What are Geopetal Infills?

What are Geopetal Infills?

Geopetal structures are commonly found in cavity fills within limestones, where the lower part of the cavity has been filled with sediment and the upper part filled later with cement.

What are primary sedimentary structures?

Primary sedimentary structures: occur in clastic sediments and produced by the same processes (currents, etc.) that caused deposition. Includes plane bedding and cross-bedding.

How are flame structures formed?

A flame structure is a type of soft-sediment deformation that forms in unconsolidated sediments. The weight of an overlying bed forces an underlying bed to push up through the overlying bed, generally when both strata are saturated with water. The resulting pattern (in cross section) may resemble flames.

What are primary and secondary sedimentary structures?

1. Primary sedimentary structures are generated at the time or shortly after deposition by physical processes. 2. Secondary sedimentary structures are formed after deposition mainly by chemical processes.

What is secondary sedimentary structure?

secondary sedimentary structure A structure formed by the precipitation of minerals in the pores of a sedimentary rock during or following its consolidation, or by chemical replacement of some of its constituents.

Where do flame structures occur?

Flame structures form as the upper part sinks into the underlying sediment, often referred to as ‘loading’. This loading commonly occurs in localized pods and then the sediment in between gets squeezed up a bit.

What are flute casts?

Flute casts or sole marks are the preserved remnants of water flowing over and eroding sediments. To be preserved, softer sediment must wash over the surface and fill in the structures eroded by the water. The water scours a small depression that is steep on the upstream side and a lower angle on the downstream side.

How are sedimentary structures formed?

Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition. Sediments and sedimentary rocks are characterized by bedding, which occurs when layers of sediment, with different particle sizes are deposited on top of each other.

What is convolute lamination?

Convolute lamination is a common fold structure within turbidite beds, attributed to the deformation of sediment during or soon after deposition of the host bed. Despite the prevalence of this feature, the formational processes are still not well understood.

What do mud cracks indicate?

3. What do mud cracks tell about the environment of deposition of a sedimentary rock? They indicate an environment in which sediment got wet and then dried out. Such an environment could be a flood plain, or tidal flat.

Where do turbidites form?

Turbidites are deposited from slurries of sediment and water in any standing body of water (lakes, oceans). They can occur in any layer of a water body (near surface, benthic) as long as there is an oversteepened slope. The fluid involved is water, which mixes with sediment.

How do flutes form?

Flute casts form by erosive scour. The most common geologic phenomena that produce flute casts are turbidity currents (underwater sediment slides). Sedimentary rocks representing deposition by ancient turbidity currents are called turbidites. Many turbidite successions have well preserved flute casts.