Download presentation

The
Development of
Contact
Metamorphism
About a Cooling
Dyke
Felix Boschetty
Aims of the Project
• To model the development of metamorphic zones around a dyke that is
emplaced at the surface
• Develop the discretised 2D heat equation by varying the model’s thermal
properties and implementing progressive metamorphism
• Show how different rock types affect the degree of metamorphism
• I have two MatLab Codes. The first shows how the different thermal
properties of rocks affects the 1D thermal distribution. The second
produces a 2D thermal d
• METAMORPHISM refers to changes in a rock’s mineralogy, texture, and/or
composition that occur predominantly in the solid state under conditions
between those of diagenesis and large-scale melting
Winter, J.D., 2013, Principles of Igneous and Metamorphic
Petrology: Harlow, United Kingdom, Pearson Education
Title image from: www.odysseycoachtours.co.uk/giantscauseway-cruise-tours
Contact Metamorphism
Contact metamorphism occurs adjacent to igneous intrusions,
principally as a result of the thermal (and possibly metasomatic) effects
of hot magma intruding cooler shallow rocks.
FACTORS THAT AFFECT CONTACT METAMORPHISM
Intrusion Temperature, Time, Country-Rock Mineralogy, Pressure,
Geothermal Gradient, Fluid Content of Both Lava and Country Rock,
Type and Volume of Lava, Number of Stages of Intrusion.
Winter, J.D., 2013, Principles of Igneous and Metamorphic
Petrology: Harlow, United Kingdom, Pearson Education
Thermal Properties of Different Rocks
𝜂=
𝑘
𝜌 ∗ 𝐶𝑝
Rock Type
Density
( g.cm-3)
Limestone
2.62
Sandstone
Shale
Where 𝜂 is thermal diffusivity, 𝑘 is thermal conductivity,
𝜌 is density, and 𝐶𝑝 is heat capacity
Thermal Conductivity
(10-3 cal.cm-1.s-1.oC-1)
Heat Capacity
(cal.g-1.oC-1)
Thermal Diffusivity
(10-3 cm2.s-1)
Metamorphism T
(oC)
6.75
0.210
12.18
500
2.65
7.75
0.205
16.45
400
2.68
5.13
0.197
9.26
300
Eppelbaum, L.V., Kutasov, I., and Pilchin, A., 2014, Applied Geothermics: Berlin, Springer-Verlag Berlin and
Heidelberg GmbH & Co. KG.
Winter, J.D., 2013, Principles of Igneous and Metamorphic Petrology: Harlow, United Kingdom, Pearson
Education
The 1D Heat Distribution of Three Rock Types
After One Year
Increase in Final Temperature
Animation: The Contact Metamorphism
Produced in Slate After One Year
The Contact Metamorphism of Different
Country Rock After One Year
Increase in Size of Metamorphic Aureole