Ramon Mas
Universidad Complutense de Madrid, Stratigrphy, Faculty Member
Research Interests:
The Cameros Basin (North Spain) is a Late Jurassic-Early Cretaceous extensional basin, which was inverted during the Cenozoic. It underwent a remarkable thermal evolution, as indicated by the record of anomalous high temperatures in its... more
The Cameros Basin (North Spain) is a Late Jurassic-Early Cretaceous extensional basin,
which was inverted during the Cenozoic. It underwent a remarkable thermal evolution, as
indicated by the record of anomalous high temperatures in its deposits. In this work the
subsidence and thermal history of the basin is reconstructed, using subsidence analysis and
2D thermal modeling.
The Cameros Basin (North-central Spain) records a remarkable and complex tectonosedimentary
evolution and thermal history, making the study of this basin very useful for the
comprehension of the geodynamic evolution of the of the Iberian Plate area. In the central
Iberian domain the Cameros Basin experienced the highest subsidence (Salas et al., 2001)
with the deposition of up to 6500 m of mainly continental sediments in fewer than 50 My (e.g.
Mas et al., 1993). Furthermore, in the northeastern sectors of the basin, part of the synextensional
succession was affected by very low- to low-grade metamorphism. The origin
and distribution of the anomalously high temperatures recorded have been the subject of
substantial debate over the past three decades. Several inorganic proxies (mineral
paragenesis, illite crystallinity and fluid inclusions) have been used to characterize the
metamorphism. Some authors (Guiraud & Séguret, 1985; Goldberg et al., 1988; Casas-
Sainz, 1992; Mata et al., 2001; Del Río et al., 2009; Casas et al., 2012) have attributed this
metamorphism to burial. However, others (Casquet et al., 1992; Barrenechea et al., 1995;
Mantilla-Figueroa et al., 1998; Alonso-Azcárate et al., 1999; Barrenechea et al., 2001; Ochoa
et al., 2007; González-Acebrón et al., 2011; González-Acebrón et al., 2012) have interpreted
the metamorphism as having a hydrothermal and allochemical origin. The present study is an
attempt to improve the understanding of the thermal evolution of the Cameros Basin. To
determine the thermal stages of the deposits of the basin, for the first time, accurate vitrinite
reflectance (%Ro, VR) measurements were performed, providing information on the real
temperatures reached in the basin infill. There was an anomalous pattern of the vitrinite
reflectance with the depth, compared to typical extensional basins. To improve temperature
history reconstruction, %Ro data were also combined with fluid inclusions data, as the latter
are the only direct evidence of the circulation of palaeofluids (Goldstein & Reynolds, 1994).
The reconstruction of the thermal history of a basin requires knowledge of the paleo-heat
flow and its variation associated with basin formation. In the case of ancient basins, such
data can be obtained through subsidence analysis and estimation of the level of initial and
thermal subsidence. Therefore, in addition to comparative studies of vitrinite reflectance, in
this work the subsidence analysis of the basin was performed.
As the Cameros Basin is an ancient uplifted and partially eroded continental extensional
basin, a number of less common constraints are required (e.g., the amount of material
eroded, the age of syn-extensional sequences, and the initial crust and mantle lithospheric
thicknesses) to model its thermal history. Therefore, the results obtained herein require a
critical interpretation. Despite the numerous uncertainties, this study can considerably
improve the understanding of the complex thermal history of the Cameros Basin by
estimating the heat flow range at the end of the extension phase and comparing the %Ro data with thermal modeling results. Additionally, relevant data for the comprehension of the
geodynamic evolution of the Iberian Plate are provided.
which was inverted during the Cenozoic. It underwent a remarkable thermal evolution, as
indicated by the record of anomalous high temperatures in its deposits. In this work the
subsidence and thermal history of the basin is reconstructed, using subsidence analysis and
2D thermal modeling.
