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Seismic Reflection Surveys
Drayton Island

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Open File Report:
Seismic Reflection
Surveys
  Abstract
  Introduction
  Karst Formation
  Methods
  Regional Geology
  Orange Lake
  Kingsley Lake
  Lowry & Magnolia Lakes
  Drayton Island You are at Seismic Reflection Surveys - Drayton Island
  Conclusions
  References
Contact:
Jim Flocks
 
 
Location of seismic profiles collected from the vicinity of Drayton Island in Lake George. Click on the number in red to view Figure 33.
Figure 33 In February, 1994, reconnaissance profiles were run from the vicinity of Drayton Island that is situated in the confluence of the St. Johns River and Lake George in Putnam county (Fig. 3) to Palatka. These surveys were conducted to test data acquisition in the St. Johns River for future more detailed work.

An example of this data from the northern portion of Lake George (Fig. 10) is shown in Figure 33. This is an example of a deep buried subsidence sinkhole. Reflections are resolvable at depths of 44 milliseconds (37 meters, 120 feet) at this site and even deeper in others. The surveys provided excellent detail of cross bedding in the river channel and identified other buried sinkholes along the channel. Resolution was poor in areas where bottom conditions caused multiples and post processing did little to enhance the data. Further work is being done to assess the data for previously mapped faults, structure and morphology of the Croaker Hole near Welaka and correlation to available borehole geophysical data.

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