Earth and Planetary Science Letters 223 (2004) 395 – 413
www.elsevier.com/locate/epsl
Thermal consequences of thrust faulting: simultaneous versus
successive fault activation and exhumation
M. ter Voorde *, C.H. de Bruijne, S.A.P.L. Cloetingh, P.A.M. Andriessen
Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, 1081HV Amsterdam, The Netherlands
Received 30 June 2003; received in revised form 5 April 2004; accepted 22 April 2004
Available online
Abstract
When converting temperature – time curves obtained from geochronology into the denudation history of an area, variations
in the isotherm geometry should not be neglected. The geothermal gradient changes with depth due to heat production and
evolves with time due to heat advection, if the deformation rate is high. Furthermore, lateral variations arise due to topographic
effects. Ignoring these aspects can result in significant errors when estimating denudation rates. We present a numerical model
for the thermal response to thrust faulting, which takes these features into account. This kinematic two-dimensional model is
fully time-dependent, and includes the effects of alternating fault activation in the upper crust. Furthermore, any denudation
history can be imposed, implying that erosion and rock uplift can be studied independently to each other.
The model is used to investigate the difference in thermal response between scenarios with simultaneous compressional
faulting and erosion, and scenarios with a time lag between rock uplift and denudation. Hereby, we aim to contribute to the
analysis of the mutual interaction between mountain growth and surface processes. We show that rock uplift occurring before
the onset of erosion might cause 10% to more than 50% of the total amount of cooling.
We applied the model to study the Cenozoic development of the Sierra de Guadarrama in the Spanish Central System,
aiming to find the source of a cooling event in the Pliocene in this region. As shown by our modeling, this temperature drop
cannot be caused by erosion of a previously uplifted mountain chain: the only scenarios giving results compatible with the
observations are those incorporating active compressional deformation during the Pliocene, which is consistent with the
ongoing NW – SE oriented convergence between Africa and Iberia.
D 2004 Elsevier B.V. All rights reserved.
Keywords: thermal history; uplift; faulting; topography; erosion; exhumation
1. Introduction
Since 1990, when Molnar and England [1] posed the
‘chicken and egg’ question for the relation between Late
* Corresponding author. Tel.: +31-20-4447343; fax: +31-206462457.
E-mail address: [email protected] (M. ter Voorde).
0012-821X/$ - see front matter D 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.epsl.2004.04.026
Cenozoic uplift of mountain ranges and global climate
change, the discussion about the mutual interaction of
mountain uplift and surface processes received considerable attention. Numerous authors have been working
on this topic, from different points of perspective. For
example, depositional patterns in foreland basins have
been analyzed [2] and numerical models describing the
interaction between erosion and mountain growth have
396
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 1. The effect of lateral heat transport is that cooling of a rock sample might begin before the onset of erosion. In these cases, the onset of a
cooling phase (A) does not reflect the onset of exhumation (B, scenario 1) but rather the onset of uplift of a rock column relative to its
surroundings (C, scenario 2).
been developed [3,4], searching to answer the question
whether enhanced erosion is the primary cause of mountain uplift or mountain uplift is the primary cause of
enhanced erosion. Precise dating of these processes is an
essential contribution to this debate. For this, the strength
of using thermochronology has been demonstrated by
numerous authors (e.g. [5 –12]).
In the past, thermochronologically derived cooling
rates were often reported as erosion rates [13]—which
were in turn considered to be identical to uplift rates.1
The amounts of erosion estimated were obtained by a
direct conversion of the cooling measured in the samples, according to a constant and linear geotherm, e.g.
[14]. This approach, however, neglects the following
effects: (1) heat advection, which might cause the geotherm to change with both depth and time, depending on
the rate of deformation, (2) heat production, resulting in
a decrease of the geothermal gradient with depth, (3)
vertical as well as lateral variations in conductivity,
1
Throughout this paper, we will use the terms ‘denudation’ and
‘exhumation’ to describe the upward movement of a rock sample
with respect to the surface, due to the removal of overlying material,
which we call ‘erosion’. By ‘uplift’, we mean the upward movement
of a rock column with respect to a fixed level.
changing the geothermal gradient in both directions,
and (4) the lateral cooling effect of topographic relief,
which might cause a decrease in temperature for samples in locally uplifted blocks, without any erosion
taking place [15 – 18]. Ignoring heat advection during
uplift produces a potential underestimation of the
amount of denudation and/or a delay in the estimated
onset of tectonic activity. Also, the neglect of heat
production, taking the surface temperature gradient as
representative for the linear geotherm across the entire
crust, yields an underestimation of the amount of
erosion. On the other hand, ignoring lateral cooling
might cause an overestimation of the amount of erosion.
The effect of lateral heat loss through mountain
flanks in areas with a large topographic relief is that
cooling of a rock sample might begin before the onset
of erosion. In these cases, the onset of a cooling phase
does not reflect the onset of exhumation, but rather the
onset of uplift of a rock column relative to its surrounding (Fig. 1). For the chicken-and-egg problem mentioned above, the distinction between these scenarios is
of major importance.
Considering the effects of heat advection, heat production and topographic relief in the analysis of cooling
curves will gain importance with the increase of resolv-
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
ing power of dating techniques, for example, due to the
recent rapid development of (U –Th)/He thermochronology utilizing apatites, e.g. [19 – 22]. For apatite fission track analysis, the errors that can be caused by the
assumption of a constant and linear geotherm are already
large: especially in young, tectonically active mountain
belts, exhumation rates may be overestimated by a factor
of 2 or more [16]. As shown by Mancktelow and
Grasemann [16], in regions of rapid exhumation and
significant relief, reliable estimates can only be obtained
using numerical models.
In the past few years, various authors thus have
presented numerical models aiming to interpret cooling
curves. For example, Mancktelow and Grasemann [16]
modeled the time-dependent behavior of isotherms
below an actively eroding topography. Stüwe and
Hintermüller [17] showed the importance of including
asymmetrical erosion, assuming a thermal steady state,
and Braun [23] predicted the evolution of the temperature below an evolving, finite amplitude surface
topography. None of these authors included faults in
the numerical models. Nevertheless, fault movements
are among the most important mechanisms for deformation in the upper crust, and strongly affect the
thermal evolution by creating a high lateral gradient
across the fault [24 – 26]. Furthermore, movement of
fault blocks causes a lateral shift in position of the rock
sample in which the temperature is recorded. In areas
with significant horizontal variations in the temperature
field, not only the vertical but also the horizontal
movement of a rock sample has consequences for its
cooling history. This effect is therefore, again, especially important in regions with a rugged topography.
In this paper, we present a numerical model that
simulates movements along thrust faults and calculates the thermal response of the lithosphere, taking
into account heat advection, heat production and
topography. The model offers the possibility to impose any denudation history, allowing us to analyze
erosion and uplift as mutually independent factors.
We use the model to investigate situations that are
not in steady state, and specifically to analyze the
thermal effect of the existence of a time lag between
the creation of topography by uplift of a fault block and
its removal by erosion. The differences between various scenarios are studied by focusing on resulting
cooling curves in synthetic rock samples included in
the model.
