geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Relationship of D18O and D13C of foraminiferal tests to bottom-water salinity in an Atlantic coastal lagoon, Delaware, USA


, : Relationship of D18O and D13C of foraminiferal tests to bottom-water salinity in an Atlantic coastal lagoon, Delaware, USA. Abstracts with Programs - Geological Society of America 38(7): 227

We examined a spatial array of sites in Rehoboth Bay, a lagoonal estuary along the Atlantic Coast of Delaware (USA), to evaluate the possible use of stable isotopes of benthic foraminiferal tests to track the relative proportions of river versus marine water input. Samples were taken at 29 sites in Rehoboth Bay in August 2005. The bay is shallow (mostly less than 2 m) and microtidal. During the summer, a number of small tidal rivers provide an input of lower salinity, higher temperature water; in contrast, marine input is through a single inlet, providing lower temperature, higher salinity waters. Given these temperature and salinity relationships, we would expect that foraminiferal tests from sites closer to fresh water sources should have lower d18O values than samples from sites located farther away. To test the potential of estuarine foraminifera in the Rehoboth Bay for paleoenvironmental reconstruction, we have selected living and dead tests of two calcareous foraminiferal species: Ammonia beccarii and Elphidium poeyanum. Both species yield consistent results in that d18O values are indeed lower at the sites closer to the river and increase with distance from it. Specifically, highest statistical significance between test geochemistry and modern conditions is observed between d18O values of living E. poeyanum and salinity (r2=0.72). For both d13C and d18O the dead E. poeyanum show better correlation with temperature (d18O, r2= 0.54; d13C, r2=0.19) than the living ones. For A. beccarii, d18O values of living individuals also show better correlation with salinity (r2=0.49) and temperature (r2=0.36) than dead ones (r2=0.31; r2=0.30); however the d13C from the dead individuals show better correlation with salinity (r2= 0.17) and temperature (r2=0.24) than the living ones. The d13C values show similar relationship to d18O values, which is consistent with modern conditions as river water is generally enriched in 12C with respect to open marine water. These cores top results suggest that stable isotopes of tests of these foraminiferal species reflect mixing of marine and fresh waters in this lagoon, and that a down core study to evaluate salinity history in this estuary is feasible.

US$29.90


Other references

Padilla, L.E.; Winchell, M.F.; Jackson, S.H., 2015: Evaluation of AGRO-2014 for Predicting Hydrophobic Organic Chemical Concentrations in Ponds. Highly hydrophobic organic chemicals (HOCs), like pyrethroids, adsorb strongly to eroded soil and suspended sediment. Therefore, total suspended solids (TSS) concentration in the water column of receiving waters is important for determining the pr...

Pedry John Joseph, 1957: Cottonwood Creek field, Washakie County, Wyoming, carbonate stratigraphic trap. Bulletin of the American Association of Petroleum Geologists 41(5): 823-838

Smirnov, SV., 1991: Paedomorphosis as a mechanizm of evolutionary transformation. Unknown

Suttle, J.C.; Hultstrand, J., 1986: Growth retarding effects of the herbicide difenzoquat. Growth-regulating properties of difenzoquat were investigated in seedlings and cell suspension cultures of sunflower. Application of <more or =>10 micro g difenzoquat to the apex of seedlings resulted in a transient inhibition of internode e...

Auer, L.; Trummer, G., 1980: Pial arteriolar reaction to intravenous administration of bencyclane in the cat. In a series of 29 experiments in cats, the vasodilatory effect of Bencyclane on pial arterioles was investigated by means of the cranial window technique, using an image-splitting eyepiece, a photometric method or simple microscopic observation. I...

Wijkstrom H.; Tribukait B., 1990: Dna flow cytometry in predicting response to radical radiotherapy of bladder cancer. Using flow cytometry tumors can be classified according to their deoxyribonucleic acid content as diploid or aneuploid with 1 or several cell lines and to the ploidy level of the aneuploid cell lines, as well as to the proportion of proliferating...

David, J.C., 1975: Tryptophan decarboxylation: a quantitatively significant route of tryptophan metabolism. Febs Letters 55(1): 81-83

Demichelis, S.; Manino, A., 1998: Electrophoretic detection of parasitism by Dryinidae in Typhlocybinae leafhoppers (Homoptera: Auchenorrhyncha). Nine species of the subfamily Typhlocybinae were collected from Corylus avellana, potatoes and grapes in Italy. Seven species were parasitized by Dryinidae, among which Alebra coryli and Edwardsiana staminata were recognized for the first time as...

Landewé, R.; van der Heijde, D., 2002: Follow up studies in rheumatoid arthritis. Annals of the Rheumatic Diseases 61(6): 479-481

Way, B.B., 1986: The use of restraint and seclusion in New York State psychiatric centers. International Journal of Law and Psychiatry 8(4): 383-393