decrease in the pCO 2 . This decline in pCO 2 is further reinforced by the increased transport of organic carbon and its
burial in sedimentary basins at the foot of the reliefs (Goddéris et al. 2017). The threshold for freezing is defined by the
level of atmospheric CO 2 concentration below which
freezing occurs. This threshold was reduced during the
Carboniferous because of the slow, inexorable increase in
insolation produced by the Sun. Estimates, based on the
analysis of fossil leaves and pedogenic carbonates, found
that in basins at low latitudes pCO 2 fluctuated periodically
from about 200 to 300 ppmv during the Upper Carboniferous with a minimum concentration of 160–300 ppmv
(Montañez et al. 2016). The periodicity of these fluctuations
seems to be dominated by an eccentricity signal of 405 ka.
The vegetation cover of these equatorial basins also varies
between dry vegetation during interglacials and humid
tropical vegetation during interglacials (Montañez et al.
2016) which influence the organic carbon cycle, possibly
causing fluctuations in the volume of continental ice on
Gondwana and is superimposed on the long-term trend driven by geodynamics.
Conclusion
The impact of paleogeographic changes on climate and its
evolution is fundamental. The presence of a supercontinent
produces climates characterized by strong contrasts (continental climate at high latitudes, wide arid zone in the subtropics, as in the Permian), while a fragmented continent,
combined with vast shelf seas produced as a consequence of a
high sea level, as in the early Upper Cretaceous, will be
conducive to a climate with relatively low contrasts. The
dispersion of landmasses therefore represents an important
climate forcing, which does not, however, offer a complete
explanation for the climate history of the Earth. Orogenesis is
another major forcing of the climate at geological timescales.
It is therefore essential to delineate the spatio-temporal evolution of all the orogens as accurately as possible (Fig. 22.5),
even if the reconstructed paleoaltitudes remain, for the time
being, subject to considerable uncertainty. While the impact
of paleogeography on atmospheric circulation has been
widely studied through numerical modeling, the impact of
paleogeographic changes on ocean circulation is far from
well understood. Studies have quantified the impact of the
opening of seaways (Panama or Indonesian) or large-scale
ocean connections (South Atlantic—Central Atlantic) on the
climate through the redistribution of heat carried by ocean
currents. The chronology of the openings and closures of the
ocean passages, in addition to that of the orogens, is thus
essential to a good understanding of the climate system at the
scale of geological time. In this framework, the development
of new isotopic tools, the improvements of traditional proxies
calibration and the rise of paleoclimate modelling should
allow a better quantification of the links between paleogeography and climate in the next decades.
References
Bacon, C. D., Silvestro, D., Jaramillo, C., Smith, B. T., Chakrabarty, P.,
& Antonelli, A. (2015). Biological evidence supports an early and
complex emergence of the Isthmus of Panama. Proceedings of the
National Academy of Sciences, 112, 6110–6115.
Bahr, A., Kolber, G., Kaboth-Bahr, S., Reinhardt, L., Friedrich, O.,
Pross, J. (2020). Mega-monsoon variability during the late Triassic:
Re-assessing the role of orbital forcing in the deposition of playa
sediments in the Germanic Basin. Sedimentology, 67, 951–970.
https://doi.org/10.1111/sed.12668.
Berner, R. A. (2001). GEOCARB III: A revised model of atmospheric
CO 2 over Phanerozoic time. American Journal of Science, 301(2),
182–204. https://doi.org/10.2475/ajs.301.2.182.
Biggin, A. J., de Wit, M. J., Langereis, C. G., Zegers, T. E.,Voûte, S.,
Dekkers, M. J., & Drost, K. (2011). Palaeomagnetism of Archaean
rocks of the Onverwacht Group, Barberton Greenstone Belt (southern
Africa): Evidence for a stable and potentially reversing geomagnetic
field at ca. 3.5 Ga. Earth and Planetary Science Letters, 302, 314–328.
Bolin, B. (1950). On the influence of the Earth’s orography on the
general character of the westerlies. Tellus, 2(3). http://www.tellusa.
net/index.php/tellusa/article/download/8547/9993.
Bond, D. P. G., Hilton, J., Wignall, P. B., Ali, J. R., Stevens, L. G.,
Sun, Y., and Lai, X. (2010). The Middle Permian (Capitanian) mass
extinction on land and in the oceans. Earth-Science Reviews, 102,
100–116, https://doi.org/10.1016/j.earscirev.2010.07.004.
