Publication Date:
2019-07-13
Description:
Given the broad agreement between C, H, and O isotopic ratios in the modern atmosphere and the ALH 84001 meteorite, it is possible that these reservoirs were established after early atmospheric loss prior to 4 Ga. The preservation of these signals over this long period of history can be explained in several slightly different ways: 1) C, O, and H have remained static in the atmosphere and have not exchanged with the surface over the past 4 Ga; 2) C, O, and H in the atmosphere have potentially varied widely over history but have been continually buffered by larger reservoirs in the crust which have remained unchanged over the past 4 Ga. This second possibility allows for potentially large variations in atmospheric pressure to occur as CO2 is recycled back into the atmosphere from crustal reservoirs or degassed from the mantle.
Keywords:
Space Sciences (General)
Type:
JSC-CN-28406
,
Lunar and Planetary Science Conference; Mar 18, 2013 - Mar 22, 2013; The Woodlands, TX; United States
Format:
application/pdf
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