. The petroleum industry is another major source of borings, which can and do go to those depths. In these cases, recovering fossils is part of the point, because they are useful for understanding the stratigraphy and therefore the resource potential. Finally, there are borings made for more purely scientific purposes. These can be short (10 feet or less) or thousands of feet, depending on the question. For example, study of the paleoecology of a lake only requires a core deep enough to capture the thickness of the lake deposits. If you want to look at the stratigraphy of a sedimentary basin, it's a similar principle, but you're probably going to need a substantially longer core. These cores are particularly useful in locations where there are thick surficial deposits and few outcrops.

One of the most notable well core fossils is a Cretaceous turtle from near Okeechobee, Florida. Florida, as you might suspect, is not noted for its Mesozoic outcrops, and it is extremely unlikely that this deficiency will be changed in human history. (In fact, if it is, human history probably won't extend much beyond the event that brings Mesozoic rocks to the surface there.) This particular fossil, consisting of part of the front of the turtle minus the skull, was recovered back in 1955 at a depth of 9,210 feet (2,810 m) in an exploratory petroleum well (Olsen 1965). Presumably the rest of the turtle is still there, and all you would need to do to retrieve it is to track down the location of the well and sink more of them directly adjacent until you get it. Olsen (1965) also writes of an Ordovician trilobite (Colpocoryphe exsul) recovered from a more manageable 4,628 feet (1,410 m) in Madison County, Florida by another oil company in 1944, indicating different basement topography up by the Georgia border.

Another notable example, also with an oil background, comes from the North Sea, where workers in the Snorre oil field recovered fossils from a core taken through the Upper Triassic Lunde Formation. Aside from microfossils, bioturbation, and such, there was also a cross-section of a dinosaurian long bone, attributed to Plateosaurus (Hurum et al. 2006). Of course, Plateosaurus isn't quite what it was in 2006, but you get the idea. Hurum et al. also mention that fragments of plesiosaur and ichthyosaur bones have been found in offshore drill cores in the region, described "summarily" in Heintz and Sæther (1999).

In my work on National Park Service sites, I've kept track of these records for parks, although there is admittedly little resource management that needs to be done for microfossils recovered, say, 9,000 feet (2,700 m) below the surface. East Coast parks, such as Cape Hatteras National Seashore, Cape Lookout National Seashore, and Fort Pulaski National Monument, tend to be the most pockmarked. Cape Hatteras National Seashore holds the record among parks for most fossil species named from core samples with 23, representing Mesozoic and Cenozoic forams and ostracodes (see Jordan and Applin 1952 and Swain 1952a and 1952b). This is thanks to the Esso #1 petroleum test well, drilled in 1946 within easy walking distance of the Cape Hatteras lighthouse to a depth of 10,019 feet below sea level (3,053.8 m). Cape Hatteras also holds the record for deepest holotype, for the foram Anchispirocyclina henbesti Jordan and Applin (1952) recovered from a depth of 9,115 to 9,116 feet (2,778 to 2,779 m). In other words, if you hike at a 3 mph clip, that would be about a 35-minute walk.

This is Esso #1, 10,000+ feet of strata; definitely one to click to embiggen! This comes from sheet 2 of Weems et al. (2019), a USGS report.

The champion for subterranean sampling in volume, though, is affiliated unit New Jersey Pinelands National Reserve, which seems like it may be made up mostly of holes when I look back at my notes. As a token of its weighty record, a partial list of relevant references is included at the end; for the sanity of those not inclined to acquiring a comprehensive understanding of the geological cores of southern New Jersey, the list is below the regular references. The longest cores are not quite as epic as the Cape Hatteras well, being more in the couple thousand foot range but still quite respectable. Why the compulsion to core southern New Jersey? Well, for one thing, with the expansion of interest in the end-Cretaceous extinction in the past few decades, it turns out that Atlantic Coastal Plain sediments of the proper age are a good target to look for the effects of the catastrophe. They just happen to be often buried beneath significant amounts of younger Atlantic Coastal Plain sediments. The Coastal Plain sedimentary wedge is also a very good sedimentary record of the Cretaceous and Cenozoic in general, with almost two dozen formations from the mid-Cretaceous Potomac Group to the late Quaternary Cape May Formation, about 100 million years with few lengthy interruptions (the Pliocene into the late Pleistocene, and that's about it). The cores contained robust fossil assemblages for these formations. The great majority yielded wood and/or lignite, pollen, shells (usually bivalves), invertebrate burrows and bioturbation, forams, nannofossils (e.g., coccoliths), and diatoms and/or dinoflagellates. Vertebrate specimens were not common but were found in a few formations, primarily teeth of sharks and bony fish. Finally, a third contributing factor to the wealth of cores is the abundance of bogs, marshes, and lakes that can be sampled for late Quaternary data; these can be considered a separate category from the deeper borings made through the Coastal Plain wedge.

