scholarly journals Modern saltmarsh diatom distributions of the Outer Banks, North Carolina, and the development of a transfer function for high resolution reconstructions of sea level

2006 ◽  
Vol 69 (3-4) ◽  
pp. 381-394 ◽  
Author(s):  
Benjamin P. Horton ◽  
Reide Corbett ◽  
Stephen J. Culver ◽  
Robin J. Edwards ◽  
Caroline Hillier
2011 ◽  
Vol 76 (3) ◽  
pp. 319-334 ◽  
Author(s):  
Candace Grand Pre ◽  
Stephen J. Culver ◽  
David J. Mallinson ◽  
Kathleen M. Farrell ◽  
D. Reide Corbett ◽  
...  

AbstractForaminiferal analyses of 404 contiguous samples, supported by diatom, lithologic, geochronologic and seismic data, reveal both rapid and gradual Holocene paleoenvironmental changes in an 8.21-m vibracore taken from southern Pamlico Sound, North Carolina. Data record initial flooding of a latest Pleistocene river drainage and the formation of an estuary 9000 yr ago. Estuarine conditions were punctuated by two intervals of marine influence from approximately 4100 to 3700 and 1150 to 500 cal yr BP. Foraminiferal assemblages in the muddy sand facies that accumulated during these intervals contain many well-preserved benthic foraminiferal species, which occur today in open marine settings as deep as the mid shelf, and significant numbers of well-preserved planktonic foraminifera, some typical of Gulf Stream waters. We postulate that these marine-influenced units resulted from temporary destruction of the southern Outer Banks barrier islands by hurricanes. The second increase in marine influence is coeval with increased rate of sea-level rise and a peak in Atlantic tropical cyclone activity during the Medieval Climate Anomaly. This high-resolution analysis demonstrates the range of environmental variability and the rapidity of coastal change that can result from the interplay of changing climate, sea level and geomorphology in an estuarine setting.


2020 ◽  
Author(s):  
Fatin Izzati Minhat ◽  
◽  
Nazihah Azmi ◽  
Nazihah Azmi ◽  
Nur Hidayah Roseli ◽  
...  

2008 ◽  
Vol 69 (1) ◽  
pp. 97-109 ◽  
Author(s):  
David Mallinson ◽  
Kevin Burdette ◽  
Shannon Mahan ◽  
George Brook

Luminescence ages from a variety of coastal features on the North Carolina Coastal Plain provide age control for shoreline formation and relative sea-level position during the late Pleistocene. A series of paleoshoreline ridges, dating to Marine Isotope Stage (MIS) 5a and MIS 3 have been defined. The Kitty Hawk beach ridges, on the modern Outer Banks, yield ages of 3 to 2 ka. Oxygen-isotope data are used to place these deposits in the context of global climate and sea-level change. The occurrence of MIS 5a and MIS 3 shorelines suggests that glacio-isostatic adjustment (GIA) of the study area is large (ca. 22 to 26 m), as suggested and modeled by other workers, and/or MIS 3 sea level was briefly higher than suggested by some coral reef studies. Correcting the shoreline elevations for GIA brings their elevation in line with other sea-level indicators. The age of the Kitty Hawk beach ridges places the Holocene shoreline well west of its present location at ca. 3 to 2 ka. The age of shoreline progradation is consistent with the ages of other beach ridge complexes in the southeast USA, suggesting some regionally contemporaneous forcing mechanism.


Author(s):  
Laura J. Moore ◽  
Jeffrey H. List ◽  
S. Jeffress Williams ◽  
David Stolper

Author(s):  
N. Bonnet ◽  
M. Troyon ◽  
P. Gallion

Two main problems in high resolution electron microscopy are first, the existence of gaps in the transfer function, and then the difficulty to find complex amplitude of the diffracted wawe from registered intensity. The solution of this second problem is in most cases only intended by the realization of several micrographs in different conditions (defocusing distance, illuminating angle, complementary objective apertures…) which can lead to severe problems of contamination or radiation damage for certain specimens.Fraunhofer holography can in principle solve both problems stated above (1,2). The microscope objective is strongly defocused (far-field region) so that the two diffracted beams do not interfere. The ideal transfer function after reconstruction is then unity and the twin image do not overlap on the reconstructed one.We show some applications of the method and results of preliminary tests.Possible application to the study of cavitiesSmall voids (or gas-filled bubbles) created by irradiation in crystalline materials can be observed near the Scherzer focus, but it is then difficult to extract other informations than the approximated size.


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