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Title: Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana

Abstract

Historical, seismic and vibracore data were used to determine the geologic framework of sand deposits along the predominantly muddy coastline of eastern Barataria Bight, Louisiana. Three inlet types with distinct sand body geometries and morphologies were identified and are found 1) at flanking barrier island systems spread laterally across the front of interdistributary bays; 2) in old distributary channels; 3) at overwash breaches; or 4) combination of these. Barataria Bight, a sheltered barrier island shoreline embayment with limited sand supply, minimal tidal range (36 cm) and low wave energies (30 cm) can be used to show examples of each inlet type. Barataria Pass and Quatre Bayou Pass are inlets located in old distributary channels. However, Barataria Pass has also been affected by construction between barrier islands. Pass Ronquille is located where the coastline has transgressed a low area in the delta plain. This breach is situated in a hydraulically efficient avenue between the Gulf and Bay Long behind it. Pass Abel is a combination of a low-profile barrier breach and the reoccupation of an old distributary channel. Shelf and shoreline sands are reworked from abandoned deltaic distributaries and headlands. Inner shelf sands are concentrated in thick (10 m) shore-normal relictmore » distributary channels with fine grained cross-bedded and ripple laminated sand overlain by burrowed shelf muds. Shoreface sand deposits occur as 2-3 m thick, fine-grained, coarsening upward and burrowed ebb-tidal delta sequences and shore-parallel relict tidal inlet channels filled through lateral accretion.« less

Authors:
;
Publication Date:
Research Org.:
Louisiana State Univ., Baton Rouge (USA)
OSTI Identifier:
6456649
Report Number(s):
CONF-8510489-
Journal ID: CODEN: GAAPB
Resource Type:
Conference
Resource Relation:
Journal Name: Geol. Soc. Am., Abstr. Programs; (United States); Journal Volume: 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; CONTINENTAL SHELF; SEISMIC SURVEYS; STRATIGRAPHY; LOUISIANA; COASTAL REGIONS; DEPOSITION; GEOLOGIC HISTORY; LITHOLOGY; SANDSTONES; SEDIMENTS; CONTINENTAL MARGIN; FEDERAL REGION VI; GEOLOGY; GEOPHYSICAL SURVEYS; NORTH AMERICA; ROCKS; SEDIMENTARY ROCKS; SURVEYS; USA 580100* -- Geology & Hydrology-- (-1989)

Citation Formats

Moslow, T.F., and Levin, D.R. Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana. United States: N. p., 1985. Web.
Moslow, T.F., & Levin, D.R. Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana. United States.
Moslow, T.F., and Levin, D.R. 1985. "Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana". United States. doi:.
@article{osti_6456649,
title = {Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana},
author = {Moslow, T.F. and Levin, D.R.},
abstractNote = {Historical, seismic and vibracore data were used to determine the geologic framework of sand deposits along the predominantly muddy coastline of eastern Barataria Bight, Louisiana. Three inlet types with distinct sand body geometries and morphologies were identified and are found 1) at flanking barrier island systems spread laterally across the front of interdistributary bays; 2) in old distributary channels; 3) at overwash breaches; or 4) combination of these. Barataria Bight, a sheltered barrier island shoreline embayment with limited sand supply, minimal tidal range (36 cm) and low wave energies (30 cm) can be used to show examples of each inlet type. Barataria Pass and Quatre Bayou Pass are inlets located in old distributary channels. However, Barataria Pass has also been affected by construction between barrier islands. Pass Ronquille is located where the coastline has transgressed a low area in the delta plain. This breach is situated in a hydraulically efficient avenue between the Gulf and Bay Long behind it. Pass Abel is a combination of a low-profile barrier breach and the reoccupation of an old distributary channel. Shelf and shoreline sands are reworked from abandoned deltaic distributaries and headlands. Inner shelf sands are concentrated in thick (10 m) shore-normal relict distributary channels with fine grained cross-bedded and ripple laminated sand overlain by burrowed shelf muds. Shoreface sand deposits occur as 2-3 m thick, fine-grained, coarsening upward and burrowed ebb-tidal delta sequences and shore-parallel relict tidal inlet channels filled through lateral accretion.},
doi = {},
journal = {Geol. Soc. Am., Abstr. Programs; (United States)},
number = ,
volume = 17,
place = {United States},
year = 1985,
month = 1
}

Conference:
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  • The influence of tidal inlets on longshore sediment transport in low energy systems can be characterized by the inlet morphology. The stability of the inlet morphology is dependent on the inlet's hydrodynamic parameters and the intensity and frequency of meteorological events impacting the inlet. The tidal inlets of southwest Florida are indicative of low-energy systems and are used in this paper to illustrate the sand-by-pass mechanisms which prevail in this type of energy regime. The inlet by-pass mechanisms are correlated with the morphology to qualitatively derive a tool for inlet comparisons and field data collection program design. Wiggins Pass inletmore » is utilized as an example of the morphological classification and sand-by-pass mechanisms correlation. Intensive field monitoring of the inlet's hydrodynamic parameters and sand budget was undertaken in November 1982 in the design phase of a navigational dredging project which was constructed in February 1984. The survey data are utilized to evaluate the mechanism of sand transport across the inlet as related to inlet morphology and shoreline changes. Photogrammetric comparisons to five other inlets in southwest Florida are also presented. The applicability of the MC-SBMC method of analyzing sand-transport influence by these low-energy system inlets is discussed.« less
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  • The northwestern peninsular Florida coast is microtidal, low wave energy. Topographic complexity is due to karstified Tertiary limestone, actively discharging freshwater springs, and lack of pre-Holocene sediment veneer. This complexity helps control local sedimentary processes. In the southern part of the field area a near continuous, thin Pleistocene quartz sand allows a marsh-fronting berm and simpler shoreline morphology. To the north, freshwater springs have formed shallow estuarine embayments containing linear oyster bioherms, nucleated upon local bedrock highs. These molluscan reefs enclose interbiothermal basins, segmenting the embayments. Between the embayments are archipelagoes of marsh islands and tidal creeks. Their complex topographymore » was formed from selective dissolution along rectilinear fractures, creating linear lows which when drowned by rising sea level formed the largest tidal creeks. Marsh islands formed on intervening low-relief knobs. These commonly support oases of less salt tolerant shrubs and trees, surrounded by Juncus roemerianus marsh. Landward to seaward changes in rock/sedimentation relationships suggest an evolutionary pattern during sea-level rise. Upland forests become hammocks surrounded by marsh. Hammocks become islands surrounded by tidal creeks. Submerged hammocks finally become highs supporting oyster reefs. Preservation potential during the present slow transgression is low, due primarily to the low relief.« less
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