Karakteristieken - Layering

Page / - last modified by Roelof Zwaan on 2021/09/30 15:20

Layering

last modified by Roelof Zwaan

on 2021/09/30 15:20

Table of Contents

A layer is an horizontal organization of material, especially one of several parallel layers arranged one on top of another. A bed or layer of sedimentary rock is visually distinguishable from adjacent beds or layers. Layers describe a large amount of rock which has one indistinguishable type. For example sandstone. This sandstone still can have clay lamina present within its layer. Further on this page some examples of layers can be found.

Layer Transitions

The layering within a cycle of soil/rocks can have different boundaries on its top and bottom. This layering transitions are defined as below.

Class	Type	Description
L01	Derivative	The transition is not based on a change in the sample, but on a change in behaviour of drilling.
L02	Predetermined	The transition is not based on a perceived change, but artificially determined and coincides with the transition of a sampled interval or the transition of a described interval.
L03	Derived probe	The transition is derived from a probe within a range of 5 m from the borehole.
L04	Observed randomly	Observed size transition area in sample: >100mm.
L05	Observed diffuse	Observed size transition area in sample: ≥30 mm - <100 mm.
L06	Observed gradually	Observed size transition area in sample: ≥3 mm - <30 mm.
L07	Observed sharp	Observed size transition area in sample: <3 mm.

Layer thickness

Layer thickness is a factor that determines the thickness of the primary layers and is categorised in the following categories.

Term	Thickness (mm)
Thin laminated	<6
Thickly laminated	6 - 20
Layered very thin	20 - 60
Thin layered	60 - 200
Mm layered	200 - 600
Cm layered	600 - 2000
Dm layered	> 2000

Examples

Clay layers

For explanation see clay.

Detritus layers

For explanation see detritus.

Gravel layers

For explanation see gravel.

Gyttja layers

For explanation see gyttja.

Heterogeneous

Heterogeneous layers are many different sediments which are layered on top of each other. Most of the time there can be a sequence spotted within this layering.

Homogeneous

Homogeneous layers are layers on top of each other with the same sediments or material. The layers can differ in deposition environment.

Loam layers

For explanation see loam.

Peat layers

For explanation see peat.

Root penetration

Root penetration is present at a place where there is much coverage by plants above the ground level moreover root penetration is the base for organic layers.

Sand layers

For explanation see sand.

Shell layers

Steeply inclined layers

Inclined layers exist due to the pressure of continental plates or due to the movement of soil/rock in which the layers are tilted. After these processes the new sediments are deposited with another orientation than the ones underneath.

Stone layers

For explanation see pebbles.

Twisted sand layers

Sand is a sediment which is very mobile. This results in the fact that sand layers can be formed by less pressure and easily deformed.

References

NEN-EN-ISO 14688-1:2019

Layering

Image	Layering

Contents

Layer Transitions

Layer thickness

Examples

Clay layers

Detritus layers

Gravel layers

Gyttja layers

Heterogeneous

Homogeneous

Loam layers

Peat layers

Root penetration

Sand layers

Shell layers

Steeply inclined layers

Stone layers

Twisted sand layers

References

Layering