Thorium

{
  "id": "MLC-T-OAG-003818",
  "term": "Thorium",
  "field": "Oil and gas",
  "definition": "A naturally occurring radioactive element whose concentration in rock is measured by spectral gamma ray logging tools. Along with potassium and uranium, it is one of the three primary sources of natural gamma radiation detected in a wellbore. The abundance of thorium, measured in parts per million (ppm), is used as an indicator of clay and shale content, as it is primarily associated with heavy minerals found in shales.",
  "subject": "Formation Evaluation",
  "url": "https://mlchart.com/terminology/oil-and-gas/thorium/"
}