Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Structure and evolution of the lunar Procellarum region as revealed by GRAIL gravity data


The Procellarum region is a broad area on the nearside of the Moon that is characterized by low elevations1, thin crust2, and high surface concentrations of the heat-producing elements uranium, thorium, and potassium3,4. The region has been interpreted as an ancient impact basin approximately 3,200 kilometres in diameter5,6,7, although supporting evidence at the surface would have been largely obscured as a result of the great antiquity and poor preservation of any diagnostic features. Here we use data from the Gravity Recovery and Interior Laboratory (GRAIL) mission8 to examine the subsurface structure of Procellarum. The Bouguer gravity anomalies and gravity gradients reveal a pattern of narrow linear anomalies that border Procellarum and are interpreted to be the frozen remnants of lava-filled rifts and the underlying feeder dykes that served as the magma plumbing system for much of the nearside mare volcanism. The discontinuous surface structures that were earlier interpreted as remnants of an impact basin rim are shown in GRAIL data to be a part of this continuous set of border structures in a quasi-rectangular pattern with angular intersections, contrary to the expected circular or elliptical shape of an impact basin9. The spatial pattern of magmatic-tectonic structures bounding Procellarum is consistent with their formation in response to thermal stresses produced by the differential cooling of the province relative to its surroundings, coupled with magmatic activity driven by the greater-than-average heat flux in the region.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Global maps of lunar properties.
Figure 2: Gravity and subsurface structure of the PKT border structures.
Figure 3: Geometric pattern of the PKT border structures, with a comparison to the Enceladus SPT.
Figure 4: Predicted temperature and stress for the Procellarum region.


  1. 1

    Smith, D. E. et al. Initial observations from the Lunar Orbiter Laser Altimeter (LOLA). Geophys. Res. Lett. 37, L18204 (2010)

    ADS  Google Scholar 

  2. 2

    Wieczorek, M. A. et al. The crust of the Moon as seen by GRAIL. Science 339, 671–675 (2013)

    ADS  CAS  PubMed  Article  Google Scholar 

  3. 3

    Jolliff, B. L. et al. Major lunar crustal terranes: surface expressions and crust-mantle origins. J. Geophys. Res. 105, 4197–4216 (2000)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Lawrence, D. J. et al. Global elemental maps of the Moon: the Lunar Prospector gamma-ray spectrometer. Science 281, 1484–1489 (1998)

    ADS  CAS  PubMed  Article  Google Scholar 

  5. 5

    Whitaker, E. A. The lunar Procellarum basin. Lunar Planet. Sci. 12A, 105–111 (1981)

    Google Scholar 

  6. 6

    Cadogan, P. H. Oldest and largest lunar basin? Nature 250, 315–316 (1974)

    ADS  Article  Google Scholar 

  7. 7

    Wilhelms, D. E. The geological history of the Moon. US Geol. Surv. Prof. Pap. 1348, 1–302 (1987)

    Google Scholar 

  8. 8

    Zuber, M. T. et al. Gravity field of the Moon from the Gravity Recovery and Interior Laboratory (GRAIL) mission. Science 339, 668–671 (2013)

    ADS  CAS  PubMed  Article  Google Scholar 

  9. 9

    Andrews-Hanna, J. C. & Zuber, M. T. in Large Meteorite Impacts and Planetary Evolution IV (eds Gibson, R. L. & Reimold, W. U. ) 1–13 (Special Paper 465, Geological Society of America, 2010)

    Google Scholar 

  10. 10

    Wieczorek, M. A. & Phillips, R. J. The “Procellarum KREEP Terrane”: implications for mare volcanism and lunar evolution. J. Geophys. Res. 105, 20417–20430 (2000)

    ADS  CAS  Article  Google Scholar 

  11. 11

    Grimm, R. E. Geophysical constraints on the lunar Procellarum KREEP Terrane. J. Geophys. Res. Planets 118, 768–777 (2013)

