Data Publication

What controls sill formation: an overview from analogue models

Sili, Giulia | Urbani, Stefano | Acocella, Valerio

GFZ Data Services

(2019)

Descriptions

This data publication includes movies and figures of twenty-six analogue models which are used to investigate what controls sill emplacement, defining a hierarchy among a selection of the proposed factors: compressive stresses, interface strength between layers, rigidity contrast between layers, density layering, ratio of layer thickness, magma flow rate and driving buoyancy pressure (Sili et al., 2019). Crust layering is simulated by pig-skin gelatin layers and magma intrusions is simulated by colored water. The experimental set-up is composed of a 40.5 X 29 X 40 cm3 clear-Perspex tank where a mobile wall applies a deviatoric compressive stress (C, in Table 1) to the solid gelatin (Figure 1). In each experiment is imposed two layers with different density and rigidity, separated by a weak or strong interface, excluding two experiments characterized by homogeneous gelatin (experiment 4 and 12). Three different rigidity contrast (1, 1.3, 1.8) between the two layers are imposed, defined as the ratio between the Young’s moduli of the upper (Eu) and lower (El) layer. By using NaCl and gelatin concentration, two layers with same rigidity but different densities are obtained, investigating the influence of the density contrasts on sill emplacement. The effects of the ratio between layer thicknesses (i.e. the ratio between upper and lower layer thickness: Thu/Thl) was simulated by changing only the thickness of the upper layer; while magma flow rate are studied changing the flow rate of peristaltic pump. Water density was increased by adding NaCl to analyze the effect of changing driving buoyancy pressure (Pm) that depends on the density difference between host rock and magma (Δρ), gravitational acceleration (g) and intrusion length (H). In the table different colors indicate the experiment result: black = dike; red = sill and blue = sheet. The here provided material includes time-lapse movies showing intrusion propagation of the twenty-six models with a velocity of 5 times higher compared to the real time (1 second in the movie is 25 real seconds). These visualizations are side (XZ or YZ plane in Figure 1) and/or top views (XY plane in Figure 1).

Keywords

Originally assigned keywords

buoyancy pressure

intrusion

magmatic process

EPOS

multi-scale laboratories

analogue models of geologic processes

analogue modelling results

earth interior setting > crust setting > continental-crustal setting > upper continental crustal setting

magmatic process > intrusion

dike

sill

Water

Gelatine > Pig skin

Glass/Plexiglas box > Glass/Plexiglas box (cm scale)

Generic camera

Young modulus

Yield stress

Fracture toughness

Density

Corresponding MSL vocabulary keywords

dike

camera

Young's modulus

poroelastic deformation

Young's modulus

yield strength

fracture and crack toughness

MSL enriched keywords

Modeled geomorphological feature

volcanic landforms

dike

Ancillary equipment

model surface monitoring (2D)

camera

Measured property

elasticity

Young's modulus

Inferred deformation behavior

deformation behaviour

poroelastic deformation

Measured property

elasticity

Young's modulus

mechanical strength

yield strength

mechanical strength

yield strength

fracture and crack toughness

igneous rock - intrusive

magma

analogue modelling material

elastic modelling material

natural elastic material

gelatin

MSL enriched sub domains i

analogue modelling of geologic processes

rock and melt physics

Source

https://dataservices.gfz-potsdam.de/panmetaworks/showshort.php?id=escidoc:3961899

Source publisher

GFZ Data Services