Uranium anomalies in organic lake sediments might be false if not accompanied by high radium

  • Uranium is concentrated by organic matter such as some of the sediments (gyttja?) found in lakes and streams in the Canadian Shield. Radium is less strongly concentrated.

  • All of the radium in the earth comes from radioactive decay of uranium. These two elements have very different chemical behaviour and can get separated during geological processes. Once radium is separated from uranium it takes a million years to grow back into equilibrium. Therefore, in young sediments like gyttja, which are at most a few thousand years old, uranium and radium are not in equilibrium. If these two elements have both come from the same nearby orebody, they arrived in the sediment by separate processes.

  • If anomalous concentrations of uranium in sediment are due to nearby enrichments of uranium in rock, then radium values in the sediment would also be high. Absence of high radium values in these uranium anomalies suggests that chemical activity in the sediment is responsible for the uranium enrichment -- a false anomaly.

  • All suspicious uranium anomalies in organic sediment should be analysed for radium as well. In fact, radium analyses, as opposed to uranium, might be a better first choice in geochemical prospecting for uranium.

  • Most of the radon in lake water comes from radium in the lake sediment. Analysis of lake-bottom waters for radon will give a good indication of the radium content of the sediment, and in some cases will be more readily available. Link.

  • Radium and radon are readily determined by our portable radon detectors.

  • We measure: radon - radium - thoron - radon daughters - alpha radiation.
  • The Lucas cell is recognized as the most sensitive and reliable method for these elements.
  • Intrinsically safe functions.
  • Sensitive to geochemical trace levels necessary for radon in lake water and for radon-thoron isotope ratios.
  • immune to beta and gamma radiation.
  • one monitor works with a number of (less expensive) detectors.
  • Our instruments are used around the world in exploration for uranium, oil & gas, groundwater and hydrothermal, and in environmental protection, health physics, earthquake prediction, and evaluation of hydrocarbon and NAPL contamination etc.
  • Same instruments used for radon and radium in soil, sediment, plant parts, rocks, water, soil gas, air, snow, food, and for radon and thoron daughters in air.
  • Winter and summer, from the Sahara Desert to the Canadian Shield, our instruments have faced up to severe field conditions.
  • In the radon business since 1968, our instruments are updated regularly with the most recent major re-design in 2015. Modern, low-power, field-rugged electronics. Some earlier versions still working after 40 years.
  • Continuous real-time monitoring and data recording.
  • RS232 port/pc software.
  • User programmable measurement intervals, sample and count periods and alarm level settings.
  • Can work in a tent without electricity or be carried from point to point in the field.
  • 50 readings per day. Results available immediately.
  • Portable. Rechargeable battery pack good for a long day in the field and recharges in a few hours.
  • Can be operated by junior personnel if carefully supervised.
  • EPA and CE Mark compliant.
  • Click here (www.finderschoice.com/rn) for more details of our radon instruments, and for other instruments, components and accessories we provide.
  • Technical specification sheets and pictures of our instruments provided on request.
  • Multilingual consulting and training (if required).
For instruments contact

Robert H. Morse, Ph.D., P.Eng.
March 21, 2010
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