    ADS  Article  Google Scholar 

  12. 12

    Laneuville, M., Wieczorek, M. A., Breuer, D. & Tosi, N. Asymmetric thermal evolution of the Moon. J. Geophys. Res. Planets 118, 1435–1452 (2013)

    ADS  Article  Google Scholar 

  13. 13

    Nakamura, R. et al. Compositional evidence for an impact origin of the Moon’s Procellarum basin. Nature Geosci. 5, 775–778 (2012)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Andrews-Hanna, J. C. et al. Ancient igneous intrusions and early expansion of the Moon revealed by GRAIL gravity gradiometry. Science 339, 675–678 (2013)

    ADS  CAS  PubMed  Article  Google Scholar 

  15. 15

    Scott, D. H. The geologic significance of some lunar gravity anomalies. Proc. Lunar Sci. Conf. 5, 3025–3036 (1974)

    ADS  Google Scholar 

  16. 16

    White, R. & McKenzie, D. Magmatism at rift zones: the generation of volcanic continental margins and flood basalts. J. Geophys. Res. 94, 7685–7729 (1989)

    ADS  Article  Google Scholar 

  17. 17

    Hiesinger, H. et al. Ages and stratigraphy of lunar mare basalts in Mare Frigoris and other nearside maria based on crater size-frequency distribution measurements. J. Geophys. Res. 115, E03003 (2010)

    ADS  Article  CAS  Google Scholar 

  18. 18

    Andrews-Hanna, J. C., Zuber, M. T. & Banerdt, W. B. The Borealis basin and the origin of the martian crustal dichotomy. Nature 453, 1212–1215 (2008)

    ADS  CAS  PubMed  Article  Google Scholar 

  19. 19

    Watters, T. R. & Johnson, C. L. in Planetary Tectonics (eds Watters, T. R. & Schultz, R. A. ) 121–182 (Cambridge Univ. Press, 2010)

    Google Scholar 

  20. 20

    Melosh, H. J. & Raefsky, A. The dynamical origin of subduction zone topography. Geophys. J. R. Astron. Soc. 60, 333–354 (1980)

    ADS  Article  Google Scholar 

  21. 21

    Solomon, S. C. The relationship between crustal tectonics and internal evolution in the Moon and Mercury. Phys. Earth Planet. Inter. 15, 135–145 (1977)

    ADS  Article  Google Scholar 

  22. 22

    McGovern, P. J., Rumpf, M. E. & Zimbelman, J. R. The influence of lithospheric flexure and volcano shape on magma ascent at large volcanoes on Venus. J. Geophys. Res. Planets 118, 2423–2437 (2013)

    ADS  CAS  Article  Google Scholar 

  23. 23

    Hiesinger, H. & Head, J. W. Characteristics and origin of polygonal terrain in southern Utopia Planitia, Mars: results from Mars Orbiter Laser Altimeter and Mars Orbiter Camera data. J. Geophys. Res. 105, 11999–12022 (2000)

    ADS  Article  Google Scholar 

  24. 24

    Porco, C. C. et al. Cassini observed the active south pole of Enceladus. Science 311, 1393–1401 (2006)

    ADS  CAS  PubMed  Article  Google Scholar 

  25. 25

    Schenk, P. M. & McKinnon, W. B. One-hundred-km-scale basins on Enceladus: evidence for an active ice shell. Geophys. Res. Lett. 36, L16202 (2009)

    ADS  Article  Google Scholar 

  26. 26

    Howett, C. J. A., Spencer, J. R., Pearl, J. & Segura, M. High heat flow from Enceladus’ south polar region measured using 10–600 cm−1 Cassini/CIRS data. J. Geophys. Res. 116, E03003 (2011)

    ADS  Article  CAS  Google Scholar 

  27. 27

    Běhounková, M., Tobie, G., Choblet, G. & Cadek, O. Tidally-induced melting events as the origin of south-pole activity on Enceladus. Icarus 219, 655–664 (2012)

    ADS  Article  Google Scholar 

  28. 28

    O’Neil, C. & Nimmo, F. The role of episodic overturn in generating the surface geology and heat flow on Enceladus. Nature Geosci. 3, 88–91 (2010)