397
The second part of the paper describes an example of
an application of the model on the Sierra de Guadarrama
in Central Spain, a mountain range with a maximum
relief of f 1400 m over a distance of f 10 km, and
Pliocene to recent denudation rates up to 2 km/My
[14,27]. This, combined with the vast amount of independent structural, sedimentary and thermochronological data available for both the Sierra and its bounding
basins [14,27 – 36], makes the area well suited for a case
study of the interplay between thermal effects of uplift
and erosion. We use our numerical model to investigate
the possible existence of a time-gap between the onset of
uplift and the onset of accelerated cooling in the Pliocene, as derived from fission track analysis [14,27].
2. The numerical model
We developed a two-dimensional model, simulating lithospheric shortening and calculating the associated thermal field. Details of the thermal aspects of
the model are described by ter Voorde and Bertotti
[24], who used a similar model for simulating extension along faults. New aspects of the modified version
of the model presented here is that contractional
deformation is simulated and that surface processes
can be (de-)activated by the user.
The deformation is described by the movement of
material along faults in the upper crust, combined with
a more gradually distributed thickening in the lower
lithosphere (Fig. 2). Hanging wall movement occurs
according to the vertical shear mechanism, i.e. the
horizontal velocity vx = the compression rate, given as
input by the user of the model, and the vertical velocity
vy = vxtan(u), where u = the dip angle of the fault. The
footwall is assumed to be immovable. When dealing
with several faults, we simply add the velocity fields
resulting from each separate fault [37,38]. In this case,
the faults positioned in the hanging wall of their
neighbors will change position with the material in
which they are situated (see Fig. 2). Calculations are
performed using the finite difference method on a
static rectangular grid, which is coarsened on the lower
side of the model. A second, moving grid is used to
trace the paths followed by the material-points.
Obviously, the relation between the amount of
horizontal compression and the resulting amount of
fault-block uplift is largely dependent on the fault
398
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 2. Cartoon of the numerical model, in which time is increasing and thrusts develop from (A) to (C). Compression is accommodated by
vertical shear movement along faults in the upper crust, combined with more gradually distributed thickening in the lower lithosphere.
geometry. In our model, a different geometry can
be chosen for each fault, although all the faults
should flatten out (i.e. get horizontal) at the same
depth. Beneath this ‘detachment level’ compression
is simulated as a sinusoidal thickening, fulfilling the
condition of volume conservation. At the basement
surface, faults can be chosen to become horizontal,
resulting in fault-bend folding, or to propagate
upward with a constant dip angle. This last option
is only reasonable if sediments are deposited on the
footwall, or if the resulting topography is removed
by erosion instantaneously.
The model has the possibility to activate the faults
independently of each other, and with various shortening rates. Furthermore, these shortening rates may
change with time. To our knowledge, this possibility
has not been incorporated in thermal models for
lithospheric compression before.
In each modeling timestep, the new temperature
distribution resulting from heat advection, heat conduction and heat production is determined. Heat
production is restricted to one layer, in which its value
is assumed to be constant. Although radiogenic heat
production would be better approached by an exponential decrease with depth, the critical information
Table 1
Thermal modeling parameters, chosen to mimic the situation in the
Sierra de Guadarrama
Surface temperature
Base temperature
Base depth
Thermal diffusivity crust
Thermal diffusivity sediments
Thickness heat producing layer
Heat production in HP layer
10 jC
592 jC
50 km
10 6 m2/s
0.8 10 6 m2/s
12 km
4.8 AW/m3
Note that the heat production is much higher than average.
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 3. Definition of the surface line. In every timestep, where the
modeled geometry is higher than the surface line, material above the
line is removed, where the modeled geometry is lower than the
surface line, sediments are added. For the thermal calculations, this
implies a change in the position of the upper boundary where the
temperature is fixed to Tsurface.
for the resulting geotherm is the total amount of heat
generation, and not its vertical distribution [39]. When
the material moves, the heat-producing layer deforms,
which is taken into account in our model. Thermal
boundary conditions are constant temperatures at the
surface and at the base of the model (Table 1). The
significant influence of thermal blanketing, due to the
low conductivity of the sediments, has been firmly
established [24,40,41] and is therefore included. The
effect of frictional heating is ignored. For high slip
399
rates (>5 cm/year), frictional heating would result in a
temporarily but significant increase of temperatures
close to the fault plane. For slip rates lower than 1 cm/
year, the temperature increase due to frictional heating
is shown to be negligible [42].
Synthetic rock samples can be defined, that move
along with the crustal material, and in which temperature
is measured during time. Erosion and sedimentation are
activated by defining a ‘surface line’ in the model (Fig.
3). All the material above this line is removed, gaps
beneath it are filled with sediments. Furthermore, the
surface line defines the upper boundary of the thermal
model—i.e. the line along which the temperature is fixed
to Tsurface. The surface line is defined by the user of the
model for specific timesteps, and deforms with time by
linear interpolation between these moments.
The concept of the surface line does not result in mass
conservation. Instead, this method offers the possibility
to study the effect of any chosen denudation history, or to
include known sedimentation or denudation rates as
constraints. A more process-based calculation of erosion
and sedimentation would not offer this possibility.
Furthermore, due to the uncertainties of all the parameters involved, it would not provide more confident
results.
Fig. 4. Comparison of modeling results to analytical solutions. In the modeling experiments we used a grid-spacing of 0.5 km and modeling
timesteps of 1 Myr. (A) The shape of the steady-state 100 jC isotherm underneath a sine-shaped topography with an amplitude of 3 km and a
wavelength of 20 km, denuding at the rates of U = 10, 100, 500 and 1000 m/Ma. Solid lines: Modeling results. Dashed lines: Analytical
solutions by Stüwe et al. [15]. (B) Cooling histories of samples from different initial depths during rock uplift and exhumation at a rate of 1 mm/
year, assuming no heat generation, an original 25 jC/km geothermal gradient, and constant temperature boundary conditions of 0 jC at 0 km
and 2500 jC at 100 km. Solid lines: Modeling results. Dashed lines: Analytical solutions by Mancktelow and Grasemann [16].
400
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
The validity of the modeling results concerning
the thermal effects of faulting and the interplay
between advection and conduction has been demonstrated in earlier papers [24,38]. New aspects of the
model described here are the inclusion of uplift and
the possibility to create an irregular topography. We
therefore carried out two extra tests, considering the
interplay between uplift, advection and eroding topography. In these tests, we did not apply compression along the faults, but applied an artificial amount
of constant uplift of a 100-km-wide block of crustal
material. In this way, the modeling results could be
compared to analytical solutions published by Stüwe
et al. [15], showing the influence of an irregular
topography on the isotherms, and by Mancktelow
and Grasemann [16], who illustrated the effect of
time-dependent advection. The results of these comparisons are shown in Fig. 4. The maximum deviation between the modeled and analytically calculated
depth of the isotherms turned out to be less than 4%.
