Ancient Igneous Intrusions and Early Expansion of the Moon Revealed by GRAIL Gravity Gradiometry

作者：Andrews Hanna Jeffrey C^*; Asmar Sami W; Head James W III; Kiefer Walter S; Konopliv Alexander S; Lemoine Frank G; Matsuyama Isamu; Mazarico Erwan; McGovern Patrick J; Melosh H Jay; Neumann Gregory A; Nimmo Francis; Phillips Roger J; Smith David E; Solomon Sean C; Taylor G Jeffrey; Wieczorek Mark A; Williams James G; Zuber Maria T

来源：Science, 2013, 339(6120): 675-678.

DOI：10.1126/science.1231753

The earliest history of the Moon is poorly preserved in the surface geologic record due to the high flux of impactors, but aspects of that history may be preserved in subsurface structures. Application of gravity gradiometry to observations by the Gravity Recovery and Interior Laboratory (GRAIL) mission results in the identification of a population of linear gravity anomalies with lengths of hundreds of kilometers. Inversion of the gravity anomalies indicates elongated positive-density anomalies that are interpreted to be ancient vertical tabular intrusions or dikes formed by magmatism in combination with extension of the lithosphere. Crosscutting relationships support a pre-Nectarian to Nectarian age, preceding the end of the heavy bombardment of the Moon. The distribution, orientation, and dimensions of the intrusions indicate a globally isotropic extensional stress state arising from an increase in the Moon%26apos;s radius by 0.6 to 4.9 kilometers early in lunar history, consistent with predictions of thermal models.

• 出版日期2013-2-8