Bond, D. P. G. & Wignall, P. B. (2014). Large igneous provinces and
mass extinctions: An update. In G. Keller, & A. C. Kerr (Eds.),
Volcanism, impacts, and mass extinctions: Causes and effects:
Geological society of America special paper, 505 (p. 29). https://
doi.org/10.1130/2014.2505(02).
Bonifacie, M., et al. (2017). Calibration of the dolomite clumped
isotope thermometer from 25 to 350 °C, and implications for a
universal calibration for all (Ca, Mg, Fe) CO3 carbonates.
Geochimica et Cosmochimica Acta, 200(1), 255–279.
Bonnefille, R. (2010). Cenozoic vegetation, climate changes and hominid
evolution in tropical Africa. Global and Planetary Change, 72, 390–411.
Boos, W. R. (2015). A review of recent progress on Tibet’s role in the
South Asian monsoon. CLIVAR Exchanges, 19(23), 27.
Bornemann, A., Norris, R. D., Friedrich, O., Beckmann, B., Schouten,
S., et al. (2008). Isotopic evidence for glaciation during the
Cretaceous supergreenhouse. Science, 319, 189–192.
Brierley, C. M., & Fedorov, A. V. (2016). Comparing the impacts of
Miocene–Pliocene changes in Inter-Ocean gateways on climate:
Central American Seaway, Bering Strait, and Indonesia. Earth and
Planetary Science Letters, 444(juin), 116–130. https://doi.org/10.
1016/j.epsl.2016.03.010.
Broccoli, A. J., & Manabe, S. (1992). The effects of orography on
Mid-latitude Northern Hemisphere Dry Climates. Journal of Climate,
5(11), 1181–1201. https://doi.org/10.1175/1520-0442(1992)005.
Cane, M. A., & Molnar, P. (2001). Closing of the Indonesian Seaway
as a Precursor to East African aridification around 3–4 million years
ago. Nature, 411, 157–162.
Caquineau, T., Paquette, J.-L., & Philippot, P. (2018). U-Pb detrital
zircon geochronology of the Turee Creek Group, Hamersley Basin,
Western Australia: Timing and correlation of the Paleoproterozoic
glaciations. Precambrian Research, 307, 34–50. https://doi.org/10.
1016/j.precamres.2018.01.003.
266
F. Fluteau and P. Sepulchre
burial in sedimentary basins at the foot of the reliefs (Goddéris et al. 2017). The threshold for freezing is defined by the
level of atmospheric CO 2 concentration below which
freezing occurs. This threshold was reduced during the
Carboniferous because of the slow, inexorable increase in
insolation produced by the Sun. Estimates, based on the
analysis of fossil leaves and pedogenic carbonates, found
that in basins at low latitudes pCO 2 fluctuated periodically
from about 200 to 300 ppmv during the Upper Carboniferous with a minimum concentration of 160–300 ppmv
(Montañez et al. 2016). The periodicity of these fluctuations
seems to be dominated by an eccentricity signal of 405 ka.
The vegetation cover of these equatorial basins also varies
between dry vegetation during interglacials and humid
tropical vegetation during interglacials (Montañez et al.
2016) which influence the organic carbon cycle, possibly
causing fluctuations in the volume of continental ice on
Gondwana and is superimposed on the long-term trend driven by geodynamics.
Conclusion
The impact of paleogeographic changes on climate and its
evolution is fundamental. The presence of a supercontinent
produces climates characterized by strong contrasts (continental climate at high latitudes, wide arid zone in the subtropics, as in the Permian), while a fragmented continent,
combined with vast shelf seas produced as a consequence of a
high sea level, as in the early Upper Cretaceous, will be
conducive to a climate with relatively low contrasts. The
dispersion of landmasses therefore represents an important
climate forcing, which does not, however, offer a complete
explanation for the climate history of the Earth. Orogenesis is
another major forcing of the climate at geological timescales.
It is therefore essential to delineate the spatio-temporal evolution of all the orogens as accurately as possible (Fig. 22.5),
even if the reconstructed paleoaltitudes remain, for the time
being, subject to considerable uncertainty. While the impact
of paleogeography on atmospheric circulation has been
widely studied through numerical modeling, the impact of
paleogeographic changes on ocean circulation is far from
well understood. Studies have quantified the impact of the
opening of seaways (Panama or Indonesian) or large-scale
ocean connections (South Atlantic—Central Atlantic) on the
climate through the redistribution of heat carried by ocean
currents. The chronology of the openings and closures of the
ocean passages, in addition to that of the orogens, is thus
essential to a good understanding of the climate system at the
scale of geological time. In this framework, the development
of new isotopic tools, the improvements of traditional proxies
calibration and the rise of paleoclimate modelling should
allow a better quantification of the links between paleogeography and climate in the next decades.