The absolute difference is largest for low uplift rates
(e.g. 10 m/Ma in Fig. 4A), which is due to the fact
that for these cases the amount of denudation in one
numerical timestep is less than the grid-spacing of
the model.
3. Successive fault block uplift and erosion;
modeling results
In order to test the influence of simultaneous
versus successive fault-block uplift and erosion, several model runs are carried out. In the first set of
model runs, fault-block uplift and erosion were assumed to occur simultaneously, resulting in a constant
(flat) topography (scenario 1 of Fig. 1). In the second
set of model runs, we assumed a period of rock uplift
without erosion, implying the creation of a topographic high, followed by a period of erosion without any
uplift (scenario 2 of Fig. 1). Fault dimensions, total
amount of shortening, and thermal parameters were
chosen to mimic the situation in the Sierra de Guadarrama (SdG, see below). This allows us to extend
our general conclusions to the specific case of this
region.
We used a simple geometrical setting, consisting of
a crust containing one straight fault with dimensions
similar to that of the Southern Border Fault of the
SdG, along which we applied a total horizontal
shortening of 3 km [14,34] (see Fig. 5A). Other model
parameters are given in Table 1. It should be noted
that the assumed heat production is a factor of 2– 3
times higher than the average value for the upper
crust. This is done in order to mimic the high surface
heat flow as measured in the SdG [43], and can be
justified by the high concentration of Uranium
detected in the rock samples. The implication is that
the synthetic results should be viewed as an endmember of the spectrum of possible values for heat
production. In order to illustrate the effect of this, the
other end-member (i.e. the case without heatproduction) is modeled as well (Fig. 6).
3.1. The influence of varying periods and rates of
uplift and erosion
Fig. 5 shows the results for the first synthetic tests.
The thermal structure at the start of each model run is
shown in Fig. 5A (upper panel). The lower panel of
Fig. 5A displays the isotherms after deformation has
occurred in the absence of erosion, which is at the end
of the uplift phase in scenarios 4, 5 and 6, assuming
that the steady state situation is accomplished. All the
material above a reference level (i.e. the surface at the
start of the modeling) is removed during the simulations. This results in a laterally varying amount of
erosion, with a maximum of 3 km in the central region
of the mountain, between x = 18 km and x = 27 km.
The samples in which the temperature is monitored
are all chosen to be situated in this central part,
leading to 3 km of erosion above samples A, B and
C. Since it is seated in the footwall, sample D is
positioned at its original depth after each model run.
For the 6 different scenarios, the total time from midMiocene to present day (16 My) was subdivided into
various periods of uplift, quiescence, or erosion, as
given in Table 2. Fig. 5B gives the resulting T –t paths
in the synthetic rock samples for scenarios 1, 2 and 3,
all assuming simultaneous uplift and erosion. In scenarios 4, 5 and 6 shown in Fig. 5C, we applied first a
stage of compression, and then a stage of erosion.
The T –t curves show the following features:
– When considering coeval uplift and erosion (Fig.
5B), the cooling curves of the samples in the
hanging wall have the same shape as the steady-
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
401
Fig. 5. Results of synthetic modeling of compression along one fault. Fault dimensions are chosen similar to that of the Southern Border Fault of the Sierra de Guadarrama. The
different modeled scenarios are given in Table 2. Heat production is included (see Table 1). (A) Start configuration and resulting crustal geometry after 3 km of compression. The
dashed line represents the level to which erosion occurs (B) T – t curves for scenarios 1, 2 and 3, where uplift and erosion occurred simultaneously. (C) T – t curves for scenarios 4, 5
and 6, where a period of uplift without erosion was followed by a period of erosion of all the material, using a constant erosion rate (D) T – t curves for simultaneous uplift and
erosion, with a compression rate of 6 km/My (i.e. 10 times higher than in scenarios 1 and 3).
402
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 6. Results of synthetic modeling of compression along one fault. Same as Fig. 5C, but without heat production. (A) Thermal gradient
is 12 jC/km; (B) thermal gradient is 28 jC/km.
state geotherm as shown in Fig. 5A, which is
almost linear for the upper 3 km. This is true as
long as the conduction of heat is able to keep up
with the advection, which is the case if the Péclet
number, Pe, is smaller than 1. Assuming the
thermal diffusivity j = 10 6 m2/s, and taking the
length scale L = 12 km, Pe ¼ t
v Lj < 1 if the
compression rate v is greater than about 2.6 mm/
year. At higher deformation rates, when advection
starts to play a role, the rate of cooling will
increase with time, due to the increasing temperature gradient in the near-surface (see Figs. 4B and
5D). The very small amount of cooling in sample
D in the footwall is caused by the thickening of the
lower layer of the crust (i.e. beneath the detachment level), slightly downwarping the isotherms
beneath the fault.
– When applying successive uplift and erosion (Fig.
5C), another pattern appears. A considerable
amount of cooling already occurs during the uplift,
although there is no denudation involved yet. This
is due to lateral heat flow through the flanks of the
uplifted thrust front, and therefore related to the
distance from these flanks. Sample C, which is
closest to the flank, shows the largest amount of
cooling during the uplift phase. The sample in the
footwall shows increasing temperatures during the
deformation, because it is buried and its relative
depth becomes 3 km larger.
– For scenarios 5 and 6, in which a period of
quiescence is simulated between the uplift and
the erosion, temperatures appear not to change
during these periods, indicating a steady-state
situation. Apparently, the rate of modeled uplift
was low enough to allow for thermal conduction
to keep up with advection during the tectonic
movement. This is in agreement with the Péclet
number calculations as shown in the above.
Furthermore, it should be realized that thermal
relaxation in a 2D model including lateral heat
transport occurs much faster than in one-dimensional models [24 –26].
– During erosion, the thermal structure of the
lithosphere changes from the situation shown in
the lower panel of Fig. 5A back to the structure
shown in the upper panel. This causes a
steepening of the geotherm at the position of the
samples, resulting in a curved, concave upward
T –t curve, with the rate of cooling increasing
with time.
– From the cooling curves of scenarios 4, 5 and 6, we
can conclude that, depending on the distance to the
fault (from 3.15 km for sample A to < 0.5 km for
sample C), 29 –44% of the cooling occurs already
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Table 2
Input for synthetic modeling of uplift and erosion for six scenarios,
with various periods of uplift, periods of denudation, and rates of
denudation
Scenario
no.
Uplift
period
(Ma)
Uplift
rate
(mm/year)
Denudation
period
(Ma)
Denudation
rate
(mm/year)
1
2
3
4
5
6
16 – 0
16 – 11
5–0
16 – 5
16 – 5
16 – 11
0.19
0.6
0.6
0.27
0.27
0.6
16 – 0
16 – 11
5–0
5–0
1–0
5–0
0.19
0.6
0.6
0.6
3.0
0.6
Amounts of uplift and denudation represent the maximum values, as
present in the central part of the uplifted area. Since all synthetic
rock samples are positioned in this region, the specified amounts
can also be regarded as the amounts of uplift and denudation of each
modeled sample. The total amount of uplift and denudation is
identical for all scenarios (i.e. maximum 3 km). Results of the
modeling are shown in Fig. 5.
during the uplift in the absence of erosion. The
quantification of this cooling caused by uplift is
done for a more extended range of parameters in
Section 3.2.
