Stratigraphy of Lunar Craters

 

Don E. Wilhelms and Charles J. Byrne

 

January 23, 2009

 

 

 

Section

Title

Page

Introduction

 

2

Chapter 1

The Pre-Nectarian System

5

Chapter 2

The Nectarian System

14

Chapter 3

The Imbrian System, Lower Imbrian Series

30

Chapter 4

The Imbrian System, Upper Imbrian Series

33

Chapter 5

The Eratosthenian System

37

Chapter 6

The Copernican System

41

Chapter 7

Revised Strata Assignments

43

Appendix A

Lunar Craters Sorted by Name

A-1

Appendix B

Lunar Craters Sorted by LAC Chart

B-1


Introduction

 

In 1987 the U.S. Geological Survey (USGS) published what is still the most complete assessment of the ages of lunar craters, The Geologic History of the Moon (GHM; USGS Professional Paper 1348, by Don Wilhelms and two expert contributors of special sections, John F. McCauley and Newell J. Trask).  Relative ages of lunar geologic units are determined in ways that are simple in principle if often difficult in practice.  Decades of work have established that almost all lunar craters were created by impacts and started their existence looking pretty much alike: a deep bowl surrounded by a rough raised rim that in turn is surrounded by radial ejecta ridges and secondary-impact craters.  Where this pattern is complete, the crater is probably younger than adjacent units.  Where the pattern is interrupted by another crater's ejecta or a flood of mare material, the interrupting unit is the younger.  A very powerful stratigraphic technique derives from the observation that the largest lunar features, the ringed impact basins, also display consistent patterns in their extensive ejecta deposits and secondary-crater fields.  A crater superposed anywhere on these is obviously younger than the basin.  Where a crater is striated or roughened by a basin's ejecta or is pockmarked by its secondaries, that crater is older than the basin. This is an especially valuable dating tool over wide areas.  Ejecta and mare units have also been dated relative to one another by counts of superposed smaller craters.  In the absence of good stratigraphic control, ages of craters are estimated from their morphologies: with time they lose their originally sharp features and steep slopes.

 

Age relations established by these simple observations on Earth-based, Lunar Orbiter, and Apollo photographs have been mapped over the whole Moon and unified into a stratigraphic column, a classification of the succession of deposited layers.  The ejecta blankets and secondary-crater fields of the Nectaris, Imbrium, and Orientale basins supply the main reference horizons.  Six main subdivisions of this column are defined or redefined in GHM and provide the organizing framework for the present contribution. 

 

By a convention long established for Earth geology, "system" refers to all the physical deposits formed during a period of geologic time, and "series" to all those formed within the subdivisions of a period called an "epoch".  The specific systems and series defined for the Moon are:

 

The pre-Nectarian System includes all deposits that are older than the Nectaris Basin. 

The Nectarian System includes the Nectaris Basin and all other basins and craters up to but not including the Imbrium Basin.

The Lower Imbrian Series is bounded below and above by the Imbrium and Orientale basins, respectively, and also includes everything formed in between (the spelling Imbrium refers to the physical basin and Imbrian to age and stratigraphic position).

The Upper Imbrian Series includes deposits younger than Orientale but older than the mare basalts sampled by Apollo 12.

The Eratosthenian System includes those basalts and other mare- and crater materials up to a roughly estimated age of 1.1 aeons (billion years).

The Copernican System fills out the recent lunar geologic record.

 

The tables in the present document supplement and update GHM.  Ages of craters 30 km and larger in diameter are summarized in GHM on six two-part color plates, part A for the nearside and B for the farside.  Each of the six plates is devoted to one of the systems or series.  The main contribution of our document is to give the names and coordinates of the craters mapped on the plates, especially the many on the crowded pre-Nectarian and Nectarian plates that were mapped but could not be named for lack of space. For now, only the 60 km pre-Nectarians are listed in these tables because of doubts about the ages of smaller ones.  Following are the correspondences between the GHM plates and the chapters in our document:

 

GHM Plate

Chapter

System

Series

Age

 

 

 

 

 

6

1

Pre-Nectarian

 

>3.92 aeons

7

2

Nectarian

 

3.92-3.84 aeons

8

3

Imbrian

Lower Imbrian

3.84-3.8 aeons

9

4

Imbrian

Upper Imbrian

3.8-3.2 aeons

10

5

Eratosthenian

 

3.2-1.1 aeons

11

6

Copernican

 

<1.1 aeons

 

The absolute ages (an aeon is one billion years) are those accepted in GHM from calibrations of the relative stratigraphy with radiometric dates measured on samples returned from the Moon.