References
Bacon, C. D., Silvestro, D., Jaramillo, C., Smith, B. T., Chakrabarty, P.,
& Antonelli, A. (2015). Biological evidence supports an early and
complex emergence of the Isthmus of Panama. Proceedings of the
National Academy of Sciences, 112, 6110–6115.
Bahr, A., Kolber, G., Kaboth-Bahr, S., Reinhardt, L., Friedrich, O.,
Pross, J. (2020). Mega-monsoon variability during the late Triassic:
Re-assessing the role of orbital forcing in the deposition of playa
sediments in the Germanic Basin. Sedimentology, 67, 951–970.
https://doi.org/10.1111/sed.12668.
Berner, R. A. (2001). GEOCARB III: A revised model of atmospheric
CO 2 over Phanerozoic time. American Journal of Science, 301(2),
182–204. https://doi.org/10.2475/ajs.301.2.182.
Biggin, A. J., de Wit, M. J., Langereis, C. G., Zegers, T. E.,Voûte, S.,
Dekkers, M. J., & Drost, K. (2011). Palaeomagnetism of Archaean
rocks of the Onverwacht Group, Barberton Greenstone Belt (southern
Africa): Evidence for a stable and potentially reversing geomagnetic
field at ca. 3.5 Ga. Earth and Planetary Science Letters, 302, 314–328.
Bolin, B. (1950). On the influence of the Earth’s orography on the
general character of the westerlies. Tellus, 2(3). http://www.tellusa.
net/index.php/tellusa/article/download/8547/9993.
Bond, D. P. G., Hilton, J., Wignall, P. B., Ali, J. R., Stevens, L. G.,
Sun, Y., and Lai, X. (2010). The Middle Permian (Capitanian) mass
extinction on land and in the oceans. Earth-Science Reviews, 102,
100–116, https://doi.org/10.1016/j.earscirev.2010.07.004.
Bond, D. P. G. & Wignall, P. B. (2014). Large igneous provinces and
mass extinctions: An update. In G. Keller, & A. C. Kerr (Eds.),
Volcanism, impacts, and mass extinctions: Causes and effects:
Geological society of America special paper, 505 (p. 29). https://
doi.org/10.1130/2014.2505(02).
Bonifacie, M., et al. (2017). Calibration of the dolomite clumped
isotope thermometer from 25 to 350 °C, and implications for a
universal calibration for all (Ca, Mg, Fe) CO3 carbonates.
Geochimica et Cosmochimica Acta, 200(1), 255–279.
Bonnefille, R. (2010). Cenozoic vegetation, climate changes and hominid
evolution in tropical Africa. Global and Planetary Change, 72, 390–411.
Boos, W. R. (2015). A review of recent progress on Tibet’s role in the
South Asian monsoon. CLIVAR Exchanges, 19(23), 27.
Bornemann, A., Norris, R. D., Friedrich, O., Beckmann, B., Schouten,
S., et al. (2008). Isotopic evidence for glaciation during the
Cretaceous supergreenhouse. Science, 319, 189–192.
Brierley, C. M., & Fedorov, A. V. (2016). Comparing the impacts of
Miocene–Pliocene changes in Inter-Ocean gateways on climate:
Central American Seaway, Bering Strait, and Indonesia. Earth and
Planetary Science Letters, 444(juin), 116–130. https://doi.org/10.
1016/j.epsl.2016.03.010.
Broccoli, A. J., & Manabe, S. (1992). The effects of orography on
Mid-latitude Northern Hemisphere Dry Climates. Journal of Climate,
5(11), 1181–1201. https://doi.org/10.1175/1520-0442(1992)005.
Cane, M. A., & Molnar, P. (2001). Closing of the Indonesian Seaway
as a Precursor to East African aridification around 3–4 million years
ago. Nature, 411, 157–162.
Caquineau, T., Paquette, J.-L., & Philippot, P. (2018). U-Pb detrital
zircon geochronology of the Turee Creek Group, Hamersley Basin,
Western Australia: Timing and correlation of the Paleoproterozoic
glaciations. Precambrian Research, 307, 34–50. https://doi.org/10.
1016/j.precamres.2018.01.003.
266
F. Fluteau and P. Sepulchre