    ADS  Article  CAS  Google Scholar 

  29. 29

    Zuber, M. T. et al. Topography of the northern hemisphere of Mercury from MESSENGER laser altimetry. Science 336, 217–220 (2012)

    ADS  CAS  PubMed  Article  Google Scholar 

  30. 30

    Head, J. W. et al. Flood volcanism in the northern high latitudes of Mercury revealed by MESSENGER. Science 333, 1853–1856 (2011)

    ADS  CAS  PubMed  Article  PubMed Central  Google Scholar 

  31. 31

    Lemoine, F. G. et al. GRGM900C: A degree 900 lunar gravity model from GRAIL primary and extended mission data. Geophys. Res. Lett. 41, 3382–3389 (2014)

    ADS  PubMed  PubMed Central  Article  Google Scholar 

  32. 32

    Reed, G. B. Application of Kinematical Geodesy for Determining Short Wave Length Components of the Gravity Field by Satellite Gradiometry (Tech. Rep. 201, Department of Geodetic Science, The Ohio State University, 1973)

    Google Scholar 

  33. 33

    Wieczorek, M. A. & Phillips, R. J. Potential anomalies on a sphere: applications to the thickness of the lunar crust. J. Geophys. Res. 103, 1715–1724 (1998)

    ADS  Article  Google Scholar 

  34. 34

    Kiefer, W. S. et al. The density and porosity of lunar rocks. Geophys. Res. Lett. 39, L07201 (2012).

    ADS  Article  CAS  Google Scholar 

  35. 35

    Parmentier, E. M., Zhong, S. & Zuber, M. T. Gravitational differentiation due to initial chemical stratification: origin of lunar asymmetry by the creep of dense KREEP? Earth Planet. Sci. Lett. 201, 473–480 (2002)

    ADS  CAS  Article  Google Scholar 

  36. 36

    Hess, P. C. & Parmentier, E. M. A model for the thermal and chemical evolution of the Moon’s interior: implications for the onset of mare volcanism. Earth Planet. Sci. Lett. 134, 501–514 (1995)

    ADS  CAS  Article  Google Scholar 

  37. 37

    Elkins-Tanton, L. T., Burgess, S. & Yin, Q.-Z. The lunar magma ocean: reconciling the solidification process with lunar petrology and geochronology. Earth Planet. Sci. Lett. 304, 326–336 (2011)

    ADS  CAS  Article  Google Scholar 

  38. 38

    Elkins Tanton, L. T., Van Orman, J. A., Hager, B. H. & Grove, T. L. Re-examination of the lunar magma ocean cumulate overturn hypothesis: melting or mixing is required. Earth Planet. Sci. Lett. 196, 239–249 (2002)

    ADS  CAS  Article  Google Scholar 

  39. 39

    DeHon, R. A. Maximum thickness of materials in the western mare basins. Proc. Lunar Planet. Sci. Conf. 9, 229–231 (1978)

    ADS  Google Scholar 

  40. 40

    Blakely, R. J. Potential Theory in Gravity and Magnetic Applications (Cambridge Univ. Press, 1995)

    Book  Google Scholar 

  41. 41

    Hiesinger, H., Jaumann, R., Neukum, G. & Head, J. W. Ages of mare basalts on the lunar nearside. J. Geophys. Res. 105, 29239–29275 (2000)

    ADS  Article  Google Scholar 

  42. 42

    Hiesinger, H. et al. Ages and stratigraphy of mare basalts in Oceanus Procellarum, Mare Nubium, Mare Cognitum, and Mare Insularum. J. Geophys. Res. 108, 5065 (2003)

    Article  Google Scholar 

  43. 43

    Pritchard, M. E. & Stevenson, D. J. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K. ) 179–196 (Univ. Arizona Press, 2000)

    Google Scholar 

  44. 44

    Toksöz, M. N., Dainty, A. M., Solomon, S. C. & Anderson, K. R. Structure of the Moon. Rev. Geophys. Space Phys. 12, 539–567 (1974)

