Burning peat and reworking loess contribute to the formation and evolution of a large Carolina-bay basin

2012 ◽  
Vol 77 (1) ◽  
pp. 171-181 ◽  
Author(s):  
Antonio B. Rodriguez ◽  
Matthew N. Waters ◽  
Michael F. Piehler

Carolina bays are nearly ubiquitous along ~ 1300 km of the North American Atlantic Coastal Plain, but relatively few bays have been examined in detail, making their formation and evolution a topic of controversy. The Lake Mattamuskeet basin, eastern North Carolina, USA, is a conglomeration of multiple Carolina bays that form a > 162 km2 lake. The eastern shoreline of the lake is made up of a 2.9-km-wide plain of parabolic ridges that recorded rapid shoreface progradation. The lower shoreface deposit contains abundant charcoal beds and laminae dated 6465–6863 cal yr BP, corresponding with initiation of a lacustrine environment in the eastern part of the lake. A core from the western part of the lake sampled a 1541–1633 cal yr BP charcoal bed at the base of the lacustrine unit, indicating formation of this part of the basin postdates the eastern basin. Lake Mattamuskeet has no relationship to the Younger Dryas or a linked impact event because rim accretion significantly postdates 12,000 cal yr BP. The shoreline progradation, and association of charcoal beds with the oldest lake sediment in both main parts of the basin, suggest that fire and subsequent hydrodynamic processes were associated with initial formation of these Carolina bays.

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9284
Author(s):  
Jon Baskin ◽  
Edwin Dickinson ◽  
John DuBois ◽  
Henry Galiano ◽  
Adam Hartstone-Rose

Miocene terrestrial mammals are poorly known from the Atlantic Coastal Plain. Fossils of the Order Carnivora from this time and region are especially rare. We describe a carnivoran mandible with a p4 from the late Oligocene or early early Miocene Belgrade Formation in Jones County, North Carolina. Comparisons are made with carnivoran jaws with similar premolar and molar lengths from the late Oligocene and Miocene of North America and Eurasia. These indicate that the North Carolina jaw is assignable to the Ailuridae, a family whose only living member is the red panda. The jaw is tentatively referred to Amphictis, a genus known elsewhere from the late Oligocene and early Miocene of Europe and the early Miocene (Hemingfordian) of North America. The North Carolina mandible compares best with the late Oligocene (MP 28) Amphictis ambiguus from Pech du Fraysse, France, the oldest known member of the Family Ailuridae, and with the early Miocene (MN 1–MN 2a) A. schlosseri from southwestern Germany. This identification is compatible with a late late Arikareean (Ar4, early Miocene, MN 2-3 equivalent) age assignment for the other terrestrial mammals of the Belgrade Formation.


2007 ◽  
Vol 85 (9) ◽  
pp. 822-849 ◽  
Author(s):  
Peter A. Siver ◽  
Lee Camfield

During an investigation of freshwater diatoms from highly acidic ponds scattered along the Atlantic Coastal Plain of North Carolina we encountered a large number of specimens from the genus Stenopterobia . All of the specimens were representative of straight, not sigmoidal-shaped, taxa and collectively ranged in length from ca. 10 µm to over 200 µm. In the process of making species determinations we examined type material for four species of Stenopterobia originally described by Lewis (1864) from Saco Pond, a small spring-fed waterbody nestled in the White Mountains of New Hampshire. The four species, Stenopterobia baileyi (Lewis) Brébisson ex Van Heurck, Stenopterobia anceps (Lewis) Brébisson ex Van Heurck, Stenopterobia delicatissima (Lewis) Brébisson ex Van Heurck, and Surirella intermedia Lewis (=Stenopterobia curvula (W. Smith) Krammer), were originally placed by Lewis within the genus Surirella. We examined seven permanent slides archived at the Academy of Natural Sciences of Philadelphia that contained material collected by Lewis. In addition, we collected new material from Saco Pond, including a sediment core, and examined these samples using SEM. We also examined type material for another species, Stenopterobia cuspidata (Hustedt) Vyverman, using SEM. We concluded that the North Carolina collections contained five species, two described as new ( Stenopterobia gracilis sp. nov. Siver & Camfield and Stenopterobia fusiformis sp. nov. Siver & Camfield), two representing organisms originally described by Lewis (S. baileyi and S. delicatissima), and the fifth recently described from Cape Cod ( Stenopterobia pseudodelicatissima Siver & Hamilton). New characters, including externally capped areolae, valve face coverings, and laterally opened girdle bands, are described for the genus. Lastly, lectotypes for three of Lewis’ taxa were selected.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6088 ◽  
Author(s):  
Robert W. Boessenecker ◽  
Dana J. Ehret ◽  
Douglas J. Long ◽  
Morgan Churchill ◽  
Evan Martin ◽  
...  