The Cameros Basin (North-central Spain) records a remarkable and complex tectonosedimentary
evolution and thermal history, making the study of this basin very useful for the
comprehension of the geodynamic evolution of the of the Iberian Plate area. In the central
Iberian domain the Cameros Basin experienced the highest subsidence (Salas et al., 2001)
with the deposition of up to 6500 m of mainly continental sediments in fewer than 50 My (e.g.
Mas et al., 1993). Furthermore, in the northeastern sectors of the basin, part of the synextensional
succession was affected by very low- to low-grade metamorphism. The origin
and distribution of the anomalously high temperatures recorded have been the subject of
substantial debate over the past three decades. Several inorganic proxies (mineral
paragenesis, illite crystallinity and fluid inclusions) have been used to characterize the
metamorphism. Some authors (Guiraud & Séguret, 1985; Goldberg et al., 1988; Casas-
Sainz, 1992; Mata et al., 2001; Del Río et al., 2009; Casas et al., 2012) have attributed this
metamorphism to burial. However, others (Casquet et al., 1992; Barrenechea et al., 1995;
Mantilla-Figueroa et al., 1998; Alonso-Azcárate et al., 1999; Barrenechea et al., 2001; Ochoa
et al., 2007; González-Acebrón et al., 2011; González-Acebrón et al., 2012) have interpreted
the metamorphism as having a hydrothermal and allochemical origin. The present study is an
attempt to improve the understanding of the thermal evolution of the Cameros Basin. To
determine the thermal stages of the deposits of the basin, for the first time, accurate vitrinite
reflectance (%Ro, VR) measurements were performed, providing information on the real
temperatures reached in the basin infill. There was an anomalous pattern of the vitrinite
reflectance with the depth, compared to typical extensional basins. To improve temperature
history reconstruction, %Ro data were also combined with fluid inclusions data, as the latter
are the only direct evidence of the circulation of palaeofluids (Goldstein & Reynolds, 1994).
The reconstruction of the thermal history of a basin requires knowledge of the paleo-heat
flow and its variation associated with basin formation. In the case of ancient basins, such
data can be obtained through subsidence analysis and estimation of the level of initial and
thermal subsidence. Therefore, in addition to comparative studies of vitrinite reflectance, in
this work the subsidence analysis of the basin was performed.
As the Cameros Basin is an ancient uplifted and partially eroded continental extensional
basin, a number of less common constraints are required (e.g., the amount of material
eroded, the age of syn-extensional sequences, and the initial crust and mantle lithospheric
thicknesses) to model its thermal history. Therefore, the results obtained herein require a
critical interpretation. Despite the numerous uncertainties, this study can considerably
improve the understanding of the complex thermal history of the Cameros Basin by
estimating the heat flow range at the end of the extension phase and comparing the %Ro data with thermal modeling results. Additionally, relevant data for the comprehension of the
geodynamic evolution of the Iberian Plate are provided.
Research Interests:
The Mesozoic Iberian basin developed inside the Iberian plate in the eastern end of the Tethys sea. As a result of the Tertiary convergence between the Iberian plate with the European and African plates, the Iberian basin was... more
The Mesozoic Iberian basin developed inside the Iberian plate in the eastern end of the Tethys
sea. As a result of the Tertiary convergence between the Iberian plate with the European and
African plates, the Iberian basin was contractionally inverted, giving rise to the Iberian and
Catalan Coastal chains and the surrounding Tertiary basins. The Bouguer anomaly map of the
area shows that the Iberian Chain has crusta I roots which would have produced during the
Tertiary contractional period.
sea. As a result of the Tertiary convergence between the Iberian plate with the European and
African plates, the Iberian basin was contractionally inverted, giving rise to the Iberian and
Catalan Coastal chains and the surrounding Tertiary basins. The Bouguer anomaly map of the
area shows that the Iberian Chain has crusta I roots which would have produced during the
Tertiary contractional period.