US EPA

4958428 

Journal Article 

Widespread effusive volcanism on Mercury likely ended by about 3.5Ga 

Byrne, PK; Ostrach, LR; Fassett, CI; Chapman, CR; Denevi, BW; Evans, AJ; Klimczak, C; Banks, ME; Head, JW; Solomon, SC 

2016 

Yes 

Geophysical Research Letters
ISSN: 0094-8276
EISSN: 1944-8007 

43 

14 

7408-7416 

10.1002/2016GL069412 

WOS:000383290200016 

Crater size-frequency analyses have shown that the largest volcanic plains deposits on Mercury were emplaced around 3.7Ga, as determined with recent model production function chronologies for impact crater formation on that planet. To test the hypothesis that all major smooth plains on Mercury were emplaced by about that time, we determined crater size-frequency distributions for the nine next-largest deposits, which we interpret also as volcanic. Our crater density measurements are consistent with those of the largest areas of smooth plains on the planet. Model ages based on recent crater production rate estimates for Mercury imply that the main phase of plains volcanism on Mercury had ended by similar to 3.5Ga, with only small-scale volcanism enduring beyond that time. Cessation of widespread effusive volcanism is attributable to interior cooling and contraction of the innermost planet. 

Mercury; volcanism; crater size-frequency distributions; global contraction; impact cratering