The 1:2,500,000-scale geologic map of the global Moon

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Short Communications
The 1:2,500,000-scale geologic map of the global moon
Jinzhu Ji, Dijun Guo, Jianzhong Liu, Shengbo Chen, Zongcheng Ling,
Xiaozhong Ding, Kunying Han, Jianping Chen, Weiming Cheng, Kai Zhu,
Jingwen Liu, Juntao Wang, Jian Chen, Ziyuan Ouyang
PII: S2095-9273(22)00231-6
DOI: https://doi.org/10.1016/j.scib.2022.05.021
Reference: SCIB 1774
To appear in: Science Bulletin
Received Date: 13 April 2022
Revised Date: 10 May 2022
Accepted Date: 13 May 2022
Please cite this article as: J. Ji, D. Guo, J. Liu, S. Chen, Z. Ling, X. Ding, K. Han, J. Chen, W. Cheng, K. Zhu, J.
Liu, J. Wang, J. Chen, Z. Ouyang, The 1:2,500,000-scale geologic map of the global moon, Science Bulletin
(2022), doi: https://doi.org/10.1016/j.scib.2022.05.021
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Short Communication
The 1:2,500,000-scale geologic map of the global Moon
Jinzhu Jia,g†, Dijun Guoh†, Jianzhong Liua,i,*, Shengbo Chenb,i, Zongcheng Lingc,i, Xiaozhong Dingd,
Kunying Hand, Jianping Chene, Weiming Chengf,i, Kai Zhua, Jingwen Liua,j, Juntao Wanga, Jian Chenc,
Ziyuan Ouyanga
a Center for Lunar and Planetary Science, Institute of Geochemistry, Chinese Academy of Sciences,
Guiyang 550081, China
b College of Geoexploration Science and Technology, Jilin University, Changchun 130000, China
c Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space
Sciences, School of Space Science and Physics, Shandong University, Weihai 264209, China
d Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China
e School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
f State Key Laboratory of Resources and Environmental Information Systems, Institute of Geographic
Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
g School of Mining, Inner Mongolia University of Technology, Hohhot 010051, China
h National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China
i Center for Excellence in Comparative Planetology, Chinese Academy of Sciences, Hefei 230026, China
j College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049,
China
* Corresponding author, e-mail: liujz@mail.gyig.ac.cn
†These authors contributed equally to this work.
Received 2022-04-13，revised 2022-05-10，accepted 2022-05-13

Geologic maps of the Moon provide comprehensive information about the geologic
strata, structural features, lithologies, and chronology of the lunar crustal surface, which
reflect the evolution of lunar crust under igneous processes, catastrophic impacts, and
volcanic activities [1]. As syntheses of current knowledge on lunar geology and evolution
history, lunar geologic maps are fundamental resources in science research, exploration
planning, and landing site selection. In the Moon Race era from the late 1950s to mid
1970s, huge amounts of data were obtained through a volley of robotic and crewed
missions, in which the Apollo and Luna missions set the greatest milestones by returning
~382 kg lunar samples in total. Using the data returned from the Moon and collected
through Earth-based telescopes, the United States Geological Survey (USGS) compiled
seven atlases of lunar regional geologic maps at scales of 1:5,000,000, 1:250,000,
1:100,000, 1:50,000, 1: 5000, 1:10,000, and 1:5000. However, those maps were compiled
using different standards because they were completed by different groups in different
periods of time, and often lead to confusion and misunderstanding. Though the six
1:5,000,000-scale quadrangular maps can cover the entire Moon in combination [2], their
unit schemes are not compatible with each other. After being digitalized and adjusting the
203 units across the six maps to 43 unified units, Fortezzo et al. [2] stitched the six maps
together and released a globally consistent 1:5,000,000-scale geologic map.
Since the 1990s, the lunar exploration has entered a new booming phase and nearly
20 spacecrafts have been launched to the Moon from not only the US but also new
agencies such as China, India, and Japan. Benefitting from those missions,
unprecedented exploration data and new discoveries have profoundly renewed our
understanding of the geologic processes and evolution of the Moon. However, the
integrated cartographic work had remained lagging until we initiated the 1:2,500,000-scale
lunar global mapping project, led by Ouyang Ziyuan and Liu Jianzhong. Although the
1:5,000,000-scale global geologic map is available [2], it is only a uniformity of the
previous quadrangular maps and does not incorporate the subsequent scientific advances
(Text S1 online). USGS also proposed to map the global Moon at 1:2,500,000 scale [3],
but little progress has been reported.
In this mapping work, one basic principle is to regard the lunar geologic units and
evolution history from the dynamic perspective, i.e., endogenous or exogenous. The
exploration datasets and products from China’s Lunar Exploration Program (CLEP) [4] are
used as the primary data (Table S1 online) for mapping geologic units. As important
supplementary data, we also collected the high-quality datasets and products from
international exploration missions (Table S1 online). The scale, 1:2,500,000, is restricted
by the resolution of the primary datasets on one hand, and with considerations of the
workload and compatibility with USGS 1:2,500,000-scale scheme on the other hand [3].
The global Moon was subdivided into 30 quadrangles and mapped individually with the
same standard and unit scheme. To minimize the map distortions, different map
projections are employed for different quadrangles depending on the latitudinal range (Fig.
S1 online). The Mercator projection is used for 0°–30°N/S; the Lambert conformal conic
projection is used for 30°–65°N/S; and the Polar stereographic projection is used for the