 

Each chapter contains two tables, one for the nearside craters and one for the farside. The "Comments"  in the last column of the tables correct some errors, state remaining uncertainties, present a few new findings, note name changes, and describe some important superposition relations between craters and basins.  The Nectarian tables, for example, contain many comments in the form  "Younger than basin X"  or  "Older than basin Y" .  These reflect the fact that the Nectarian System includes a number of basins that have been ranked stratigraphically (and potentially could subdivide the system).   "Partly covered by Imbrian ejecta" is a frequent comment as well.  These relations are portrayed on the GHM plates as follows:

 

Craters are mapped as circles, solid black if exposed.

If a crater is covered by a unit of ejecta or mare material belonging to the same system or series as the crater, its color is that of the overlying unit.

If not colored, the overlying unit belongs to a younger age category than the crater and is mapped in color on one of the higher-numbered plates.

 

Important examples are the large blank areas on both the pre-Nectarian and Nectarian plates (6 and 7, respectively), that correspond to the ejecta blankets of the Imbrium and Orientale basins; these are Lower Imbrian and thus mapped in color on Plate 8.  Nectarian basins mapped in color on Plate 7 add to the blank areas of the pre-Nectarian plate. 

 

Most positions and sizes given in our tables were originally compiled at the Lunar and Planetary Laboratory, University of Arizona, by Leif Andersson and Ewen Whitaker (NASA Catalogue of Lunar Nomenclature, NASA Reference Publication 1097, 1982).  Some comments in our tables reflect nomenclature used by NASA. Some of these names were changed or modified by subsequent actions of the International Astronomical Union (IAU).  The complete IAU list includes a very large number of names, some for craters as small  as 1 km in diameter. The  NASA  system includes lettered names of  satellitic  craters arrayed around a patronymic, an easily workable system initiated by Johann Mädler in the 19th century and developed and refined by Ewen Whitaker.  The Andersson-Whitaker positions and names have been recompiled in The Clementine Atlas of the Moon (by Ben Bussey and Paul Spudis, Cambridge University Press, 2004).  The USGS Web page (http://planetarynames.wr.usgs.gov/) also gives the positions and sizes for the named craters and the lettered ones of the catalog (a recent addition). This web site lists the lettered craters as "satellite features". It also identifies the people (mostly scientists) for whom the craters are named.  It includes the diverse diacritical marks that are important in many names but are absent from the Andersson-Whitaker and Clementine lists.  Our tables give both the current and superseded names where necessary, as clarified in the Comments column.  Some craters listed in the tables do not appear in the NASA, USGS, or Clementine lists but were found on one of the airbrushed charts published by various agencies that were used in the preparation of GHM; this is the meaning of the comment  "not in catalog".

 

The very useful Clementine atlas is conveniently organized. The Clementine images and airbrushed charts are displayed in 144 two-page sections, each based on one of the 1:1,000,000-scale charts originally planned early in the Space Age by the U.S. Air Force Aeronautical Chart and Information Center (ACIC) to cover the whole Moon.  One of the Clementine pages shows the Clementine orbital image of each Lunar Aeronautical Chart (LAC) area and the other a redrawing of the LAC, with feature names.  The Clementine gazetteer and our tables refer to the LAC on which each crater is depicted.  The LAC numbers for lettered names in the catalog and the Clementine atlas sometimes refer to the LAC on which their patronymic crater appears. These have often been changed in our tables to designate the LAC for the specific lettered crater.  In a few cases corrections have been made to the designated LAC number.

 

GHM and this contribution are progress reports.  Even now, fifty years after it was first imaged by spacecraft and after intense study by the United States and the Soviet Union, the Moon awaits good imaging over its whole surface; Mars has been better imaged.  Scientifically oriented books such as GHM contain good selections of Lunar Orbiter and Apollo photographs, but not full coverage.  Selected Lunar Orbiter photographs have recently been reprocessed and presented by Charles Byrne in two books: Lunar Orbiter Photographic Atlas of the Near Side of the Moon (Springer, 2005) and The Far Side of the Moon: A Photographic Guide (Springer, 2008).  Clementine imaging improved considerably over Lunar Orbiter at high latitudes but was degraded by high sun illumination at low latitudes.  We await better photos from the spacecraft of several countries that are now orbiting or soon to be launched.