– For samples at distances V 1 km from the fault, the
only scenario that results in Pliocene accelerated
cooling from within the partial annealing zone is
the one representing simultaneous deformation and
denudation from the Pliocene to present day (i.e.
scenario 3).
As mentioned already, these experiments should be
viewed as an end-member study, considering the high
heat production value assumed. A high heat production value will result in relatively high thermal gradients in the upper crust and relatively low gradients in
the lower crust and lithosphere. This will adversely
influence the amount of cooling occurring during
uplift, in the absence of erosion. This is illustrated in
Fig. 6, showing results of the same experiments for the
other end-member, that is, without heat production. In
Fig. 6A, scenarios 4, 5 and 6 are repeated with the
same thermal parameters as in Table 1, but without
heat production, yielding a thermal gradient of 12 jC/
km. Also, Fig. 6B shows these scenarios without heat
production—but this time the bottom temperature is
changed in order to get the same surface thermal
gradient as in the scenarios including heat production
403
(i.e. 28 jC/km). As expected, it appears that the
amount of cooling solely due to rock uplift becomes
relatively larger. In addition, we observe that the only
difference between Fig. 6A and B is the vertical scale
of the figure.
3.2. Cooling caused by topography—a parameter
study
3.2.1. The amount of topographic cooling
In the following experiments, we calculated the
maximum amount of cooling of a rock sample
caused solely by uplift of a fault block (i.e. without
any erosion). Hereafter, we will call this temperature
drop due to rock uplift ‘topographic cooling’. The
absolute amount of topographic cooling is given by
(Tstart Ttopo), where Tstart = the initial temperature of
the sample, and Ttopo = the temperature of the sample
in a steady-state thermal field after the creation of
topography by uplift of the fault block (as in Fig.
5A, lower panel). Fig. 7 shows the values of Tstart
and Ttopo for several samples as a function of their
initial depths. Each point on a curve in this figure
represents the temperature of the sample after the
specified amount of uplift has taken place and the
steady state situation is achieved. In these experiments, we have chosen the initial depth of the
samples to be equal to the total amount of rock
uplift. This to assure that, after denudation of the
created topography, the sample arrives at the surface.
In Fig. 7A – C, the same fault geometry was used as
in the former tests—i.e. the configuration depicted in
Fig. 5A. The amount of uplift, and therefore also the
initial depth of the rock samples, was varied between
1 and 6 km. Each figure thus represents six model
runs. Fig. 7D – F depicts the results for a less steep
fault, dipping 30j. The three modeled amounts of
shortening were 1.73, 3.46 and 5.20 km, resulting in
1, 2 and 3 km of maximum uplift, respectively. In
Fig. 7A and D, heat production was included (see
Table 1), Fig. 7B and E are without heat production
and assuming a thermal gradient of 12jC/km, and
Fig. 7C and F are without heat production assuming
a geothermal gradient of 28 jC/km.
The amount of topographic cooling can be
extracted from Fig. 7 by measuring the difference
between Tstart and Ttopo. For example, the amount
of topographic cooling of a sample 0.5 km from
404
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 7. Results of a parameter study. The temperature of the rock sample after sole uplift without denudation is depicted, as a function of the
initial depth of the sample (which is equivalent to the amount of uplift simulated by the model run). Various lines represent various samples, at
given distances from the fault tip at the end of the model run. (A) Fault geometry as in Fig. 5A, thermal parameters as in Table 1. (B) Fault
geometry as in Fig. 5A, no heat production, initial thermal gradient of 12 jC/km. (C) Fault geometry as in Fig. 5A, no heat production, initial
thermal gradient of 28 jC/km. (D) Fault dip of 30j, thermal parameters as in Table 1. (E) Fault dip of 30j, no heat production, initial thermal
gradient of 12 jC/km. (F) Fault dip of 30j, no heat production, initial thermal gradient of 28 jC/km.
the fault tip, with an initial depth of 3 km, in a
setting without heat production and a geothermal
gradient of 28 jC/km, is equal to 94 62 = 32 jC
(Fig. 7C).
The amount of compression and the fault geometry influence the geometry of the resulting topo-
graphic high, as is illustrated in Fig. 8. Important for
the amount of cooling is the height – width ratio of
the uplifted mountain block, which is here defined as
the width of the central part where the maximum
amount of uplift occurs, divided by the height of this
area (Fig. 8).
Fig. 8. The height – width ratio of the uplifted fault block is dependent on the amount of shortening and uplift as well as the fault geometry.
Synthetic rock samples are all chosen to be positioned in the central region of the mountain, where constant maximum uplift takes place.
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 9. Results of a parameter study. Contour lines depict the amount of cooling due to sole uplift without denudation, as a percentage of the total amount of cooling after erosion to
base level. X-axis: The distance between the sample and the fault tip at the end of the model run. Y-axis: The initial depth of the sample. (a) Fault geometry as in Fig. 5a, thermal
parameters as in Table 1. (b) Fault geometry as in Fig. 5a, no heat production, initial thermal gradient of 12 jC/km. (c) Fault geometry as in Fig. 5a, no heat production, initial thermal
gradient of 28 jC/km. (d) Fault dip of 30j, thermal parameters as in Table 1. (e) Fault dip of 30j, no heat production, initial thermal gradient of 12 jC/km. (f) Fault dip of 30j, no heat
production, initial thermal gradient of 28 jC/km.
405
406
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
3.3. The percentage of topographic cooling
Fig. 9 presents the amount of topographic cooling as
a percentage of the total cooling after denudation of the
sample, (Tstart Ttopo)/(Tstart Tsur), where Tsur = the
final temperature after denudation, when the sample
has reached the surface. Modeled scenarios are identical to Fig. 7. Temperature changes were monitored in
eight synthetic rock samples, at distances varying from
0.5 to 7 km from the fault. In order to make a mutual
comparison possible, all the samples must comply with
the condition that they are positioned in the central part
of the fault block where the maximum amount of uplift
occurs. For very high amounts of compression and
uplift, we had to withdraw the samples the furthest
away from the fault, since they did not fulfill this
condition anymore (see Fig. 8B).
For small distances (i.e. < 3 km) between the
samples and the fault tip, the figure clearly exhibits
decreasing percentages of topographic cooling for
increasing distances between the samples and the
fault. Consider, for example, the samples with the
initial depth of 3 km in Fig. 9A, for which the
topographic cooling is shown in Fig. 5A (lower
Fig. 10. (A) Geological sketch map of Iberia (after de Bruijne and Andriessen [14]; Van Wees [57]). SCS = Spanish Central System. The square
gives the position of Fig. 1B. (B) Geological map of the Sierra de Guadarrama. Small circles are locations where fission track samples were
taken. (C) Cross section AAV through the Sierra de Guadarrama, based on field data [14] and well log information [58]. Black dots indicate
(projected) rock samples used for the fission track analysis. After De Bruijne and Andriessen [14].