References

Jordan, L., and E. R. Applin. 1952. Choffatella in the Gulf Coast regions of the United States and description of Anchispirocyclina n. gen. Contributions from the Cushman Foundation for Foraminiferal Research 3(1): 1–5.

Swain, F. M. 1952a. Ostracoda from wells in North Carolina. Part 1, Cenozoic Ostracoda. U.S. Geological Survey, Washington, D.C. Professional Paper 234A.

Swain, F. M. 1952b. Ostracoda from wells in North Carolina. Part 2. Mesozoic Ostracoda. U.S. Geological Survey, Washington, D.C. Professional Paper 234B.

Heintz, N., and T. Sæther. 1999. Fiskeøgle på Haltenbanken. Geonytt 1: 22–23.

Hurum, J. H., M. Bergan, R. Müller, J. P. Nystuen, and N. Klein. 2006. A Late Triassic dinosaur bone, offshore Norway. Norwegian Journal of Geology. 86: 117–123.

Olsen, S. J. 1965. Vertebrate fossil localities in Florida. Florida Geological Survey, Tallahassee, Florida. Special Publication 12.

Stauffer, C. R. 1930. Conodonts from the Decorah Shale. Journal of Paleontology 4(2): 121–128.

Weems, R. E., J. Self-Trail, and L. E. Edwards. 2019. Cross section of the North Carolina Coastal Plain from Enfield through Cape Hatteras. U.S. Geological Survey, Reston, Virginia. Open-File Report 2019-1145.

Pinelands references

Andrews, G. W. 1987. Miocene marine diatoms from the Kirkwood Formation, Atlantic County, New Jersey. U.S. Geological Survey, Reston, Virginia. Bulletin 1769.

Aurisano, R. W. 1984. Three new dinoflagellate species from the subsurface Upper Cretaceous Atlantic Coastal Plain of New Jersey. Journal of Paleontology 58(1): 1–8.

Aurisano, R. W. 1989. Upper Cretaceous dinoflagellate biostratigraphy of the subsurface Atlantic Coastal Plain of New Jersey and Delaware, U.S.A. Palynology 13: 143–179.

Aurisano, R., and D. Habib. 1977. Upper Cretaceous dinoflagellate zonation of the subsurface Toms River Section near Toms River, New Jersey. Pages 369–388 in F. M. Swain, editor. Stratigraphic micropaleontology of Atlantic basin and borderlands. Elsevier Scientific Publishing Company, Amsterdam, the Netherlands. Developments in Palaeontology and Stratigraphy 6.

Browning, J. V., K. G. Miller, and L. M. Bybell. 1997. Upper Eocene sequence stratigraphy and the Absecon Inlet Formation, New Jersey coastal plain. Proceedings of the Ocean Drilling Program, Scientific Results 150X: 243–266.

Browning, J. V., P. J. Sugarman, K. G. Miller, N. A. Abdul, M.-P. Aubry, L. E. Edwards, D. Bukry, S. Esmeray, M .D. Feigenson, W. Graf, A. D. Harris, P. J. Martin, P. P. McLaughlin, S. F. Mizintseva, D. H. Monteverde, L. M. Montone, R. K. Olsson, J. Uptegrove, H. Wahyudi, H. Wang, and Zulfitriadi. 2011. Double Trouble site. Proceedings of the Ocean Drilling Program, Initial Reports 174AX (supplement): 1–63.

Bybell, L. M., and J. M. Self-Trail. 1997. Late Paleocene and Early Eocene calcareous nannofossils from three boreholes in an onshore-offshore transect from New Jersey to the Atlantic continental rise. Proceedings of the Ocean Drilling Program, Scientific Results 150X: 91–110.

