Abstract
The devolatilization of calcium sulfate, which is present in the target rock of the Chicxulub, Mexico impact structure, and dispersal in the stratosphere of the resultant sulfuric acid aerosol have been suggested as a possible mechanism for the Cretaceous-Tertiary extinctions [1,2]. We measured the amount of SO2 produced from two shock-induced devolatilization reactions of calcium sulfate up to 42 GPa in the laboratory: CaSO4+SiO2→CaSiO3+SO3↑CaSO4→CaO+SO2↑+ 1 2O2↑. We found both to proceed to a much lower extent than calculated by equilibrium thermodynamic calculations. Reaction products are found to be ∼ 10-2 times those calculated for equilibrium. Upon modeling the quantity of sulfur oxides degassed into the atmosphere from shock devolatilization of CaSO4 in the Chicxulub lithographic section, the resulting 9 × 1016 to 6 × 1017 g (in sulfur mass) is lower by a factor of 10-100 than previous upper limit estimates, the related environmental stress arising from the resultant global cooling and fallout of acid rain is insufficient to explain the widespread K-T extinctions.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 615-628 |
| Number of pages | 14 |
| Journal | Earth and Planetary Science Letters |
| Volume | 128 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - 1994 |
Fingerprint
ASJC Scopus subject areas
- Earth and Planetary Sciences (miscellaneous)
- Geochemistry and Petrology
- Geophysics
- Earth and Planetary Sciences(all)
- Environmental Science(all)
Cite this
Shock-induced devolatilization of calcium sulfate and implications for K-T extinctions. / Chen, Guangqing; Tyburczy, James; Ahrens, Thomas J.
In: Earth and Planetary Science Letters, Vol. 128, No. 3-4, 1994, p. 615-628.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Shock-induced devolatilization of calcium sulfate and implications for K-T extinctions
AU - Chen, Guangqing
AU - Tyburczy, James
AU - Ahrens, Thomas J.
PY - 1994
Y1 - 1994
N2 - The devolatilization of calcium sulfate, which is present in the target rock of the Chicxulub, Mexico impact structure, and dispersal in the stratosphere of the resultant sulfuric acid aerosol have been suggested as a possible mechanism for the Cretaceous-Tertiary extinctions [1,2]. We measured the amount of SO2 produced from two shock-induced devolatilization reactions of calcium sulfate up to 42 GPa in the laboratory: CaSO4+SiO2→CaSiO3+SO3↑CaSO4→CaO+SO2↑+ 1 2O2↑. We found both to proceed to a much lower extent than calculated by equilibrium thermodynamic calculations. Reaction products are found to be ∼ 10-2 times those calculated for equilibrium. Upon modeling the quantity of sulfur oxides degassed into the atmosphere from shock devolatilization of CaSO4 in the Chicxulub lithographic section, the resulting 9 × 1016 to 6 × 1017 g (in sulfur mass) is lower by a factor of 10-100 than previous upper limit estimates, the related environmental stress arising from the resultant global cooling and fallout of acid rain is insufficient to explain the widespread K-T extinctions.
AB - The devolatilization of calcium sulfate, which is present in the target rock of the Chicxulub, Mexico impact structure, and dispersal in the stratosphere of the resultant sulfuric acid aerosol have been suggested as a possible mechanism for the Cretaceous-Tertiary extinctions [1,2]. We measured the amount of SO2 produced from two shock-induced devolatilization reactions of calcium sulfate up to 42 GPa in the laboratory: CaSO4+SiO2→CaSiO3+SO3↑CaSO4→CaO+SO2↑+ 1 2O2↑. We found both to proceed to a much lower extent than calculated by equilibrium thermodynamic calculations. Reaction products are found to be ∼ 10-2 times those calculated for equilibrium. Upon modeling the quantity of sulfur oxides degassed into the atmosphere from shock devolatilization of CaSO4 in the Chicxulub lithographic section, the resulting 9 × 1016 to 6 × 1017 g (in sulfur mass) is lower by a factor of 10-100 than previous upper limit estimates, the related environmental stress arising from the resultant global cooling and fallout of acid rain is insufficient to explain the widespread K-T extinctions.
UR - http://www.scopus.com/inward/record.url?scp=0028588340&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028588340&partnerID=8YFLogxK
U2 - 10.1016/0012-821X(94)90174-0
DO - 10.1016/0012-821X(94)90174-0
M3 - Article
VL - 128
SP - 615
EP - 628
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
SN - 0012-821X
IS - 3-4
ER -