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
panel). For this model run, the percentage of
topographic cooling decreases from 44% at 0.5
km from the fault, to 29% at 3 km from the fault.
This is caused by lateral cooling through the mountain flanks. For samples further from the fault tip,
the lateral cooling effect decreases and then disappears, until the effect of the flank at the other side
of the mountain chain becomes visible and increasing percentages of topographic cooling emerge. As
a result, for each simulated scenario, the lowest
percentage of topographic cooling is found in the
centre of the uplifted area (i.e. at 4.5 km from the
fault tip in the example given above, see also Fig.
8A). Note that the position of this centre is closer to
the fault tip when the amount of uplift is higher
(see also Fig. 8B).
Another outcome from our modeling results is that
an increase in fault-block uplift apparently not only
results in an (absolute) increase in the total amount of
cooling, but also in an increase in the percentage of
topographic cooling. This is caused by the increasing
height/width ratio of the resulting mountain.
The striking similarity between Fig. 9B and C
implies that the percentage of topographic cooling is
not dependent on the absolute amount of topographic cooling in a sample: although the absolute
amount of topographic cooling in the model runs
depicted in Fig. 9C is more than two times higher
than for those in Fig. 9B (see Fig. 7), the percentages of topographic cooling remain exactly the
same. This is in agreement with the similarity
between Fig. 6A and B.
The maximum percentage of topographic cooling
obtained from all modeled scenarios is 57%, which we
found for the scenarios without heat production, an
amount of uplift of 6 km, and a rock sample at 1 km
from the fault tip.
Fig. 9D – F depicts the results for a fault, dipping
30j. Due to the smaller fault dip, the height/width
ratio of the uplifted mountain is smaller compared
to in the previous model runs (see Fig. 8), which is
reflected in the lower fractions of topographic cooling for these cases. As also shown in Fig. 8, the
width of the mountain block itself is larger for this
fault geometry. This causes the centre of the
uplifted fault block to be further away from the
fault tip. Other features are comparable to those of
Fig. 9A – C.
407
Summarizing, we conclude that the amount of
cooling that can occur already without any denudation is a factor that should not be neglected when
studying T – t paths obtained from thermochronological methods.
4. Application of the model: the example of the
Sierra de Guadarrama
4.1. The Pliocene cooling event
The Sierra de Guadarrama (Fig. 10) forms part of
the Spanish Central System (SCS), an ENE – WSW
trending intraplate relief zone in Iberia of about 40
km wide and 500 km long, separating the Duero
Basin in the northwest from the Madrid Basin in the
southeast. Elevations of the SCS are up to almost
2600 m in the central part. Its development resulted
for a large part from the compressive regime in the
mid-Tertiary, caused by stresses acting from the
Pyrenean and Betic borders of Iberia. These stresses
originated from the convergence of the African and
European plates and the subsequent accretion of
Iberia to both Europe and Africa, from the Eocene
onward, e.g. [44].
Based on a fission track study, De Bruijne and
Andriessen [14,27] proposed a conceptual model for
the Tertiary formation of the Sierra de Guadarrama
(SdG). Their fission track analysis revealed large
amounts of cooling in the period from Pliocene to
present day (see, for example, Fig. 11), in 17 of the
22 analyzed samples. Extra tests were applied by
these authors, using varying assumed initial fission
track lengths. Results of these tests show that, at
least for cooling phases starting from within the
Partial Annealing Zone, the Pliocene cooling is not
an artifact resulting from the applied method [45].
Instead, De Bruijne and Andriessen [27] propose
two tectonic scenarios that might explain this cooling event: (1) active uplift and denudation occurring
in the Pliocene, or (2) the delayed erosion of a
previously uplifted mountain range. Agreement
exists about a neo-tectonic episode starting at the
Middle Miocene, related to the convergence between Africa and Iberia, as derived by [30] and
confirmed by fission track data [14,27]. Furthermore, a change in drainage pattern of the Madrid
408
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 11. Temperature – time curves derived from the fission track analysis, for samples SCS19, SCS11, SCS18 and SCS12 [1]. On the left: The
best fitting thermal history is depicted as a solid black line, the grey band represents the 100-best-fit envelope. The PAZ is the zone between the
dashed lines. On the right: The modeled (solid line) and measured (dashed line) track length distribution. h = height of sampling, MTL = mean
track length, r = uncertainty range in mean track length.
Basin has occurred from the beginning of the Late
Miocene, when the closed basin [29] started evolving to the present-day exoreic drainage system,
inducing a change in base level. Considering this,
one could argue that the Pliocene cooling might be
related to an uplift phase in the Middle Miocene,
creating a mountain range that is eroded during the
Pliocene due to this change of base level.
Nevertheless, De Bruijne and Andriessen [27]
consider scenario (1) as the most plausible, based on
the following reasoning: (a) There is no evidence for
any crustal root to support an elevated range of >3
km, (b) Central Spain is in regional isostatic equilibrium [46], and (c) from Middle Miocene to present,
rock uplift occurred along tectonic units parallel to the
Betic Cordillera that is presently overriding the Iberian Massif [47].
Previous studies assume that tectonic activity may
have ceased in the Pliocene and Quaternary [30,32,
44], based on the lack of seismic activity in the last
decades, and the onlap of Pliocene alluvium far onto
the northern tip of the SCS. However, it is especially
in the northern tip of the SdG where samples do not
reveal the youngest cooling event [27]. Furthermore,
there is no scientific justification to extrapolate the
apparent aseismicity of a few decades over the entire
Pliocene and Quaternary.
From these arguments, De Bruijne and Andriessen
[27] suggest that the youngest denudation event in the
Sierra de Guadarrama was related to active tectonism
as far field effects of the Betic plate boundary tectonTable 3
Input compression rates (vx) per fault, for modeling of mid-Miocene
to present evolution of the southernmost part of the Sierra de
Guadarrama
Fault no.
Period of activation
(Ma)
Compression rate
(mm/year)
Scenario simulating Miocene compression followed by Pliocene
denudation
1
–
–
2
16 – 5
0.195
3
16 – 5
0.201
4
16 – 5
0.037
5
16 – 5
0.259
Scenario providing the best fit
1
–
2
16 – 5
5–0
3
16 – 3
3–0
4
16 – 5
5–0
5
16 – 6
6–0
Fault numbering indicated in Fig. 12.
–
0.04
0.34
0.024
0.633
0.004
0.072
0.05
0.39
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
ics rather than to a change in drainage system,
although the latter might have contributed to this
denudation event as well. In this paragraph we will
use our numerical model in order to test whether these
two scenarios can be distinguished on the base of the
thermal response of the rock samples.