    ADS  Article  Google Scholar 

  45. 45

    Presley, M. A. & Christensen, P. R. Thermal conductivity measurements of particulate materials: 4. Effect of bulk density for granular particles. J. Geophys. Res. 115, E07003 (2010)

    ADS  Google Scholar 

  46. 46

    Besserer, J. et al. Theoretical and observational constraints on lunar mega-regolith thickness. Lunar Planet. Sci. 44, abstr. 2463. (2013)

  47. 47

    Turcotte, D. L. & Schubert, G. Geodynamics 2nd edn (Cambridge Univ. Press, 2001)

    Google Scholar 

  48. 48

    Buck, W. R. Modes of continental lithospheric extension. J. Geophys. Res. 96, 20161–20178 (1991)

    ADS  Article  Google Scholar 

  49. 49

    McGovern, P. J. et al. Impact-generated loading and lithospheric stress gradients at lunar impact basins: implications for maria emplacement scenarios. Lunar Planet. Sci. 44, abstr. 3055. (2013)

  50. 50

    Wilson, L. & Head, J. W. Ascent and eruption of basaltic magma on the Earth and Moon. J. Geophys. Res. 86, 2971–3001 (1981)

    ADS  Article  Google Scholar 

  51. 51

    Lachenbruch, A. H. Mechanics of thermal contraction cracks and ice-wedge polygons in permafrost. Spec. Pap. Geol. Soc. Am. 70, 1–66 (1962)

    Google Scholar 

  52. 52

    Spencer, J. R. et al. Enceladus heat flow from high spatial resolution thermal emission observations. EPSC Abstr. 8, EPSC2013–2840-2011 (2013)

    Google Scholar 

  53. 53

    Spencer, J. R. et al. Cassini encounters Enceladus: background and the discovery of a south polar hot spot. Science 311, 1401–1405 (2006)

    ADS  CAS  PubMed  Article  Google Scholar 

  54. 54

    Roberts, J. H. & Nimmo, F. Near-surface heating on Enceladus and the south polar thermal anomaly. Geophys. Res. Lett. 35, L09201 (2008)

    ADS  Google Scholar 

  55. 55

    Tobie, G., Cadek, O. & Sotin, C. Solid tidal friction above a liquid water reservoir as the origin of the south pole hotspot on Enceladus. Icarus 196, 642–652 (2008)

    ADS  CAS  Article  Google Scholar 

  56. 56

    Thomas, P. C. et al. Shapes of the Saturnian icy satellites and their significance. Icarus 190, 573–584 (2007)

    ADS  CAS  Article  Google Scholar 

  57. 57

    Iess, L. et al. The gravity field and interior structure of Enceladus. Science 344, 78–80 (2014)

    ADS  CAS  PubMed  Article  Google Scholar 

  58. 58

    Collins, G. C. & Goodman, J. C. Enceladus’ south polar sea. Icarus 189, 72–82 (2007)

    ADS  Article  Google Scholar 

  59. 59

    Besserer, J., Nimmo, F., Roberts, J. H. & Pappalardo, R. T. Convection-driven compaction as a possible origin of Enceladus’s long wavelength topography. J. Geophys. Res. Planets 118, 908–915 (2013)

    ADS  Article  Google Scholar 

  60. 60

    Nimmo, F., Spencer, J. R., Pappalardo, R. T. & Mullen, M. E. Shear heating as the origin of the plumes and heat flux on Enceladus. Nature 447, 289–291 (2007)

    ADS  CAS  PubMed  Article  Google Scholar 

  61. 61

    Meyer, J. & Wisdom, J. Tidal heating in Enceladus. Icarus 188, 535–539 (2007)

    ADS  Article  Google Scholar 

  62. 62

    Lainey, V. et al. Strong tidal dissipation in Saturn and constraints on Enceladus’ thermal state from astrometry. Astrophys. J. 752, 14 (2012)