polar regions with latitude of 65°–90°N/S. Our mapping work was performed on ESRI
(Environmental Systems Research Institute) ArcMap platform, and all the maps have their
own geodatabases. The global map was created by stitching the 30 quadrangular maps
together.
The geologic time scale, which categorizes geologic units into different chronologic
periods with respect to the most significant evolutionary events, is the foundation for a
geologic map. The current lunar time scale was proposed by Wilhelms et al. [5], while the
past decades have seen great progresses in studying the geological evolution of the
Moon. From the dynamic perspective, the evolution of the Moon can be divided into three
phases [6, 7], and in different phases the endogenic and exogenic processes have made
relatively different contributions in shaping the lunar crust (Fig. 1). The first phase
specifically represents the magma ocean solidification period and was dominated by
endogenic processes. The formation of the oldest South Pole-Aitken (SPA) impact basin
at ~4.3 Ga [8] implies a transition in dynamics. In the second phase, the effects of
endogenic (igneous activities, magmatism, and volcanism) and exogenic (meteorite
impacts) processes were comparable. With the cooling of the Moon, the magnitude of
endogenic processes has declined since ~3.1–3.3 Ga and the magmatic products
became much less than previous periods, while impact craters have been continuously
formed on lunar surface. Thus, the exogenic processes has dominated over endogenic
processes in this period and it is the third lunar evolution phase. From a geochronologic
point of view, we defined three Eon/Eonothem-level time-scale units corresponding to the
three dynamical evolutionary phases, which are Eolunarian, Paleolunarian, and
Neolunarian from old to young (Fig. 1). However, the current Period-level units do not
readily fit in this scheme, as the Pre-Nectarian Period includes both the magma ocean
evolution and formations of the SPA and subsequent dozens of basins [5]. Therefore, the
pre-Nectarian Period is divided into Magma-oceanian and Aitkenian Periods [7], and the
ejecta deposit of the SPA basin, i.e., the Das Formation is defined as the stratigraphic
boundary (Fig. 1). The other Period-level units are unchanged from Wilhelms et al. [5]. So,
only by small modifications, the updated lunar time scale scheme shows great advantage
in highlighting the dynamic evolution of the Moon, which is important for revealing the
evolution history from geologic maps.
Fig. 1. The updated lunar time scale from the dynamic evolution perspective.
Following the principle of dynamic genesis (i.e., exogenic products or endogenic
products), with integrated considerations of previous maps, geologic architectures,
morphologic characteristics, compositional distribution, and structural features, there are
90 map units were expressed in our geologic map (Fig. S2 online). The exogenic units
include three groups: crater materials [9, 10] (Fig. S3 online), basin formations [11] (Fig.
S4 online), and structures formed in exogenic processes. It should be noted that a basin is