Christensen, B. A., K. G. Miller, and R. K. Olsson. 1995. Eocene-Oligocene benthic foraminiferal biofacies and depositional sequences at the ACGS #4 borehole, New Jersey coastal plain. PALAIOS 10(2): 103–132.

de Verteuil, L., and G. Norris. 1996. Miocene dinoflagellate stratigraphy and systematics of Maryland and Virginia. Micropaleontology 42(supplement).

Florer, L. E. 1972. Palynology of a postglacial bog in the New Jersey Pine Barrens. Bulletin of the Torrey Botanical Club 99(3): 135–138.

Georgescu, M. D. 2006. Santonian–Campanian planktonic foraminifera in the New Jersey coastal plain and their distribution related to the relative sea-level changes. Canadian Journal of Earth Sciences 43: 101–120.

Gohn, G. S. 1997. Data report: Cretaceous ostracode assemblages in the Island Beach Core, New Jersey coastal plain. Proceedings of the Ocean Drilling Program, Scientific Results 150X: 287–292.

Greller, A. M., and L. D. Rachele. 1983. Climatic limits of exotic genera in the Legler Palynoflora, Miocene, New Jersey, U.S.A. Review of Palaeobotany and Palynology 40: 149–163.

Huber, B. T., R. K. Olsson, and P. N. Pearson. 2006. Taxonomy, biostratigraphy, and phylogeny of Eocene microperforate planktonic foraminifera (Jenkinsina, Cassigerinelloita, Chiloguembelina, Streptochilus, Zeauvigerina, Tenuitella, and Cassigerinella) and Problematica (Dipsidripella). Cushman Foundation Special Publication 41: 461–508.

Miller, K. G., P. J. Sugarman, J. V. Browning, B. S. Cramer, R. K. Olsson, L. de Romero, M.-P. Aubry, S. F. Pekar, M. D. Georgescu, K. T. Metzger, D. H. Monteverde, E. S. Skinner, J. Uptegrove, L. G. Mullikin, F. L. Muller, M. D. Feigenson, T. J. Reilly, G. J. Brenner, and D. Queen. 1999. Ancora site. Proceedings of the Ocean Drilling Program, Initial Reports 174AX (supplement): 1–65.

Miller, K. G., P. J. Sugarman, J. V. Browning, M. A. Kominz, R. K. Olsson, M. D. Feigenson, and J. C. Hernández. 2004. Upper Cretaceous sequences and sea-level history, New Jersey Coastal Plain. Geological Society of America Bulletin 116(3/4): 368–393.

Miller, K. G., P. J. Sugarman, J. V. Browning, R. K. Olsson, S. F. Pekar, T. J. Reilly, B. S. Cramer, M.-P. Aubry, R. P. Lawrence, J. Curran, M. Stewart, J. M. Metzger, J. Uptegrove, D. Bukry, L. H. Burckle, J. D. Wright, M. D. Feigenson, G. J. Brenner, and R. F. Dalton. 1998. Bass River Site. Proceedings of the Ocean Drilling Program, Initial Reports 174AX: 5–43.

Miller, K. G., P. Sugarman, M. Van Fossen, C. Liu, J. V. Browning, D. Queen, M.-P. Aubry, L. D. Burckle, M. Goss, and D. Bukry. 1994. Island Beach site report. Proceedings of the Ocean Drilling Program, Initial Reports 150X: 5–33.

Olsson, R. K., K. G. Miller, J. V. Browning, D. Habib, and P. J. Sugarman. 1997. Ejecta layer at the Cretaceous-Tertiary boundary, Bass River, New Jersey (Ocean Drilling Program Leg 174AX). Geology 25(8): 759–762.

Owens, J. P., L. M. Bybell, G. Paulachok, T. A. Acer, V. M. Gonzalez, and P. J. Sugarman. 1988. Stratigraphy of the Tertiary sediments in a 945-foot-deep corehole near Mays Landing in the southeastern New Jersey Coastal Plain. U.S. Geological Survey, Reston, Virginia. Professional Paper 1484.

Pekar, S. F., K. G. Miller, and R. K. Olsson. 1997. Data report: the Oligocene Sewell Point and Atlantic City formations, New Jersey Coastal Plain. Proceedings of the Ocean Drilling Program, Scientific Results 150X: 81–87.

