SAND RESOURCES OF SOUTHEASTERN LAKE MICHIGAN 



Edward P. Meishicrger, S. Jeffress Williams ^ and Dennis A. Prins 



I . INTRODUCTION 



The construction, improvement, and periodic maintenance of beaches 

 and dimes by placement of suitable sand along the shoreline is an im- 

 portant means of counteracting coastal erosion and of enhancing coastal 

 recreational facilities (U.S. Army, Corps of Engineers, Coastal Engineer- 

 ing Research Center, 1977).^ In recent years, it has become increasingly 

 difficult to obtain large volumes of suitable sand from lagoons and in- 

 land sources because of diminishing resources as well as economic and 

 ecological factors. Accordingly, the Coastal Engineering Research Center 

 (CERC) initiated an Inner Continental Shelf Sediment and Structure (ICONS) 

 study to locate offshore sand resources suitable for beach fill. This 

 report deals with the location and physical characteristics of offshore 

 sand resources in parts of eastern and southern Lake Michigan. 



A zone adjacent to the shore about 4.8 to 9.7 kilometers (3 to 6 

 miles) wide, extending from Manistee, Michigan, to Burns Harbor, Indiana, 

 constitutes the study area (Fig. 1). Survey coverage of the area is shown 

 in Figures 2 to 7. Collected data consist of 915 kilometers (569 miles) 

 of reflection profiles and 93 cores ranging from 0.6 to 6.1 meters (2 to 

 20 feet) in length. In addition, side-scan sonar and low-energy seismic 

 reflection records of each core site were obtained during coring opera- 

 tions. These data were supplemented by pertinent scientific and techni- 

 cal literature and National Ocean Survey (NOS) hydrographic data. 



This report is primarily the result of a reconnaissance effort; seis- 

 mic line spacing and core density are not suitably detailed for reliable 

 delineation of offshore borrow sites. Consequently, denser data coverage 

 and more detailed study of potential borrow sites are needed before final 

 site selection is made for project design and construction. 



II. PROCEDURES 

 1. Seismic Survey . 



Seismic reflection profiles were run along the coast of the study 

 area following a zigzag pattern in an onshore-offshore direction (Figs. 

 2 to 7). Two seismic reflection profiling systems were operated simul- 

 taneously during the survey (a high-energy "boomer" system of 0.4 to 14 



^U.S. ARMY, CORPS OF ENGINEERS, COASTAL ENGINEERING RESEARCH CENTER, 

 Shore Protection Manual, 3d ed. , Vols. I, II, and III, Stock No. 

 008-022-00113-1, U.S. Government Printing Office, Washington, D.C., 

 1977, 1,262 pp. 



