Mapping the floor of Lake Mead (Nevada and Arizona): Preliminary discussion and GIS data release, USGS Open-File Report 03-320

Figure 8. Click in figure for larger image. Sidescan-sonar image showing part of Boulder Basin. The post-impoundment sediment has a low-backscatter signature (in contrast to Gregg Basin), and it is bounded to the south by alluvial fans and to the north by exposures of Cenozoic sedimentary strata. The two sub parallel, linear, moderate backscatter bands that cross the center of the post-impoundment deposit overlie the flanks of the Colorado River. Here the post-impoundment sediment is approximately 15 m thick, and preservation of the channel flanks on the present lake floor is probably due to compaction of the post-impoundment sediment after deposition. The figure location is shown in Figure 3.

Title Page / Contents / Discussion / GIS Data / Contacts