TY - JOUR
T1 - The chronostratigraphy of protoplanet Vesta
AU - Williams, David
AU - Jaumann, R.
AU - McSween, H. Y.
AU - Marchi, S.
AU - Schmedemann, N.
AU - Raymond, C. A.
AU - Russell, C. T.
N1 - Funding Information:
We thank Paul K. Byrne and Nicholas Lang for helpful reviews. The authors also thank the NASA Dawn Science and Flight Teams at the Jet Propulsion Laboratory for their tireless work that enabled the successful Vesta encounter, and the instrument teams at the Max Planck Institute, the German Aerospace Center (DLR), the Italian National Institute of Astrophysics (INAF), and the Planetary Science Institute for collecting and processing the data that enabled this study. DAW was funded through grant number NNX10AR24G from the NASA Dawn at Vesta Participating Scientists Program. The data used in this paper are available from the website http://dawndata.igpp.ucla.edu .
Publisher Copyright:
© 2014 Elsevier Inc.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - In this paper we present a time-stratigraphic scheme and geologic time scale for the protoplanet Vesta, based on global geologic mapping and other analyses of NASA Dawn spacecraft data, complemented by insights gained from laboratory studies of howardite-eucrite-diogenite (HED) meteorites and geophysical modeling. On the basis of prominent impact structures and their associated deposits, we propose a time scale for Vesta that consists of four geologic time periods: Pre-Veneneian, Veneneian, Rheasilvian, and Marcian. The Pre-Veneneian Period covers the time from the formation of Vesta up to the Veneneia impact event, from 4.6. Ga to >2.1. Ga (using the asteroid flux-derived chronology system) or from 4.6. Ga to 3.7. Ga (under the lunar-derived chronology system). The Veneneian Period covers the time span between the Veneneia and Rheasilvia impact events, from >2.1 to 1. Ga (asteroid flux-derived chronology) or from 3.7 to 3.5. Ga (lunar-derived chronology), respectively. The Rheasilvian Period covers the time span between the Rheasilvia and Marcia impact events, and the Marcian Period covers the time between the Marcia impact event until the present. The age of the Marcia impact is still uncertain, but our current best estimates from crater counts of the ejecta blanket suggest an age between ~120 and 390. Ma, depending upon choice of chronology system used. Regardless, the Marcia impact represents the youngest major geologic event on Vesta. Our proposed four-period geologic time scale for Vesta is, to a first order, comparable to those developed for other airless terrestrial bodies.
AB - In this paper we present a time-stratigraphic scheme and geologic time scale for the protoplanet Vesta, based on global geologic mapping and other analyses of NASA Dawn spacecraft data, complemented by insights gained from laboratory studies of howardite-eucrite-diogenite (HED) meteorites and geophysical modeling. On the basis of prominent impact structures and their associated deposits, we propose a time scale for Vesta that consists of four geologic time periods: Pre-Veneneian, Veneneian, Rheasilvian, and Marcian. The Pre-Veneneian Period covers the time from the formation of Vesta up to the Veneneia impact event, from 4.6. Ga to >2.1. Ga (using the asteroid flux-derived chronology system) or from 4.6. Ga to 3.7. Ga (under the lunar-derived chronology system). The Veneneian Period covers the time span between the Veneneia and Rheasilvia impact events, from >2.1 to 1. Ga (asteroid flux-derived chronology) or from 3.7 to 3.5. Ga (lunar-derived chronology), respectively. The Rheasilvian Period covers the time span between the Rheasilvia and Marcia impact events, and the Marcian Period covers the time between the Marcia impact event until the present. The age of the Marcia impact is still uncertain, but our current best estimates from crater counts of the ejecta blanket suggest an age between ~120 and 390. Ma, depending upon choice of chronology system used. Regardless, the Marcia impact represents the youngest major geologic event on Vesta. Our proposed four-period geologic time scale for Vesta is, to a first order, comparable to those developed for other airless terrestrial bodies.
KW - Asteroid vesta
KW - Asteroids, surfaces
KW - Geological processes
KW - Impact processes
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U2 - 10.1016/j.icarus.2014.06.027
DO - 10.1016/j.icarus.2014.06.027
M3 - Article
AN - SCOPUS:85027947052
SN - 0019-1035
VL - 244
SP - 158
EP - 165
JO - Icarus
JF - Icarus
ER -