a crater in fact yet with highly-developed central peak or peak ring(s) and are usually
greater than 200 km diameter [11]. The endogenic units are categorized into two groups:
lithologies that formed in igneous and volcanic processes [12] (Fig. S5 online), and
geological structures of various types [13, 14] (Fig. S6 online). There are some locations
on lunar surface that have particular implications such as landing sites and elevation
points (the highest and lowest elevations in quadrangle maps). They are categorized in
the group of special features and are marked on maps. In accord with the map unit
scheme, we designed the standard legends for the 1:2,500,000-scale geologic maps [15]
(Fig. S7 online). The unit scheme and legend will be publicly available and can serve as a
basis for the other lunar geologic mapping scenarios.
More information about the geologic units is given as follows.
(1) Crater materials. Impact craters are the dominant features on the Moon, and the
cratering excavation is the most common geological process on the lunar crust. As a
result of the impact cratering mechanism, materials of a typical fresh crater usually appear
as five facies (Text S2 and Fig. S3 online): central peak, floor, wall, continuous ejecta, and
discontinuous ejecta. The central peak only appears in the crater with relatively greater
diameter (usually >15 km) and such a crater is called a complex crater. On our global map,
crater materials of 6153 dated and 1395 undated impact craters are identified and
mapped. Due to the morphologic degradation with age and space weathering effects,
some parts of the facies may be demolished and hardly recognized. In summary, the
global map includes 1265 central peak units, 6830 floor units, 7548 wall units, 4768
continuous ejecta units, and 79 discontinuous ejecta units.
(2) Basin formations. Impact basins are primary geological structures on the Moon
formed in ~4.3–3.8 Ga, and play key roles in revealing the lunar history. Based on the
characteristics observed from new high-resolution morphologic data and research results,
we established the criteria to define a basin and the basin types [11]. Under these criteria,
we produced a new lunar basin catalog with 81 basins, including 24 proto-basins, 31
peak-ring basins, 25 multiring basins, and 1 super basin specifically referring to the SPA
basin (Table S2 online). Based on the isotopic ages and crater size-frequency
distributions, there are 49 Aitkenian-aged basins, 25 Nectarian-aged basins, and 7
Imbrian-aged basins. Analysis of the ring-diameter ratios, pure anorthosite distribution,
and radial textures of basin ejecta suggests that the basin rock-stratigraphic units may
include six parts (Text S3 and Fig. S4 online): central peak, peak-ring, basin-floor,
basin-wall, basin-rim, and basin-ejecta [11]. These basin units are regarded as "geological
formation" referring to the lithostratigraphic unit having a consistent set of physical
characteristics that distinguishes it from an adjacent unit. Our geologic map shows that
the stratigraphic units of basins cover near 70% of the lunar surface, though those of most
basins are only partially preserved due to modification from late impact events and mare
basalts filling. Several basin-ejecta units are "Golden Spikes" used as the base strata of
lunar chronostratigraphy scheme, making them equivalent roles to the Global Standard
Straotype-section and Points (GSSP) (or "Golden Spike") in terrestrial chronostratigraphy
scheme. These include the Das Formation of the SPA basin, Janssen Formation of the