 

In addition to the tables for each of the plates in the GHM, there is a table in Chapter 7 that lists craters whose stratagraphic assignment has been changed from that in the GHM because of new understanding, new images from Clementine, or reconsideration. Appendix A lists all of the craters documented in the main body in alphabetical order, with their coordinates, LAC charts, strata and comments; it serves as an index for the main body. Appendix B lists the craters sorted by their LAC chart numbers, so that all the craters centered in each LAC are grouped together with their strata and comments. This appendix is intended to aid in comparison of the topography of craters of different ages.


 Chapter 1. The Pre-Nectarian System

 

Table 1.1 Pre-Nectarian System, Nearside, Plate 6A

Feature

Latitude

Longitude

Diam. (km)

LAC

Comments

 

 

 

 

 

 

Abel

34.5 S

87.3 E

122

116

 

Abel M

32.2 S

83.6 E

81

116

 

Alexander

40.3 N

13.5 E

81

26

 

Amundsen A

 

 

 

144

Renamed Hêdervâri

Anaximander

66.9 N

51.3 W

67

2

 

Anaximander B

67.8 N

60.7 W

78

2

 

Anaximander D

65.4 N

50.1 W

92

2

 

Anaximenes

72.5 N

44.5 W

80

2

 

Arnold

66.8 N

35.9 E

94

4

 

Babbage

59.7 N

57.1 W

143

10

 

Babbage D

58.6 N

61.0 W

68

10

 

Baco

51.0 S

19.1 E

69

127

Probably Nectarian; should be shown on Plate 7A, not 6A

Baillaud

74.6 N

37.5 E

89

4

 

Balboa

19.1 N

83.2 W

69

37

Probably Nectarian; should be shown on Plate 7A, not 6A

Balboa B

20.3 N

82.3 W

62

37

 

Balmer

20.3 S

69.8 E

138

98

Name is on LAC 99

Barnard

29.5 S

85.6 E

105

99

Possibly Nectarian

Barrow

71.3 N

7.7 E

92

3

Possibly Nectarian

Birmingham

65.1 N

10.5 W

92

3

 

Boguslawsky

72.9 S

43.2 E

97

138

 

Boguslawsky B

73.9 S

61.0 E

63

139

 

Bohr

12.4 N

86.6 W

71

55

 

Bonpland

8.3 S

17.4 W

60

76

 

Boole

63.7 N

87.4 W

63

21

 

Boole H

61.6 N

88.9 W

75

21

 

Boussingault

70.2 S

54.6 E

142

138

 

Boussingault E

67.2 S

46.8 E

98

138

 

Brenner

39.0 S

39.3 E

97

114

 

Brianchon

75.0 N

86.2 W

134

9

 

Brisbane Z

52.8 S

72.4 E

64

129

 

Byrd

85.3 N

9.8 E

93

1

 

Casatus

72.8 S

29.5 W

108

137

 

Clairaut

47.7 S

13.9 E

75

113

 

Curtius D

64.8 S

8.1 E

61

137

 

Cuvier

50.3 S

9.9 E

75

126

 

Darwin

20.2 S

69.5 W

120

92

 

Davy Y

11.0 S

7.1 W

70

77

 

De La Rue

59.1 N

52.3 E

134

14

 

De Sitter L

78.8 N

34.5 E

69

4

 

Desargues

70.2 N

73.3 W

85

2

 

Deslandres

33.1 S

4.8 W

256

112

Name is on LAC 95

Drebbel E

38.1 S

51.3 W

65

110

 

Drygalski

79.3 S

84.9 W

149

143

 

Eddington

21.3 N

72.2 W

118

37

 

Einstein

16.3 N

88.7 W

198

37

 

Endymion J

53.5 N

50.7 E

67

14

 

Encke T

3.4 N

38.0 W

91

57

May not be a crater

Euclides P

4.5 S

27.6 W

66

76

 

Euctemon

76.4 N

31.3 E

62

4

 

Faraday

42.4 S

8.7 E

69

112

 

Fernelius

38.1 S

4.9 E

65

112

 

Flammarion

3.4 S

3.7 W

74

77

 

Flamsteed P

3.2 S

44.1 W

112

75

Possibly Nectarian

Fra Mauro

6.1 S

17.0 W

101

76

 

Fraunhofer J

42.4 S

63.6 E

63

115

 

