Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/3467
Title: The relationship between watershed geology and beach radioactivity
Authors: University of California at Berkeley
United States. Army. Office of the Chief of Engineers
Byerly, John Robert
Keywords: watershed geology
beach radioactivity
quartz diorite
spectroscopic analysis
Issue Date: Aug-1963
Publisher: United States, Beach Erosion Board
Engineer Research and Development Center (U.S.)
Series/Report no.: Technical memorandum (United States. Beach Erosion Board) ; no. 135.
Description: Technical Memorandum
From the Preface: The recent development of techniques using naturally occurring radioactive minerals in monitoring the movement of littoral drift has raised the question of how directly the contributing watershed geology is related to beach radioactivity. Previous studies utilizing a natural radioactive tracer technique involving the element thorium have found that large variations in radioactive concentrations exist in beach materials, and that such variations are often related in some way to the presence of a quartz diorite pluton in the watershed feeding sediment to the beach. A study has now been carried out in the watershed area northwest of Santa Cruz, California, in an attempt to determine how direct is the relationship between watershed geology and beach radioactivity, and to what degree the quartz diorite is responsible for the observed radiometric anomalies. Radioactivity was determined by gamma ray spectroscopic analysis. A description of this study and its results is presented in this report. It is shown that large variations in the thorium content of the watershed sediments do exist; however no correlation between sediment radioactivity and known geological features and variations is apparent. The study also concludes that the applicability of a naturally occurring radioactive tracer method for a particular area cannot be predetermined by a simple study of geological maps and petrographic descriptions; but preliminary sampling must be conducted to determine a tracer source. As the method and its results appear of interest in the field of beach erosion and shore processes, and particularly in the definition of source areas for beach material, this report is now being published as a Beach Erosion Board Technical Memorandum.
URI: http://hdl.handle.net/11681/3467
Appears in Collections:Technical Memorandum

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