Erosional and depositional history of the Atlantic passive margin as recorded in detrital zircon fission-track ages and lithic detritus in Atlantic Coastal plain sediments

Eight apatite and two zircon fission-track ages provide evidence of complex Tertiary thermal overprinting by hydrothermal fluids in the Gilmore Dome area. Five ages on apatite from the Fort Knox gold deposit average 41 Ma, one from the Stepovich prospect is 80 Ma, and two from Pedro Dome average 67 Ma. Elevations of these samples overlap but their ages do not, indicating that each area experienced a different thermal history.Ages of apatite from the Fort Knox gold deposit decrease with elevation from 42 to 36 Ma but have data trends indicative of complex cooling. Two ~51 Ma ages on zircon indicate that maximum temperatures approached or exceeded ~180 °C. An alteration assemblage of chalcedony + zeolite + calcite + clay in the deposit resulted from deposition by a paleo-hydrothermal system. The data suggest that the system followed a complex cooling path from > 180 to < 110 °C between 51 and 36 Ma, and that final cooling to below 60 °C occurred after ~25 Ma.The 80 Ma age from Stepovich prospect either resulted from cooling after intrusion of the underlying pluton (~90 Ma) or records postintrusion thermal overprinting sometime after ~50 Ma. The 67 Ma samples from Pedro Dome may also have experienced partial age reduction during later heating. The differences in the data from the different areas and the presence of a late alteration assemblage at Fort Knox suggest that the fluids responsible for heating were largely confined to the highly fractured and porous Fort Knox pluton.

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Oxon Run Parkway: Paleontological resource inventory; supplement to the National Capital Parks-East paleontological resource inventory

10.36967/nrr-2287217 ◽

2021 ◽

Author(s):

Margot Nelson ◽

Michael Antonioni ◽

Vincent Santucci ◽

Justin Tweet

Keyword(s):

Coastal Plain ◽

District Of Columbia ◽

Atlantic Coastal Plain ◽

Natural Area ◽

Original Plan ◽

Resource Inventory ◽

National Capital ◽

Park Service ◽

History Of ◽

Atlantic Coastal

Oxon Run Parkway (OXRN) is a 51-hectare (126-acre) natural area within Washington, D.C. administered by the National Park Service under National Capital Parks East (NACE). The original plan called for a road, slated to follow Oxon Run stream, but this never came to fruition; despite this, the moniker stuck. The majority of the original Oxon Run Parkway is managed by the District of Columbia. The section of Oxon Run Parkway under NPS jurisdiction contains wetlands and forests, as well as the only McAteean magnolia bogs still remaining in the District. The lower Cretaceous Potomac Group, known as one of the few dinosaur-bearing rock units on the east coast of North America, crops out within Oxon Run. One of the most prevalent fossil-bearing resources are the siderite, or “bog iron” sandstone slabs that sometimes preserve the footprints or trackways of various vertebrates, including dinosaurs. Such trackways have been reported from Potomac Group outcrops throughout the Atlantic Coastal Plain of Maryland and Virginia. In 2019, National Capital Parks-East took possession of such a track, referred to a dinosaur, collected by paleontologist Dr. Peter Kranz. This report was compiled after a paleontological survey of Oxon Run Parkway and is intended as a supplement to the National Capital Parks East Paleontological Resource Inventory (Nelson et al. 2019). This report contains information on the history of Oxon Run Parkway and its geology, as well as discussion of the fossil track.

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Theoretical Correlations and Lateral Discontinuities in the Quaternary Aminostratigraphic Record of the U.S. Atlantic Coastal Plain

Quaternary Research ◽

10.1016/0033-5894(92)90038-k ◽

1992 ◽

Vol 38 (3) ◽

pp. 275-291 ◽

Cited By ~ 14

Author(s):

J. F. Wehmiller ◽

L. L. York ◽

D. F. Belknap ◽

S. W. Snyder

Keyword(s):

South Carolina ◽

Sea Level ◽

Coastal Plain ◽

Late Quaternary ◽

Atlantic Coastal Plain ◽

Passive Margin ◽

Temperature History ◽

Cape Fear ◽

Atlantic Coastal ◽

The U.S

AbstractAminostratigraphic correlations of emergent Quaternary deposits along the U.S. Atlantic Coastal Plain have employed independent radiometric data, regional temperature history models, and assumptions regarding the nature of the preserved late Quaternary sea-level record on this passive margin. A substantial “aminostratigraphic offset” is required if regional aminozones are rigorously constrained by all available Th/U data. New insights regarding the relation of this offset to subsurface stratigraphy in the Cape Fear region of southeastern North Carolina can explain these conflicts as consequences of the highly incomplete post-Cretaceous depositional record of the region. Southward projection of theoretical aminostratigraphic correlation trends suggests that stage 5 correlative marine units are rarely preserved on the emergent portion of the Coastal Plain between Cape Lookout and central South Carolina and that samples of this age would be most frequently found in this region only as fragmentary (and/or reworked) deposits on the inner shelf or in the subsurface of modern barrier islands. If this hypothesis is correct, then the accuracy of several Th/U coral dates from the South Carolina Coastal Plain must be questioned, along with sea-level, tectonic, and paleoclimatic conclusions derived from these dates.

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Detrital-zircon fission-track ages for the “Hoh Formation”: Implications for late Cenozoic evolution of the Cascadia subduction wedge

Geological Society of America Bulletin ◽

10.1130/b22101.1 ◽

2004 ◽

Vol 116 (1) ◽

pp. 60 ◽

Cited By ~ 62

Author(s):

Richard J. Stewart ◽

Mark T. Brandon

Keyword(s):

Detrital Zircon ◽

Fission Track ◽

Late Cenozoic ◽

Zircon Fission Track ◽

Fission Track Ages ◽

Subduction Wedge

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Resolution of the age structure of the detrital zircon populations of two Lower Cretaceous sandstones from the Weald of England by fission track dating

Geological Magazine ◽

10.1017/s0016756800029162 ◽

1984 ◽

Vol 121 (4) ◽

pp. 269-277 ◽

Cited By ~ 115

Author(s):

A. J. Hurford ◽

F. J. Fitch ◽

A. Clarke

Keyword(s):

Detrital Zircon ◽

Lower Cretaceous ◽

Fission Track ◽

Age Distribution ◽

The Other ◽

Fission Track Dating ◽

Zircon Age ◽

Zircon Fission Track ◽

Geological Implications ◽

Fission Track Ages

AbstractModes in the frequency of distribution of fission track ages obtained from detrital zircon grains may prove characteristic of individual sandstone bodies, supporting the identification of the sources from which a particular flow of sedimentary detritus was derived and thus allowing new inferences to be made concerning palaeogeography. A computer program has been written and used to identify modes in the zircon fission track age distribution within two Lower Cretaceous sandstone samples from the Weald of southern England. Pronounced modes appear in one rock around 119 Ma, 160 Ma, 243 Ma and 309 Ma and in the other around 141 Ma, 175 Ma, 257 to 277 Ma and 394 to 453 Ma. The geological implications of these quite dissimilar zircon age spectra are discussed. It is concluded that they support the palaeogeographical models of Allen (1981) and indicate that the provenance of the first sample, from the Top Ashdown Sandstone member at Dallington in East Sussex, was almost entirely southerly, while that of the second, from the Netherside Sand member at Northchapel in West Sussex, was more varied, but predominantly westerly and northerly.

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