Furnerius

36.0 S

60.6 E

135

115

 

Gärtner

59.1 N

34.6 E

115

13

 

Gauricus

33.8 S

12.6 W

79

112

 

Gemma Frisius

34.2 S

13.3 E

87

113

 

Gemma Frisius A

35.8 S

15.2 E

68

113

 

Gerard

44.5 N

80 W

90

22

 

Gilbert

3.2 S

76.0 E

112

81

 

Gill

63.9 S

75.9 E

66

129

 

Goldschmidt

73.2 N

3.8 W

113

3

 

Grimaldi

5.5 S

68.3 W

172

74

 

Gruemberger

66.9 S

10.0 W

93

137

 

Guericke

11.5 S

14.1 W

63

76

 

Hagecius

59.8 S

46.6 E

76

128

 

Hagecius A

58.2 S

47.2 E

61

128

 

Harlan

38.5 S

79.5 E

65

115

 

Hartwig

6.1 S

80.5 W

79

73

 

Hecataeus B

19.5 S

75.6 E

69

99

 

Hecataeus K

19.1 S

79.8 E

76

99

 

Hêdervâri

81.8 S

84.0 E

69

144

Formerly Amundsen A

Hedin

2.0 N

76.5 W

150

55

 

Hedin A

5.5 N

78.1 W

60

55

 

Heinsius

39.5 S

17.7 W

64

111

 

Helmholtz

68.1 S

64.1 E

94

139

 

Heraclitus

49.2 S

6.2 E

90

126

 

Hermite

86.0 N

89.9 W

104

1

 

Hipparchus

5.1 S

5.2 E

138

77

 

Hommel

54.7 S

33.8 E

126

127

 

J. Herschel

62.0 N

42.0 W

165

11

 

Jacobi

56.7 S

11.4 E

68

127

 

Janssen

13.5 N

28.7 E

23

60

 

Julius Caesar

9.0 N

15.4 E

90

60

Possibly Nectarian

Käastner

6.8 S

78.5 E

108

81

 

Kiess

6.4 S

84.0 E

63

81

 

Klaproth

69.8 S

26.0 W

119

137

 

La Caille

23.8 S

1.1 E

67

95

 

Lagalla

44.6 S

22.5 W

85

111

 

Lagrange

32.3 S

72.8 W

225

109

 

Lagrange R

31.3 S

76.5 W

130

91

Covered by Orientale Basin ejecta; may not be crater

Lamarck

22.9 S

69.8 W

100

92

 

Lamarck D

25.0 S

74.1 W

131

91

 

Lavoisier

38.2 N

81.2 W

70

22

Possibly Nectarian or younger

Le Gentil

74.6 S

75.7 W

128

136

May not be a crater

Legendre

28.9 S

70.2 E

78

99

 

Legendre K

29.8 S

72.8 E

90

99

 

Licetus

47.1 S

6.7 E

74

112

 

Longomontanus Z

50.0 S

18.7 W

95

126

 

Lyot

49.8 S

84.5 E

132

129

 

Lyot H

51.4 S

78.2 E

63

129

 

Lyot L

54.4 S

83.1 E

70

129

 

Maestlin R

3.5 N

41.5 W

61

57

 

Maginus

50.5 S

6.3 W

194

126

 

Malapert

84.9 S

12.9 E

69

144

 

Manzinus

67.7 S

26.8 E

98

138

 

Mee

43.7 S

35.3 W

126

111

 

Messala

39.2 N

60.5 E

125

28

 

Meton

73.6 N

18.8 E

130

4

 

Meton C

70.6 N

19.0 E

77

4

 

Meton D

72.2 N

24.7 E

78

4

 

Montanari

45.8 S

20.6 W

76

111

 

Mouchez

78.3 N

26.6 W

81

3

 

Murchison

5.1 N

0.1 W

57

59

 

Mutus

63.6 S

30.1 E

77

127

 

Nansen F

84.7 N

60.0 E

62

1

 

Nasmyth

50.5 S

56.2 W

76

124

 

Nearch

58.5 S

39.1 E

75

127

 

Newton A

79.7 S

19.7 W

64

137

 

Newton G

78.2 S

18.3 W

67

137

 

Nonius

34.8 S

3.8 E

69

112

 

Oenopides

57.0 N

64.1 W

67

10

 

Orontius

40.6 S

4.6 W

105

112

 

