Cyclothem

{
  "id": "MLC-T-OAG-004282",
  "term": "Cyclothem",
  "field": "Oil and gas",
  "definition": "A specific, repeating sequence of sedimentary rock layers that records a single cycle of marine transgression and regression. A classic Pennsylvanian cyclothem consists of a series of nonmarine deposits, such as sandstone and shale, overlain by a coal bed, which is in turn overlain by marine shales and limestones. These cycles are interpreted as the result of fluctuating sea levels caused by glacial-eustatic changes.",
  "subject": "Reservoir Characterization",
  "url": "https://mlchart.com/terminology/oil-and-gas/cyclothem/"
}