The extinct giant shark Otodus megalodon is the last member of the predatory megatoothed lineage and is reported from Neogene sediments from nearly all continents. The timing of the extinction of Otodus megalodon is thought to be Pliocene, although reports of Pleistocene teeth fuel speculation that Otodus megalodon may still be extant. The longevity of the Otodus lineage (Paleocene to Pliocene) and its conspicuous absence in the modern fauna begs the question: when and why did this giant shark become extinct? Addressing this question requires a densely sampled marine vertebrate fossil record in concert with a robust geochronologic framework. Many historically important basins with stacked Otodus-bearing Neogene marine vertebrate fossil assemblages lack well-sampled and well-dated lower and upper Pliocene strata (e.g., Atlantic Coastal Plain). The fossil record of California, USA, and Baja California, Mexico, provides such an ideal sequence of assemblages preserved within well-dated lithostratigraphic sequences. This study reviews all records of Otodus megalodon from post-Messinian marine strata from western North America and evaluates their reliability. All post-Zanclean Otodus megalodon occurrences from the eastern North Pacific exhibit clear evidence of reworking or lack reliable provenance; the youngest reliable records of Otodus megalodon are early Pliocene, suggesting an extinction at the early-late Pliocene boundary (∼3.6 Ma), corresponding with youngest occurrences of Otodus megalodon in Japan, the North Atlantic, and Mediterranean. This study also reevaluates a published dataset, thoroughly vetting each occurrence and justifying the geochronologic age of each, as well as excluding several dubious records. Reanalysis of the dataset using optimal linear estimation resulted in a median extinction date of 3.51 Ma, somewhat older than a previously proposed Pliocene-Pleistocene extinction date (2.6 Ma). Post-middle Miocene oceanographic changes and cooling sea surface temperature may have resulted in range fragmentation, while alongside competition with the newly evolved great white shark (Carcharodon carcharias) during the Pliocene may have led to the demise of the megatoothed shark. Alternatively, these findings may also suggest a globally asynchronous extinction of Otodus megalodon.


Zootaxa ◽  
2012 ◽  
Vol 3194 (1) ◽  
pp. 51 ◽  
Author(s):  
STEVEN FEND ◽  
DAVID R. LENAT

Three new species of Lumbriculidae from southeastern North America are attributed to Eclipidrilus Eisen. All are small worms (diameter 0.2–0.5 mm), having semi-prosoporous male ducts with the atria in X, and spermathecae in IX. Eclipidrilus breviatriatus n. sp. and E. microthecus n. sp. have crosshatched atrial musculature, similar to some E. (Eclipidrilus) species, but they differ from congeners in having small, compact spermathecal ampullae. Eclipidrilus macphersonae n. sp. has a single, median atrium and spermatheca. The new species have been collected only in Sandhills and Middle Atlantic Coastal Plain streams of North Carolina.


2010 ◽  
Vol 33 (2) ◽  
pp. 121-173 ◽  
Author(s):  
Thomas M. Cronin

Upper Pleistocene deposits from 21 localities in Maryland, Virginia, South Carolina, North Carolina, and northern Florida yielded 77 ostracode species; virtually all are living today in brackish and marine water. Five late Pleistocene ostracode biofacies signifying lagoonal, oyster bank, estuarine, open sound, and inner sublittoral environments were delineated using Principal Coordinate Analysis. During the late Pleistocene, the Lagoonal and Oyster Bank Biofacies predominated in the Chesapeake Bay area, whereas east-central North Carolina was characterized by an Open Sound Biofacies similar to that in Pamlico Sound today. The Inner Sublittoral Biofacies was present in southeastern Virginia and along the South Carolina coast. The Estuarine Biofacies was found only in the Chesapeake Bay region. Paleoclimates were inferred by a comparison of Holocene and late Pleistocene ostracode zoogeography; apparently the climate during the late Pleistocene was as warm as, and in some areas warmer than at the same latitudes today. Ostracode species are illustrated by scanning electron photomicrographs Cyprideis margarita, Neocaudites atlan-tica, and Microcytherura norfolkensis are described as new species.


Sign in / Sign up

Export Citation Format

Share Document