Parrot

14.5 S

3.3 E

70

77

 

Peary

88.6 N

33.0 E

73

1

 

Peirescius

46.5 S

67.6 E

61

115

 

Petermann R

75.0 N

56.7 E

115

5

 

Phillips D

25 S

70.8 E

61

99

 

Phillips W

25.3 S

72.8 E

63

99

 

Philolaus C

71.1 N

32.7 W

95

3

 

Philolaus D

73.9 N

27.8 W

91

3

 

Philolaus G

69.0 N

23.6 W

95

3

 

Piazzi

36.6 S

67.9 W

134

109

 

Pictet

43.6 S

7.4 W

62

112

 

Pictet E

41.3 S

7.7 W

70

112

 

Playfair G

24.2 S

6.7 E

94

95

 

Poncelet

75.8 N

54.1 W

69

2

 

Poncelet C

77.4 N

73.7 W

67

2

 

Pontecoulant F

57.4 S

67.7 E

60

128

 

Ptolemaeus

9.3 S

1.9 W

164

77

 

Purbach

25.5 S

2.3 W

115

95

 

Rabbi Levi

34.7 S

23.6 E

81

113

 

Rayleigh

29.3 N

89.6 E

114

45

 

Regiomontanus

28.3 S

1.0 W

108

95

 

Repsold

51.3 N

78.6 W

109

10

Possibly Nectarian

Repsold C

48.9 N

73.6 W

133

10

Possibly Nectarian

Riccioli

3.3 S

74.6 W

139

73

Possibly Nectarian

Riccius

36.9 S

26.5 E

71

113

 

Riemann

38.9 N

86.8 E

163

29

 

Rosenberger

55.4 S

43.1 E

95

128

 

Rothmann G

28.4 S

24.3 E

92

96

 

Russsell

26.5 N

75.4 W

103

37

 

Sacrobosco

23.7 S

16.7 E

98

96

 

Sasserides

39.1 S

9.3 W

90

112

 

Scheiner

60.5 S

27.5 W

110

125

Possibly Nectarian

Schickard

44.3 S

55.3 W

206

110

 

Schiller H

50.8 S

37.7 W

66

125

 

Schorr A

20.5 S

88.4 E

64

99

Should be on Plate 6A, not 7A

Schumacher

42.4 N

60.7 E

60

28

Not on Plate 6A

Scott

82.1 S

48.5 E

103

144

 

Segner

58.9 S

48.3 W

67

125

 

Short

74.6 S

7.3.0 W

70

137

 

Short B

75.5 S

5.0 W

71

137

 

Simpelius

7.03 S

15.2 E

70

138

 

Sirsalis E

8.1 S

56.5 W

72

74

 

Sirsalis Z

10.7 S

61.9 W

91

74

 

South

58.0 N

50.8 W

104

10

 

Stöfler

41.1 S

6.0 E

126

112

 

Stöfler J

42.2 S

2.4 E

76

112

 

Struve

22.4 N

77.1 W

164

37

Possibly Nectarian

Thebit P

24.0 S

5.7 W

78

95

Flooded by Mare Nubium; may not be a crater

Vega

45.4 S

63.4 E

75

115

 

Vendelinus

16.4 S

61.6 E

131

98

 

Vlacq

53.3 S

38.8 E

89

127

 

Volta

53.9 N

84.4 W

123

21

 

W. Bond

65.4 N

4.5 E

156

3

 

Walther

33.1 S

1.0 E

128

112

Not on Plate 6A (see entry in Table 2.1)

Weiss

31.8 S

19.5 W

66

94

Flooded by Mare Nubium; may not be a crater

Wichmann R

6.6 S

39.0 W

62

75

 

Wilhelm

43.4 S

20.4 W

106

111

 

Wilson

69.2 S

42.4 W

69

136

 

Wurzelbauer

33.9 S

15.9 W

88

111

 

Xenophanes

57.5 N

82.0 W

125

21

 

Young

41.5 S

50.9 E

71

114

 

Zagut

32.0 S

22.1 E

84

113

 

 

 


 

Table 1.2 Pre-Nectarian System, Farside, Plate 6B

Feature

Latitude

Longitude

Diam. (km)

LAC

Comment

 

 

 

 

 

 

Aitken C

14.0 S

175.8 E

74

86

 

Alekhin

68.2 S

131.3 W

70

142

 

Al-Khwarizmi B

9.0 N

107.4 E

62

64

 