4.2. Model input
Based on seismic profiles through the SCS [30,32,
48], the intracrustal detachment level is chosen to be
at a depth of 12 km. Fig. 10B is used to constrain the
fault dips at surface, the spacing between the faults,
and the present-day topography. Based on present-day
measurements by Fernandez et al. [43], we assume
that the steady state geotherm has a surface tempera-
409
ture of 10 jC and a surface gradient of 28 jC/km. In
the model, this is established as a start condition, by
choosing a surface temperature of 10 jC, a temperature of 592 jC at a depth of 50 km, a thermal
diffusivity of 10 6 m/s2, and a heat production of
4.8 AW/m3 in the upper 12 km. Since the Tertiary
sediments that are deposited in the Madrid Basin are
eroded from the heat-producing crust (i.e. the granites
and gneisses of the Hercynian basement), we also
assume heat production in the sediments.
4.3. Thermal constraints
De Bruijne and Andriessen [14] analyzed 18
basement samples and 4 sediment samples of Mesozoic and Tertiary age from the Sierra de Guadarrama.
Fig. 12. Simulation of the mid-Miocene to present development of the most southeastern part of the Sierra de Guadarrama. (A) Assumed
configuration before mid-Miocene to present deformation, (B) Modeled crustal configuration at present. All the material above the ‘surface line’
is supposed to have been removed by erosion. Numbering of the faults refers to Table 3.
410
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
Fig. 13. Modeled T – t curves for two simulated scenarios to explain Pliocene cooling, with different periods and rates for the youngest phase of
tectonic uplift (see Table 3). Total amount of uplift is equal. For both cases, the denudation is assumed to occur in the Pliocene (5 Ma – present).
Long dashes: Simulation with the youngest phase of deformation occurring from at 16 – 5 Ma. Short dashes: Simulation resulting in the best fit
between modeled and FT-derived T – t curves. Light dashed Lines are results from the FT analysis, within their 100-best-fit envelopes. Thin
dashed lines indicate the PAZ.
From the fission track age and length distributions,
the thermal history of these samples were modeled
according to the method described for Durango apatite by Laslett et al. [49], using the Monte Trax
program of Gallagher [50]. For a detailed discussion
about the fission track method and its limitations, the
reader is referred to [51,52].
Details of the analysis and conclusions about the
regional tectonic history of the area are given by De
Bruijne and Andriessen [14]. Thermal histories of
samples SCS19, SCS11, SCS18 and SCS12 are used
as major constraints for the modeling in this paper
(see Fig. 11). The samples were taken in the tectonic
units crossed by the profile line, and projected on it
along strike of the faults separating the units. The
synthetic rock samples in which temperature is
monitored during time in the model are chosen in
such a way that at the end of the modeling (at 0 Ma)
they have the same positions as the present sites of
samples SCS19, SCS11, SCS18 and SCS12. In
addition, the start position of SCS12 is constrained
by its sampling position, 200 m below the Upper
Cretaceous layer.
4.4. Modeling results
We used our model to simulate the development of
the Sierra de Guadarrama, applying various scenarios
for the last 16 My. Results are shown from the two
most relevant scenarios for this study: In scenario A,
the last episode of uplift occurred with constant
shortening rates from 16 to 5 Ma, followed by a
period of erosion of the resulting topography. In
scenario B, the same amount of shortening was
obtained, now from the horizontal rates of fault-block
movements given in Table 3. These were the values
resulting in the best fit between simulated and fission
track derived T– t curves. Denudation was applied
from 5 Ma to recent in both cases.
The crustal configuration before and after the
modeled period is depicted in Fig. 12. Development
of the area in the period before the mid-Miocene
falls beyond the scope of this paper, and is discussed in detail elsewhere [34]. Fig. 13 shows the
resulting T – t curves for both modeled scenarios. As
could be expected from the synthetic modeling, the
cooling in scenario A starts already in the Miocene,
at the onset of the compressional deformation. We
found that, in this case, all the samples reach
temperatures below the PAZ before the onset of
the Pliocene. From Table 3, it appears that, in order
to explain the observed accelerated cooling, the
major amount of active compressional deformation
must have taken place during the Pliocene, although
some differential movement between the present-day
SdG and the Madrid Basin during the mid- and late
Miocene is necessary as well.
4.5. Discussion
The numerical modeling results clearly show that
uplift occurring during the Pliocene is necessary to
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
explain cooling of the samples from within the
partial annealing zone during this period. Nevertheless, the compression rates given in Table 3 are by
no means meant to represent real exact values. Not
only uncertainties in the model input but particularly
problems in the interpretation of fission track data
force us to consider the results as approximates.
Aside from their uncertainty ranges, fission track
data derived temperature – time curves are nonunique modeling results themselves, and may vary
dependent on the chemistry of the rock sample and
the choice of the annealing model. Progression on
this topic should therefore not be searched in the
refinement of the simulation models, but rather in the
accuracy of the fission track analysis [52 –55].
5. Conclusions and implications
We developed a two-dimensional numerical model
for the thermal consequences of crustal deformation
along compressional faults, and applied it to study the
thermal response on uplift and erosion in an intraplate
tectonic setting. Synthetic rock samples were included
in which the temperature was monitored during the
modeled time-span, in order to be able to compare the
modeling results to temperature –time curves obtained
from thermochronological methods. We focused specifically on the difference in T – t curves between
scenarios of simultaneous uplift and erosion, and
scenarios in which the uplift preceded the erosional
phase. Based on our modeling results, we are able to
draw the following conclusions:
(1) The effects of heat advection, heat production,
lateral heat flow and non-simultaneous uplift and
erosion should be taken into account when
unravelling the uplift history of young, tectonically active mountain belts on the basis of
thermochronological data.
(2) Decreasing temperatures do not necessarily indicate the occurrence of denudation. For fault
dimensions comparable to the border fault of the
Sierra de Guadarrama, lateral movement and uplift
in the absence of erosion can cause more than 57%
of the total amount of cooling, depending on the
total amount of uplift and the distance between the
analyzed rock sample and the fault. This is
411
important in the light of the discussion about the
mutual interaction between uplift, erosion and
climate change [1– 4]: Is enhanced erosion the
primary cause of mountain uplift or is mountain
uplift the primary cause of enhanced erosion? If we
want to use thermochronological data to contribute
to this debate, we should be able to distinguish
between the thermal response for these two
scenarios.
(3) Our results for the Sierra de Guadarrama indicate
that, to a certain degree, active compressional
deformation combined with denudation can
indeed be distinguished from active compressional deformation followed by denudation. We
found that the only scenarios resulting in Pliocene
cooling from the partial annealing zone are those
incorporating a major phase of active compressive deformation during the Pliocene. In addition,
some deformation during the Middle and Late
Miocene must have occurred. This implies that
the Betic compression is still going on today,
which is consistent with the plate tectonic setting
of continuing NW – SE oriented convergence
between the European and African plate [56].
