Sedimentdicken

Sedimentdicken, or sediment thickness, refers to the vertical distance between the basement rock and the Earth's surface that is occupied by deposited sediments in a given area. It is commonly expressed in meters or kilometers and is mapped as isopach lines to show regions of equal thickness. The quantity reflects the history of subsidence, sediment supply, and erosion that have acted on a basin or shelf over geological time.

Measuring sediment thickness relies on integrating stratigraphic data and geophysical surveys. Seismic reflection methods are the primary tool, revealing the depth to the top of the basement or the base of sediments. Boreholes provide ground-truth measurements at specific points. Gravity and magnetic surveys, along with electromagnetics such as magnetotellurics, help infer thick sediment sections where seismic data are sparse. Modern work often combines these data into regional models and generates isopach maps or 3D sediment thickness volumes.

Thickness varies widely: continental shelves and passive margins may host tens to a few hundred meters of sediments, while intracontinental basins can exceed a kilometer; deep offshore basins and foreland basins can reach several kilometers. The distribution is controlled by tectonics, subsidence rate, sediment supply, sea level changes, and erosion.

Sediment thickness is a key parameter in hydrocarbon exploration, groundwater and aquifer assessment, geotechnical engineering, and basin modeling of sedimentary processes and climate history. The concept is widely used in geology, geophysics, and planetary science.

Challenges include data gaps, unconformities, thrust tectonics, burial diagenesis, and age dating uncertainties, which complicate thickness estimation. Harmonization of datums and reference levels is important for comparing results across regions.