Al-Khwarizmi G

6.9 N

107.1 E

95

64

 

Alter

18.7 N

107.5 W

64

54

 

Amici M

11.8 S

171.9 W

105

86

 

Amici U

8.7 S

175.5 W

96

86

 

Apollo

36.1 S

151.8 W

537

121

 

Artamonov

25.5 N

103.5 E

60

46

 

Artem'ev G

10.3 N

142.8 W

60

70

 

Ashbrook

81.4 S

112.5 W

156

144

 

Avicenna

39.7 N

97.2 W

74

36

 

Avogardo

63.1 N

164.9 E

139

18

 

Babcock

4.2 N

93.9 E

99

64

 

Babcock H

3.0 N

96.5 E

63

64

 

Barbier

23.8 S

157.9 E

66

103

Likely to be Nectarian: should be on Plate 7B, not 6B

Becquerel

40.7 N

129.7 E

65

30

 

Bĕcvář

2.9 S

124.5 E

67

83

 

Beijerinck

13.5 S

151.8 E

70

85

 

Berlage

63.2 S

162.8 W

92

133

 

Birkhoff

58.7 N

146.1 W

345

19

 

Birkhoff X

62.1 N

149.7 W

77

19

 

Blackett

37.5 S

116.1 W

141

122

 

Boltzmann

81.4 S

112.5 W

76

143

 

Bolyai

33.6 S

125.9 E

135

117

 

Bolyai L

36.3 S

126.2 E

73

117

 

Bragg

42.5 N

102.9 W

84

36

 

Brashear P

76.8 S

175.7 W

71

141

 

Bronk

26.1 N

134.5 W

64

52

 

Brouwer

36.2 S

126.0 W

158

122

Partly covered by Orientale ejecta, likely pre-Nectarian, possibly Nectarian: should be shown on Plate 6A, not 7A

Buisson Z

0.0 S

112.5 E

98

83

 

Cabannes

60.9 S

169.6 W

80

133

Name is on LAC 132

Cajori

47.4 S

168.8 E

70

119

 

Campbell

45.3 N

151.4 E

219

31

 

Carver M

45.0 S

126.8 E

76

117

 

Chandler

43.8 N

171.5 E

85

32

 

Chapman

50.4 N

100.7 W

71

21

 

Chappell

54.7 N

177.0 W

80

18

 

Chauvenet J

13.9 S

139.3 E

77

84

 

Chretien

45.9 S

162.9 E

88

119

 

Chretien C

44.5 S

165.3 E

63

119

 

Cockcroft

31.3 N

162.6 W

93

51

 

Comrie K

22.1 N

112.3 W

73

53

 

Comstock

21.8 N

121.5 W

72

53

 

Crommelin

68.1 S

146.9 W

94

142

 

Curie

22.9 S

91.0 E

151

100

 

Cyrano

20.5 S

157.7 E

80

103

Possibly Nectarian

Daedalus C

4.1 S

178.9 W

68

86

 

Daedalus W

3.5 S

177.5 E

70

86

 

Danjon X

10.0 S

122.8 E

65

83

 

Debye

49.6 N

176.2 W

142

18

 

Dellinger

6.8 S

140.6 E

81

84

 

Denning R

17.2 S

141.2 E

72

102

 

Deutsch

24.1 N

110.5 E

66

47

 

Duner

44.8 N

179.5 E

62

33

 

Dyson Q

59.8 N

125.7 W

89

20

 

Edison

25 N

99.1 E

62

46

 

Elvey

8.8 N

100.5 W

74

72

 

Emden

63.3 N

177.3 W

111

18

 

Engelhardt B

8.3 N

157.7 W

136

69

 

Eötvös

35.5 S

133.8 E

99

118

 

Erro

5.7 N

98.5 E

61

64

 

Esnault-Pelterie

47.7 N

141.4 W

79

34

 

Espin

28.1 N

109.1 E

75

46

 

Evans

9.5 S

133.5 W

67

88

 

Evans Q

11.2 S

136.4 W

137

88

 

Evershed

35.7 N

159.5 W

66

33

 

Fabry

42.9 N

100.7 E

184

29

 

Fermi

19.3 S

122.6 E

183

101

 

Firsov S

3.6 N

109.8 E

96

64

Name is on LAC 65

Fizeau S

58.7 S

139.9 W

62

134

 