    ADS  Article  Google Scholar 

  63. 63

    Barr, A. C. Mobile lid convection beneath Enceladus’ south polar terrain. J. Geophys. Res. 113, E07009 (2008)

    ADS  Article  CAS  Google Scholar 

  64. 64

    Bland, M. T., Singer, K. N., McKinnon, W. B. & Schenk, P. M. Enceladus’ extreme heat flux as revealed by its relaxed craters. Geophys. Res. Lett. 39, L17204 (2012)

    ADS  Article  CAS  Google Scholar 

  65. 65

    Giese, B. et al. Enceladus: an estimate of heat flux and lithospheric thickness from flexurally supported topography. Geophys. Res. Lett. 35, L24204 (2008)

    ADS  Article  Google Scholar 

  66. 66

    Crow-Willard, E. & Pappalardo, R. T. Global geological mapping of Enceladus. EPSC Abstr. 6, EPSC–DPS2011-2635-2011 (2011)

  67. 67

    Spencer, J. R. et al. in Saturn from Cassini-Huygens (eds Dougherty, M. K., Esposito, L. W. & Krimigis, S. M. ) 683–724 (Springer, 2009)

  68. 68

    Walker, C. C., Bassis, J. N. & Liemohn, M. W. On the application of simple rift basin models to the south polar region of Enceladus. J. Geophys. Res. 117, E07003 (2012)

    ADS  Article  CAS  Google Scholar 

  69. 69

    Yin, A. & Pappalardo, R. T. Left-slip faulting along the tiger stripe fractures: implications for the tectonic evolution of the south polar terrain, Enceladus. Lunar Planet. Sci. 44, abstr. 1145. (2013)

    ADS  Google Scholar 

  70. 70

    Gioia, G., Chakraborty, P., Marshak, S. & Kieffer, S. Unified model of tectonics and heat transport in a frigid Enceladus. Proc. Natl Acad. Sci. USA 104, 13578–13581 (2007)

    ADS  CAS  PubMed  Article  Google Scholar 

  71. 71

    Barr, A. C. & Preuss, L. J. On the origin of the south polar folds on Enceladus. Icarus 208, 499–503 (2010)

    ADS  Article  Google Scholar 

  72. 72

    Hurford, T. A. et al. Eruptions arising from tidally controlled periodic openings of rifts on Enceladus. Nature 447, 292–294 (2007)

    ADS  CAS  PubMed  Article  PubMed Central  Google Scholar 

Download references


The GRAIL mission is a component of the NASA Discovery Program and is performed under contract to the Massachusetts Institute of Technology and the Jet Propulsion Laboratory, California Institute of Technology. J.C.A.-H. was supported by grant NNX12AL20G from NASA’s GRAIL Guest Scientist Program.

Author information




J.C.A.-H. performed the data analyses and modelling. M.T.Z. is the principal investigator of the GRAIL mission. All authors contributed to the interpretation of the results and their implications.

Corresponding author

Correspondence to Jeffrey C. Andrews-Hanna.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Comparison of the GRAIL gravity gradients with proposed Procellarum basin ring structures.

a, Bouguer gravity gradients (in units of Eötvös; 1 E = 10−9 s−2) on a Lambert azimuthal equal-area projection of the nearside of the Moon. b, Muted gravity gradients overlaid with mapped mare boundaries and scarps (dots) and wrinkle ridges (lines). Modified from figure 1 of ref. 5 with permission.

Extended Data Figure 2 Amplitudes of filters applied during the crustal thickness modelling.

a, b, Filters were applied during the calculation of the relief along the crust–mantle interface (solid lines) and the mare–basement interface (dashed lines) for cases in which the relief along the two interfaces was either isostatic before mare loading (a) or equal and opposite in amplitude (b). The filter in b imposes the isostatic condition from degrees 1 to 3 and a linear transition to the equal-amplitude filter from degrees 3 to 10. Both filters apply a cosine taper from degrees 125 to 150. The mare–basement filter is shown for illustration purposes only. In practice, the relief along the mare–basement interface was calculated from the residual Bouguer anomaly after the calculation of the crust–mantle interface relief (equivalent to using the filter shown with the original Bouguer gravity).

