SCIENCE@home

Low-latitude arc–continent collision as a driver for global cooling

O. Jagoutz,F. Macdonald,L. Royden

Published 2016 in Proceedings of the National Academy of Sciences of the United States of America

ABSTRACT

Significance This manuscript provides a mechanism for triggering cooling events following the Cretaceous Thermal Maximum and the Early Eocene Climate optimum that ultimately resulted in the Cenozoic glaciation. We present a quantitative model of changes in CO2 sources and sinks during the closure of the Neo-Tethys Ocean. Our results suggest that long-term cooling was predominantly due to obduction of highly weatherable mafic and ultramafic Ca- and Mg-rich rocks (ophiolites) in the wet tropics. Our model accounts for both the two episodes of cooling and also the partial recovery in temperatures between ∼70 and 50 Ma. New constraints on the tectonic evolution of the Neo-Tethys Ocean indicate that at ∼90–70 Ma and at ∼50–40 Ma, vast quantities of mafic and ultramafic rocks were emplaced at low latitude onto continental crust within the tropical humid belt. These emplacement events correspond temporally with, and are potential agents for, the global climatic cooling events that terminated the Cretaceous Thermal Maximum and the Early Eocene Climatic Optimum. We model the temporal effects of CO2 drawdown from the atmosphere due to chemical weathering of these obducted ophiolites, and of CO2 addition to the atmosphere from arc volcanism in the Neo-Tethys, between 100 and 40 Ma. Modeled variations in net CO2-drawdown rates are in excellent agreement with contemporaneous variation of ocean bottom water temperatures over this time interval, indicating that ophiolite emplacement may have played a major role in changing global climate. We demonstrate that both the lithology of the obducted rocks (mafic/ultramafic) and a tropical humid climate with high precipitation rate are needed to produce significant consumption of CO2. Based on these results, we suggest that the low-latitude closure of ocean basins along east–west trending plate boundaries may also have initiated other long-term global cooling events, such as Middle to Late Ordovician cooling and glaciation associated with the closure of the Iapetus Ocean.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-71 of 71 references · Page 1 of 1

CITED BY

Showing 1-100 of 106 citing papers · Page 1 of 2

12
Next