Acknowledgements
Bernd Andeweg and Giovanni Bertotti are thanked
for help, comments and discussions on an earlier
version of the manuscript. This paper benefited greatly
from reviews by D. Waltham and an anonymous
reviewer. We acknowledge the editorial efforts of Prof.
Dr. K. Farley. Financial support to MtV and CdB was
provided by the Netherlands Foundation for Scientific
Research (NWO/ALW). This is contribution No.
2004.05.05 of the Netherlands School of Sedimentary
Geology. [KF]
References
[1] P. Molnar, P. England, Late Cenozoic uplift of mountain
ranges and global climate change: chicken or egg? Nature
346 (1990) 29 – 34.
[2] D.W. Burbank, Causes of recent Himalayan uplift deduced
from deposited patterns in the Ganges basin, Nature 357
(1992) 680 – 683.
[3] J.P. Avouac, E.B. Burov, Erosion as a driving mechanism of
412
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
intracontinental mountain growth, J. Geophys. Res. 101 (B8)
(1996) 17747 – 17769.
S.D. Willett, Orogeny and orography: the effects of erosion on
the structure of mountain belts, J. Geophys. Res. 104 (B12)
(1999) 28957 – 28981.
M.A. House, B.P. Wernicke, K.A. Farley, Dating topography
of the Sierra Nevada, California, using apatite (U – Th)/He
ages, Nature 396 (1998) 66 – 69.
P.G. Fitzgerald, J.A. Muñoz, P.J. Coney, S.L. Baldwin, Asymmetric exhumation across the Pyrenean orogen: implications
for the tectonic evolution of a collissional orogen, Earth Planet. Sci. Lett. 173 (1999) 157 – 170.
J. Juez-Larré, P.A.M. Andriessen, Post Late Paleozoic tectonism in the southern Catalan Coastal Ranges (NE Spain),
assessed by apatite fission track analysis, Tectonophysics
349 (2002) 113 – 129.
T.A. Ehlers, K.A. Farley, Apatite (U – Th)/He thermochronometry: methods and applications to problems in tectonic and
surface processes, Earth Planet. Sci. Lett. 206 2003, pp. 1 – 14.
G. Wagner, P. Van den Haute, Fission-Track Dating, Kluwer
Academic Publishing, Dordrecht, 1992, p. 285.
P. Andriessen, Fission-track analysis: principles, methodology
and implications for tectono-thermal histories of sedimentary
basins, orogenic belts and continental margins, Geol. Mijnb.
74 (1995) 1 – 12.
K. Gallagher, R. Brown, J. Christopher, Fission-track analysis
and its applications to geological problems, Annu. Rev. Earth
Planet. Sci. 26 (1998) 519 – 572.
A.J.W. Gleadow, R.W. Brown, Fission track thermochronology and the long-term denudational response to tectonics, in:
M.A. Summerfield (Ed.), Geomorphology and Global tectonics, Wiley, Chichester, 2000, pp. 57 – 75.
A.J. Hurford, Uplift and cooling pathways derived from fission track analysis and mica dating: a review, Geol. Rundsch.
80 (1991) 349 – 368.
C.H. De Bruijne, P.A.M. Andriessen, Interplay of intraplate
tectonics and surface processes in the Sierra de Guadarrama
(central Spain) assessed by apatite fission track analysis, Phys.
Chem. Earth 25 (2000) 555 – 563.
K. Stüwe, L. White, R. Brown, The influence of eroding
topography on steady state isotherms. Application to fission
track analysis, Earth Planet. Sci. Lett. 124 (1994) 63 – 74.
N.S. Mancktelow, B. Grasemann, Time dependent affects of
heat advection and topography on cooling histories during
erosion, Tectonophysics 270 (1997) 167 – 195.
K. Stüwe, M. Hintermüller, Topography and isotherms revisited: the influence of laterally migrating drainage divides,
Earth Planet. Sci. Lett. 184 (2000) 287 – 303.
M.A. Moore, P.C. England, On the inference of denudation
rates from cooling ages of minerals, Earth Planet. Sci. Lett.
185 (2001) 265 – 284.
R.A. Wolf, K.A. Farley, D.M. Kass, Modeling of the temperature sensitivity of the apatite (U – Th)/He thermochronometer,
Chem. Geol. 148 (1998) 105 – 114.
K.A. Farley, Helium diffusion from apatite: general behavior
as illustrated by Durango fluorapatite, J. Geophys. Res. 105
(B2) (2000) 2903 – 2914.
[21] A. Meesters, T. Dunai, Solving the production – diffusion
equation for finite diffusion domains of the various shapes:
Part 1. Implications for low temperature (U – Th)/He thermochronology, Chem. Geol. 186 (3 – 4) (2002) 333 – 344.
[22] A. Meesters, T. Dunai, Solving the production – diffusion
equation for finite diffusion domains of various shapes: Part
2. Application to cases with Alpha ejection and non-homogeneous distribution of the source, Chem. Geol. 186 (3 – 4)
(2002) 345 – 363.
[23] J. Braun, Quantifying the effect of recent relief changes on
age – elevation relationships, Earth Planet. Sci. Lett. 200
(2002) 331 – 343.
[24] M. ter Voorde, G. Bertotti, Thermal effects of normal faulting
during rifted basin formation: 1. A finite difference model,
Tectonophysics 240 (1994) 133 – 144.
[25] B. Grasemann, N.S. Mancktelow, Two-dimensional thermal
modeling of normal faulting: the Simplon Fault Zone, Central
Alps, Switzerland, Tectonophysics 225 (1993) 155 – 165.
[26] T.A. Ehlers, P.A. Armstrong, D.S. Chapman, Normal fault thermal regimes and the interpretation of low-temperature thermochronometers, Phys. Earth Planet. Inter. 126 (2001) 179 – 194.
[27] C.H. De Bruijne, P.A.M. Andriessen, Far field effects of the
Alpine plate tectonics in the Iberian microplate recorded by
fault related denudation in the Spanish Central System (Central Spain), Tectonophysics 349 (2002) 161 – 184.
[28] J.P. Calvo, et al, Up-to-date Spanish continental Neogene and
paleocimatic interpretation, Rev. Soc. Geol. Esp. 6 (1993)
29 – 40.
[29] J.P. Calvo, B.F. Jones, M. Bustillo, R. Fort, A.M. Alonso
Zarza, C. Kendall, Sedimentology and geochemistry of carbonates from lacustrine sequences in the Madrid basin,
central Spain, Chem. Geol. 123 (1995) 173 – 191.
[30] G. De Vicente, J.L. Giner, A. Munoz-Martin, J.M. GonzalezCasado, R. Lindo, Determination of present-day stress tensor
and neotectonic interval in the Spanish Central System and
Madrid Basin, central Spain, Tectonophysics 266 (1996)
405 – 424.
[31] G. De Vicente, J.M. Gonzalez-Casado, A. Munoz-Martin, J.
Giner, M.A. Rodriguez-Pascau, Structure and tertiary evolution of the Madrid basin, in: P.F. Friend, C.J. Dabrio (Eds.),
Tertiary Basins in the Iberian Peninsula, Cambridge University Press, 1996, pp. 250 – 259.
