Sand Volume Estimates

Volumetric estimations for Fenwick, Weaver, & Isle of Wight shoals used vibracore data collected in 1992 & 1997, volumes were calculated in 2000 (Conkwright, Williams and Christiansen, 2000). Borrow Area 2 has been virtually exhausted by dredging. Between 1988-1992, ~2.9 million m^3 was dredged from Borrow Area 2, ~4.2 million m^3 dredged from Borrow Area 3, and ~3.2 million m^3 dredged from Borrow Area 9 (Wells, 1994). Revised volumentric estimations for Shoals B, C, D, Little Gull Bank & Great Gull Bank (1996) "In the 1993 sand resources study (Conkwright and Gast, 1994b) the seismically defined ravinement surface was used as the lower structural boundary for volume calculations. However, the purpose of the current study is to estimate only the volume of sand with measured physical parameters. Therefore, the lower boundary for volumetric calculations was determined primarily by the grain size parameters of vibracore samples. The lower boundary surface was set at the depth where the sampled sand became too fine or too poorly sorted for use as beach fill. In those cases where the entire length of core contained usable sand, the boundary surface was set at the depth of maximum vibracore penetration. Because vibracore penetrations on Little and Great Gull Banks were generally within a meter of the ravinement surface, that surface was used as the lower boundary for those shoals, unless vibracore samples indicated otherwise." (Conkwright and Williams, 1996). REFS: Conkwright, R.D. and R.A.Gast. 1994a. Potential Offshore Sand Resources in Southern Maryland Shoal Fields. Coastal and Estuarine Geology File Report #95-4 Conkwright, R.D. and R.A.Gast. 1994b. Potential Offshore Sand Resources in Central Maryland Shoal Fields. Coastal and Estuarine Geology File Report #95-9 Conkwright, R.D. and C.P. Williams. 1996. Offshore Sand Resources in Central Maryland Shoal Fields. Coastal and Estuarine Geology File Report #96-3 Conkwright, R.D., Williams, C.P., and L.B. Christiansen. 2000. Offshore Sand Resources in Northern Maryland Shoal Fields. Coastal and Estuarine Geology File Report No. 00-2 Wells, D.V. 1994. Non-Energy Resources and Shallow Geological Framework of the Inner Continental Margin Off Ocean City, Maryland. Coastal and Estuarine Geology Open File Report #16USACE. 2008. Atlantic Coast of Maryland Shoreline Protection Project Final supplemental Environmental Impact Statement General Reevaluation Study: Borrow Sources for 2010-2044

Funding to compile these datasets provided by BOEM under cooperative agreement number: M14AC00007. Data processing and compilation was executed by Maryland Geological Survey.

本数据集针对芬威克（Fenwick）、韦弗（Weaver）及怀特岛浅滩（Isle of Wight shoals）开展体积估算，所用数据为1992年与1997年采集的振动岩心（vibracore）取样数据，体积计算工作于2000年完成（Conkwright、Williams与Christiansen，2000）。

2号采砂区（Borrow Area 2）已因长期疏浚作业基本枯竭。1988年至1992年间，2号采砂区疏浚采砂量约290万立方米，3号采砂区约420万立方米，9号采砂区约320万立方米（Wells，1994）。

针对B浅滩、C浅滩、D浅滩、小海鸥滩（Little Gull Bank）与大海鸥滩（Great Gull Bank）的1996年修订体积估算结果如下：“1993年砂资源研究中（Conkwright与Gast，1994b），以地震识别的侵蚀面（ravinement surface）作为体积计算的下部结构边界。然而本研究仅估算具备实测物理参数的砂体体积，因此体积计算的下部边界主要依据振动岩心样品的粒度参数确定。当下边界面设置在采样砂体过细或分选过差、无法作为海滩填筑用料的深度处。若岩心全段均含可用砂体，则将下部边界面设置为振动岩心最大贯入深度。由于小海鸥滩与大海鸥滩的振动岩心贯入深度通常距侵蚀面不足1米，因此除非振动岩心样品另有指示，否则该侵蚀面将作为这两处浅滩的下部计算边界。”（Conkwright与Williams，1996）

参考文献：
1. Conkwright, R.D. 及 R.A. Gast. 1994a. 《马里兰州南部浅滩区潜在近海砂资源》. 海岸与河口地质文件报告 #95-4
2. Conkwright, R.D. 及 R.A. Gast. 1994b. 《马里兰州中部浅滩区潜在近海砂资源》. 海岸与河口地质文件报告 #95-9
3. Conkwright, R.D. 及 C.P. Williams. 1996. 《马里兰州中部浅滩区近海砂资源》. 海岸与河口地质文件报告 #96-3
4. Conkwright, R.D., Williams, C.P. 及 L.B. Christiansen. 2000. 《马里兰州北部浅滩区近海砂资源》. 海岸与河口地质文件报告 第00-2号
5. Wells, D.V. 1994. 《马里兰州大洋城近海陆架浅水区非能源资源与浅层地质框架》. 海岸与河口地质公开文件报告 #16
6. 美国陆军工程兵团（United States Army Corps of Engineers, USACE）. 2008. 《马里兰州大西洋海岸岸线防护项目最终补充环境影响评价 通用重评估研究：2010-2044年采砂源》

本数据集的汇编资助由美国海洋能源管理局（Bureau of Ocean Energy Management, BOEM）通过合作协议编号M14AC00007提供，数据处理与汇编工作由马里兰州地质调查局（Maryland Geological Survey）执行。