Editing Thermal history modelling

'''Thermal history modelling''' is an exercise undertaken during [[basin modelling]] to evaluate the temperature history of stratigraphic layers in a [[sedimentary basin]].<ref>{{Cite journal |last1=Vermeesch |first1=Pieter |last2=Tian |first2=Yuntao |date=2014-12-01 |title=Thermal history modelling: HeFTy vs. QTQt |journal=Earth-Science Reviews |language=en |volume=139 |pages=279–290 |doi=10.1016/j.earscirev.2014.09.010 |bibcode=2014ESRv..139..279V |issn=0012-8252|doi-access=free }}</ref>

The thermal history of a basin is usually calibrated using thermal indicator data, including [[vitrinite]] reflectance and [[fission track]]s in the [[mineral]]s [[apatite]] and [[zircon]].

The temperatures undergone by rocks in a sedimentary basin are crucial when attempting to evaluate the quantity, nature and volume of [[hydrocarbon]]s ([[fossil fuel]]s) produced by [[diagenesis]] of [[kerogen]]s (a group of chemicals formed from the decay of organic matter).

[[Fourier's law]] provides a simplified one-dimensional description of the variation in heat flow ''Q'' as a function of [[thermal conductivity]] ''k'' and thermal gradient ''dT''/''dz'':

:<math>Q=-k\frac{dT}{dz}</math>

(The minus sign indicates that heat flows in the opposite direction to increasing depth, that is, towards the Earth's surface.)

If the assumptions used to justify this simplified approximation (i.e. steady-state [[heat conduction]], no [[convection]] or [[advection]]) are accepted, we define the simple 1-dimensional heat diffusion equation where temperature ''T'' at a depth ''z'' and time ''t'' is given by the equation:

:<math>T_{z,t} = T_{t}^0 + Q_t \int_0^z\frac{dz'}{k_{z'}}</math>
where ''T''<sub>t</sub><sup>0</sup> is the surface temperature history, ''Q''<sub>''t''</sub> is the [[heat flow]] history and ''k'' is thermal conductivity.  The integral thus represents the integrated thermal conductivity history of a 1-dimensional column of rock.

Thermal history modelling attempts to describe the temperature history ''T''<sub>z,t</sub> and therefore requires a knowledge of the burial history of the stratigraphic layers which is obtained through the process of [[back-stripping]].

== References ==
{{Reflist}}

==See also==
*[[Petroleum geology]]

{{DEFAULTSORT:Thermal History Modelling}}
[[Category:Petroleum geology]]
[[Category:Sedimentology]]


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