[32] B. Andeweg, G. De Vicente, S.A.P.L. Cloetingh, J. Giner, A.
Munoz-Martin, Local stress fields and intraplate deformation
of Iberia: variations in spatial and temporal interplay of regional stress sources, Tectonophysics 305 (1999) 153 – 164.
[33] B. Andeweg, Cenozoic tectonic evolution of the Iberian Peninsula, effects and causes of changing stress fields, Published
PhD thesis, Vrije Universiteit Amsterdam, the Netherlands,
2002, 178 pp.
[34] C.H. De Bruijne, B. Andeweg, W. Nijman, M. ter Voorde,
Paleogene tectonic activity of the Spanish Central System,
evidences from structural and sedimentary geology, apatite
fission tracks, and numerical modelling, Basin Research, submitted for publication.
[35] C.H. De Bruijne, Denudation, intraplate tectonics and far field
effects, an integrated apatite fission track study in Central
M. ter Voorde et al. / Earth and Planetary Science Letters 223 (2004) 395–413
[36]
[37]
[38]
[39]
[40]
[41]
[42]
[43]
[44]
[45]
[46]
[47]
Spain, Published PhD thesis, Vrije Universiteit Amsterdam,
the Netherlands, 2001, 164 pp.
S. Cloetingh, E. Burov, F. Beekman, B. Andeweg, P. Andriessen, D. Garcia-Castellanos, G. de Vicente, R. Vegas, Lithospheric folding in Iberia, Tectonics 21 (5) (2002) 1041 – 1066.
M. ter Voorde, S. Cloetingh, Numerical modeling of extension
in faulted crust: effects of localized and regional deformation on
basin stratigraphy, in: P.G. Buchanan, D.A. Nieuwland (Eds.),
Modern developments in structural interpretation, validating
and modeling, Spec. Publ.-Geol. Soc. 99, (1996) 283 – 296.
M. ter Voorde, Tectonic modeling of lithospheric extension
along faults, implications for thermal and mechanical structure
and basin stratigraphy, Published PhD thesis, Vrije Universiteit Amsterdam, the Netherlands, 1996, 197 pp.
C. Jaupart, On the average amount and vertical distribution of
radioactivity in the continental crust, in: J. Burrus (Ed.), Thermal Modeling in Sedimentary Basins, IFP Research Conferences on Exploration,Technip, Paris, 1986, pp. 33 – 47.
J.C. De Bremaecker, Temperature, subsidence and hydrocarbon maturation in extensional basins: a finite element model,
Am. Assoc. Pet. Geol. Bull. 67 (1983) 1410 – 1414.
J. Burrus, F. Audebert, Thermal and compaction processes in a
young rifted basin containing evaporites: Gulf of Lions,
France, Am. Assoc. Pet. Geol. Bull. 74 (1990) 1420 – 1440.
J. Brewer, Thermal effects of thrust faulting, Earth Planet. Sci.
Lett. 56 (1981) 233 – 244.
M. Fernandez, I. Marzan, A. Correia, E. Ramalho, Heat flow,
heat production, and lithospheric thermal regime in the Iberian
Peninsula, Tectonophysics 291 (1998) 29 – 53.
R. Vegas, J.T. Vazquez, E. Surinach, A. Marcos, Model of
distributed deformation, block rotation and crustal thickening
for the formation of the Spanish Central System, Tectonophysics 184 (1990) 367 – 378.
G.M. Laslett, R. Galbraith, Statistical modeling of thermal
annealing of fission tracks in apatite, Geochim. Cosmochim.
Acta 60 (1996) 5117 – 5131.
G. Stapel, The nature of isostacy in West Iberia, and its bearing
on Mesozoic and Cenozoic regional tectonics, Published PhD
thesis, Vrije Universiteit Amsterdam, the Netherlands, 1999.
J. Morales, I. Serrano, A. Jabaloy, J. Galindo-Zaldivar, D.
Zhao, F. Torcal, F. Vidal, F. Gonzalez-Lodeiro, Active conti-
[48]
[49]
[50]
[51]
[52]
[53]
[54]
[55]
[56]
[57]
[58]
413
nental subduction beneath the Betic Cordillera and the Alboran
Sea, Geology 27 (1999) 735 – 738.
E. Banda, E. Surinach, A. Aparicio, J. Sierra, F. Ruiz de la Parte,
Crust and upper mantle structure of the Central Iberian Meseta
(Spain), Geophys. J. R. Astron. Soc. 67 (1981) 779 – 789.
G.M. Laslett, P.F. Green, I.R. Duddy, A.J.W. Gleadow, Thermal annealing of fission tracks in apatite, 2. A quantitative
analysis, Chem. Geol. 65 (1987) 1 – 13.
K. Gallagher, Evolving temperature histories from apatite fission track data, Earth Planet. Sci. Lett. 136 (1995) 421 – 435.
C.E. Ravenhurst, R.A. Donelick, Fission track thermochronology, in: M. Zentilli, P.H. Reynolds (Eds.), Short Course Handbook on Low Thermochronology, Min. Assoc. of Canada,
Nova Scotia, 1992, pp. 21 – 43.
P.F. Green, I.R. Duddy, K.A. Hegarty, Quantifying exhumation from apatite fission-track analysis and vitrinite reflectance
data: precision, accuracy and latest results from the Atlantic
margin of NW Europe, in: A.G. Doré, J.A. Cartwright, M.S.
Stoker, J.P. Turner, N. White (Eds.), Exhumation of the North
Atlantic Margin: Timing, Mechanisms and Implications for
Petroleum Exploration, Spec. Publ.-Geol. Soc. Lond. 196,
(2002) 331 – 354.
W.D. Carlson, R.A. Donelick, R.A. Ketcham, Variability of
apatite fission-track annealing kinetics: I. Experimental
results, Am. Mineral. 84 (1999) 1213 – 1223.
R.A. Donelick, R.A. Ketcham, W.D. Carlson, Variability of
apatite fission-track annealing kinetics: II. Crystallographic
orientation effects, Am. Mineral. 84 (1999) 1224 – 1234.
R.A. Ketcham, R.A. Donelick, W.D. Carlson, Variability of
apatite fission-track annealing kinetics: III. Extrapolation to
geological timescales, Am. Mineral. 84 (1999) 1235 – 1255.
J. Galindo-Zaldı́var, F. Gonzalez-Lodeiro, A. Jabaloy, Stress
and paleostress in the Betic – Rif cordilleras (Miocene to the
present), Tectonophysics 227 (1993) 105 – 126.
J.D. van Wees, Tectonic modeling of basin deformation and
inversion dynamics, the role of pre-existing faults and continental lithosphere rheology in basin evolution, Published PhD
thesis, Vrije Universiteit Amsterdam, 1994, 164 pp.
R. Querol Muller, Geologia del subsuelo de la Cuenca del Tajo,
Instituto Technologico Geominero de Espana, Madrid, 1989.