Extended Data Figure 3 Predicted thicknesses of the crust and maria and average cross-sections across two of the border anomalies.

Predicted thickness of the maria (left column) and underlying feldspathic crust (middle column), and cross-sections of the modelled structures of anomaly 1 (right column, top) and anomaly 2 (right column, bottom) showing the variations in the thicknesses of the mare (dark grey) and feldspathic crust (light grey). Models are for cases as follows: ad, isostatic relief along the two interfaces before mare infilling with a mantle density of 3,220 kg m−3; eh, equal-amplitude relief along the two interfaces with a mantle density of 3,220 kg m−3; il, isostatic relief along the two interfaces before mare infilling with a mantle density of 3,500 kg m−3; mp, equal-amplitude relief along the two interfaces with a mantle density of 3,500 kg m−3; qt, all gravity anomalies at degrees >10 ascribed to relief on the mare–basement interface; and u-x, all gravity anomalies at degrees >10 ascribed to relief on the crust-mantle interface.

Extended Data Figure 4 Temperature evolution within and outside the PKT.

a, The temperatures as functions of time at a depth of 25 km are shown within the PKT for cases in which KREEP-rich material is either concentrated at the base of the crust (solid line) or is distributed throughout the crust (dashed line), as well as the temperature outside the PKT (dotted line). The period between 4.0 and 3.0 Gyr ago that is the focus of the stress modelling is indicated by the shaded box. b, c, The temperatures as functions of depth both inside and outside the PKT are shown for KREEP-rich material concentrated at the base of the crust (b) and for KREEP-rich material distributed throughout the crust (c).

Extended Data Figure 5 Predicted changes in temperature relative to areas outside the PKT and absolute temperature change between 4.0 and 3.0 Gyr ago.

Results are shown for cases with KREEP concentrated at the base of the crust (a, b) and KREEP distributed throughout the crust (c, d). The PKT is centred on the pole at the left side of the panels. The region shown in Extended Data Figs 6 and 7 (encompassing 90° of arc extending radially outward from the centre of the PKT and downward to a depth of 50 km) is outlined in black.

Extended Data Figure 6 Predicted lithospheric stresses and magma ascent for the case of 10 km of KREEP at the base of the crust.

Cross-sections show the following: a, the in-plane horizontal stresses (radial to the centre of the PKT, the far-field stress profile was subtracted to calculate the relative stress); b, the difference between the in-plane horizontal stress and the vertical stress; c, the magma ascent criteria; and d, the deviatoric stress. The magma ascent criteria in c reveal portions of the crust in which the horizontal stresses are tensile relative to the vertical stresses to permit the formation of vertical dykes (dark grey), where the vertical stress gradient is more favourable to magma ascent than the lithosphere far from the PKT (light grey), where magma will rise unassisted by other factors such as pressurized magma chambers (red), and where none of the criteria are satisfied (diagonal lines).

Extended Data Figure 7 Predicted lithospheric stresses and magma ascent for the case of 10 km of KREEP basalt distributed uniformly through a 40-km-thick crust.

All panels are as for Extended Data Fig. 6.

Extended Data Figure 8 Additional comparisons of Procellarum KREEP terrane to the Enceladus south polar terrain (SPT).

a, The PKT is characterized by high heat flow as a result of the enhanced abundances of radioactive elements3 (represented by the concentration of thorium4). b, The border structures of the SPT as revealed by Cassini ISS images24 also trace a quasi-rectangular pattern enclosing a region of elevated brightness temperatures and enhanced heat flow26 (c) All maps are in a simple polar projection. In all panels, the circle corresponds to an angular diameter of 180° of surface arc, divided into 10° increments.

Extended Data Table 1 Extension and strain across two border anomalies

Related audio

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Andrews-Hanna, J., Besserer, J., Head III, J. et al. Structure and evolution of the lunar Procellarum region as revealed by GRAIL gravity data. Nature 514, 68–71 (2014).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing