Identifying the physical processes that control the stratigraphic record

May 07, 2013

The stratigraphic record, the sequential layers of sediment that geologists use to reconstruct the history of a landscape, has been described as "more gaps than record." The record, laid down over time as sediment settles out from flowing water, does not grow consistently. Pauses in sediment deposition can leave gaps, and periods of heightened erosion can wipe sections out.

Though attempts have been made to identify the processes that control the completeness of the stratigraphic record, early analyses relied on parameters (such as the long-term rate) that are not first-order physical landscape processes.

Building on that earlier work, Straub and Esposito used a series of laboratory experiments to identify the physical processes that are relevant to controlling the accumulating stratigraphic record, and to determine the relationships between these processes.

The authors built a series of artificial river deltas, each with varying water flow and sedimentation rates, and used time-lapse photography and topographic measurements to track how the stratigraphic record developed.

They find that the stratigraphic record is most complete when the rate is high, when the water flow rate relative to the rate is low, and when the river channel migrates slowly across the whole delta region.

Explore further: Mexico's Volcano of Fire blows huge ash cloud

More information: Influence of water and sediment supply on the stratigraphic record of alluvial fans and deltas: Process controls on stratigraphic completeness, Journal of Geophysical Research-Earth Surface, doi:10.1002/jgrf.20061, 2013

add to favorites email to friend print save as pdf

Related Stories

Three Gorges Dam shrinking Yangtze delta

May 21, 2007

Chinese scientists have determined how China's Three Gorges Dam -- the world's largest dam -- affects downstream sediment delivery in the Yangtze River.

Recommended for you

Biology trumps chemistry in open ocean

3 hours ago

Single-cell phytoplankton in the ocean are responsible for roughly half of global oxygen production, despite vast tracts of the open ocean that are devoid of life-sustaining nutrients. While phytoplankton's ...

Underwater robot sheds new light on Antarctic sea ice

8 hours ago

The first detailed, high-resolution 3-D maps of Antarctic sea ice have been developed using an underwater robot. Scientists from the UK, USA and Australia say the new technology provides accurate ice thickness ...

Damage caused by geothermal probes is rare

10 hours ago

Soil settlements or upheavals and resulting cracks in monuments, floodings, or dried-up wells: Reports about damage caused by geothermal probes have made the population feel insecure. In fact, the probability ...

Extreme shrimp may hold clues to alien life

12 hours ago

(Phys.org) —At one of the world's deepest undersea hydrothermal vents, tiny shrimp are piled on top of each other, layer upon layer, crawling on rock chimneys that spew hot water. Bacteria, inside the shrimps' ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.