Nectaris basin, Fra Mauro Formation of the Imbrium basin, and Hevelius Formation of the
Orientale basin, which are the "Golden Spike" of the Moon.
(3) Endogenic lithologies. The types and distribution of lunar endogenic rocks are
important information for understanding the geologic evolution of the Moon. In the scheme
of our geologic map, the lunar endogenic lithology includes 17 rock types categorized into
three groups (Fig. S5 and Table S3 online): 5 types of mare basalts (very low-Ti, low-Ti,
medium-Ti, high-Ti, and very high-Ti), 7 types of non-mare rocks (ferroan noritic suite,
ferroan anorthositic suite, magnesian anorthositic suite, Mg-suite, Alkali suite, KREEP
suite, and KREEP basalt), and 5 special outcrops (pure anorthosite, spinel anorthosite,
olivine-rich outcrop, pyroclastic deposits, and silicic dome).
(4) Structures. The development and distribution of geological structures can reflect
the force conditions and mechanical properties of lunar crust. In our geologic map, we
mapped out 14 types of geologic structures classified into two groups considering their
dynamic genesis (Fig. S6 online). The structures usually appear as either linear shapes or
circular shapes. The 10 endogenic structure types consist of 16839 linear structures (358
inferred deep faults, 1335 shallow faults, 11046 wrinkle ridges, 474 rillles, 816 grabens,
2583 crater-floor fractures, and 227 lobate scarps) and 364 circular structures (271
volcanic vents, 47 domes, and 46 mascons). The 4 exogenic structure types consist of
2137 linear structures (1882 impact fractures and 255 impact crater chains) and 4874
circular structures (4793 impact craters and 81 impact basins). To avoid the bewildering
map elements, only the craters with recognizable morphologic characteristics but the
crater materials have been demolished and unmapped are expressed as circular
structures, while the craters whose crater materials are mapped are excluded in structure
features. The smallest craters and linear structures being mapped are 10 km in diameter
and 2.5 km in length, respectively.
(5) Special features. These include the landing sites of all the previous landing
exploration missions (i.e., Apollo, Luna, and Chang’e missions), locations of
chronostratigraphic "Golden spikes" (Das Formation, Janssen Formation, Fra Mauro
Formation, and Hevelius Formation), elevation peak and bottom of each quadrangle
(elevation points), and geological contacts.
Fig. 2. Thumbnail of the 1:2,500,000-scale global geologic map of the Moon. The global
map in the center is in Mollweide projection, and the north and south polar maps on the top are
in Polar stereographic projection. The maps in the center of the left and right sides are the
global lithologic map and global structure outline map, respectively.
The first 1:2,500,000-scale global geologic map of the Moon (Fig. 2) provides a
state-of-the-art illustration of impact basins, craters, rocks, and structures of lunar surface,
which reveals the geological processes and evolution of the Moon. This geologic map is
compiled in both Chinese and English, and will be published in hard copies by the
Geological Publishing House, and the digital version will be released as well. For further
investigation and to make the best use of the map, the geodatabases of the map will be

publicly accessible. As unprecedented integrative product of lunar exploration results, the
1:2,500,000-scale lunar geologic map will play important roles for the scientific study of the
Moon and lunar exploration in the future. With 10 years of endeavors, the experience we
learned from this lunar mapping project lays the foundation for mapping other planets.
Conflict of interest
The authors declare that they have no conflict of interest.
Acknowledgments
This work was supported by National Science and Technology Infrastructure Work
Projects (2015FY210500), the Key Research Program of Frontier Sciences, Chinese
Academy of Sciences (QYZDY-SSW-DQC028), the Strategic Priority Program of the
Chinese Academy of Sciences (XDB41000000), the National Natural Science Foundation
of China (41773065, 41941003, and 41902317), and the Natural Science Foundation of
Inner Mongolia, China (2020LH04002). We thank the cartographers including dozens of
graduate students who compiled the quadrangular maps, the editor for handling the
manuscript, and two reviewers for their comments and suggestions. The full size of the
geologic map is available at https://dx.doi.org/10.12176/03.99.02797.
Author contributions
Jianzhong Liu and Ziyuan Ouyang conceptualized this work. Jinzhu Ji and Dijun Guo
wrote the manuscript and performed the analyses. Jianzhong Liu and Dijun Guo updated
the lunar time scale scheme. Jianzhong Liu, Juntao Wang, and Jingwen Liu contributed to
mapping the crater materials and basin formations. Zongcheng Ling and Jian Chen
completed the endogenic lithologic map of lunar surface. Shenbo Chen and Kai Zhu
mapped the geologic structures of the Moon. Xiaozhong Ding and Kunying Han designed
the legend and map layout. Jianping Chen contributed to creating the geodatabase.
Weiming Cheng contributed to map pre-publish editing. All authors contributed to
discussions on many aspects of the maps.
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Jinzhu Ji is a lecturer at School of Mining, Inner Mongolia
University of Technology and visiting scholar at Center for
Lunar and Planetary Science, Institute of Geochemistry,
Chinese Academy of Sciences. His research is about lunar
geologic mapping.

Dijun Guo is an associate professor at National Space
Science Center, Chinese Academy of Sciences. His research
focuses on the evolution history and surface processes of
terrestrial planets.
Jianzhong Liu is a professor at Center for Lunar and
Planetary Science, Institute of Geochemistry, Chinese
Academy of Sciences. His research focuses on lunar and
planetary geology, especially cartography and digital
planetary models.