Perry, W. J., J. P. Minard, E. G. A. Weed, E. I. Robbins, and E. C. Rhodehamel. 1975. Stratigraphy of Atlantic coastal margin of United States north of Cape Hatteras; brief survey. AAPG Bulletin 59(9): 1529–1548.

Petters, S. W. 1976. Upper Cretaceous subsurface stratigraphy of the Atlantic Coastal Plain of New Jersey. AAPG Bulletin. 60(1): 87–107.

Petters, S. W. 1977. Bolivinoides evolution and Upper Cretaceous biostratigraphy of the Atlantic Coastal Plain of New Jersey. Journal of Paleontology 51: 1023–1036.

Petters, S. W. 1977. Upper Cretaceous planktonic foraminifera from the subsurface of the Atlantic Coastal Plain of New Jersey. Journal of Foraminiferal Research 7(3): 165–187.

Poore, R. Z., and L. M. Bybell. 1988. Eocene to Miocene biostratigraphy of New Jersey core ACGS # 4: Implications for regional stratigraphy. U.S. Geological Survey, Reston, Virginia. Bulletin 1829.

Potzger, J. E. 1945. The Pine Barrens of New Jersey: a refugium during Pleistocene times. Butler University Botanical Studies 7(14).

Potzger, J. E. 1952. What can be inferred from pollen profiles of bogs in the New Jersey Pine Barrens. Bartonia 26: 20–24, 26–27.

Rachele, L. D. 1976. Palynology of the Legler Lignite: a deposit in the Tertiary Cohansey Formation of New Jersey, U.S.A. Review of Palaeobotany and Palynology 22: 225–252.

Richards, H. G. 1945. Subsurface stratigraphy of Atlantic Coastal Plain between New Jersey and Georgia. Bulletin of the American Association of Petroleum Geologists 29(7): 885–965.

Richards, H. G. 1947. Invertebrate fossils from deep wells along the Atlantic Coastal Plain. Journal of Paleontology 21(1): 23–37.

Richards, H. G. 1962. Appendix C: New Cretaceous invertebrate fossils from test borings in New Jersey. Pages 199-207 in The Cretaceous fossils of New Jersey, part II. New Jersey Geological Survey, Trenton, New Jersey. Bulletin 61, Part II.

Richards, H. G. 1962. Studies on the marine Pleistocene: Part I. The marine Pleistocene of the Americas and Europe. Part II. The marine Pleistocene mollusks of eastern North America. Transactions of the American Philosophical Society 52(3): 1–141.

Richards, H. G., F. H. Olmsted, and J. L. Ruhle. 1962. Generalized structural contour maps of the New Jersey Coastal Plain. New Jersey Geological Survey, Trenton, New Jersey. Geological Series 4.

Seaber, P. R., and J. Vecchioli. 1963. Stratigraphic section at Island Beach State Park, New Jersey. Pages B102–B105 in Geological Survey research 1963: short papers in geology and hydrology. U.S. Geological Survey, Washington, D.C. Professional Paper 475B.

Sluijs, A., and H. Brinkhuis. 2009. A dynamic climate and ecosystem state during the Paleocene-Eocene Thermal Maximum: inferences from dinoflagellate cyst assemblages on the New Jersey Shelf. Biogeosciences 6: 1755–1781.

Southwick, D. L. 1964. Petrography of the basement gneiss beneath the coastal plain sequence, Island Beach State Park, New Jersey. Pages C55–C60 in Geological Survey Research 1964: Chapter C. U.S. Geological Survey, Washington, D.C. Professional Paper 501-C.

Sugarman, P. J., K. G. Miller, R. K. Olsson, J. V. Browning, J. D. Wright, L. M. De Romero, T. S. White, F. L. Muller, and J. Uptegrove. 1999. The Cenomanian/Turonian carbon burial event, Bass River, NJ, USA: geochemical, paleoecological, and sea-level changes. Journal of Foraminiferal Research 29(4): 438–452.

Van Valkenburg, S. G., D. B. Mason, J. P. Owens, and L. McCartan. 1997. Clay mineralogy of the Cape May, Atlantic City, and Island Beach boreholes, New Jersey. Proceedings of the Ocean Drilling Program, Scientific Results 150X: 59–64.