Florensky

25.3 N

131.5 E

71

48

Formerly Vernadskiy B

Fowler

42.3 N

145.0 W

146

34

 

Fridman (Friedmann)

12.6 S

126.0W

 

89

Should be shown on Plate 6B, not 9B

Frost

37.7 N

118.4 W

75

35

Possibly Nectarian

Gagarin

20.2 S

149.2 E

265

102

 

Galois

14.2 S

151.9 W

222

87

 

Galois Q

15.2 S

154.7 W

132

87

 

Garavito

47.5 S

156.7 E

74

119

 

Gregory

2.2 N

127.2 E

67

65

 

Gregory Q

0.6 N

125.7 E

68

65

 

Guyot

11.4 N

117.5 E

92

65

 

H. G. Wells

40.7 N

122.8 E

114

30

 

Harkhebi

39.6 N

98.3 E

237

29

 

Heaviside

10.4 S

167.1 E

165

85

 

Heaviside K

13.3 S

168.5 E

110

85

 

Helberg C

23.4 N

100.6 W

70

54

 

Henyey

13.5 N

151.6 W

63

69

 

Hess

54.3 S

174.6 E

88

132

 

Hess Z

52.0 S

174.0 E

73

132

 

Hirayama

6.1 S

93.5 E

132

82

 

Houzeau

17.1 S

123.5 W

71

107

 

Ibn Firnas

6.8 N

122.3 E

89

65

 

Icarus D

4.3 S

171.2 W

68

86

 

Idel'son

81.5 S

110.9 E

60

144

 

Isaev

17.5 S

147.5 E

90

102

 

Jeans

55.8 S

91.4 E

79

129

 

Jeans N

58.7 S

90.5 E

64

129

 

Joliot

25.8 N

93.1 E

164

46

Possibly Nectarian

Joule L

26.1 N

144.1 W

69

52

 

Jules Verne

35.0 S

147.0 E

143

118

 

Keeler L

13.3 S

163.2 E

71

85

 

Kidinnu E

36.3 N

124.5 E

60

30

 

Klute

37.2 N

141.3 W

75

34

 

Koch

42.8 S

150.1 E

95

118

 

Kondratyuk

14.9 S

115.5 E

108

83

 

Kramers

53.6 N

127.6 W

61

20

 

Krylov A

38.9 N

165.1 W

63

33

 

Kugler

53.8 S

103.7 E

65

130

 

Lamb G

43.2 S

105.9 E

69

116

 

Lampland

31.0 S

131.0 E

65

102

 

Landau

41.6 N

118.1 W

214

35

 

Langemak N

12.9 S

119.0 E

126

83

 

Laue

28.0 N

96.7 W

87

54

Possibly Nectarian

Lebedev

47.3 S

107.8 E

102

117

 

Leeuwenhoek E

28.2 S

176.7 W

117

104

 

Leibnitz

38.3 S

179.2 E

245

120

 

Leucippus Q

25.9 N

118.8 W

84

53

 

Levi-Civita

23.7 S

143.4 E

121

102

 

Lippmann

56.0 S

114.9 W

160

134

 

Lodygin G

 

 

 

106

Renamed Sternfeld

Lorentz

32.6 N

95.3 W

312

36

 

Love

6.3 S

129.0 E

84

83

 

Lundmark

39.7 S

152.5 E

106

118

 

Mach

18.5 N

149.3 W

180

52

 

Mandel'shtam

5.4 N

162.4 E

197

67

 

McLaughlin

47.1 N

92.9 W

79

36

 

McLaughlin C

48.5 N

91.9 W

60

21

 

Mees Y

15.7 N

96.6 W

85

72

 

Mezentsev

72.1 N

128.7 W

89

8

 

Mezentsev M

68.7 N

126.8 W

74

8

 

Milne

31.4 S

112.2 E

272

101

 

Milne P

37.1 S

107.7 E

95

117

 

Milne Q

34.3 S

107.3 E

75

117

 

Mineur

25 N

161.3 W

73

51

 

Minkowski

56.5 S

146.0 W

113

133

 

Minnaert

67.8 S

179.6 E

125

141

 

Mitra

18.0 N

154.7 W

92

51

 

Montgolfier

47.3 N

159.8 W

88

33

 

Morozov F

5.4 N

130.0 E

60

65

 

Moseley

20.9 N

90.1 W

90

54

Named on LAC 37

Nassau D

23.7 S

179.2 W

62

104

 

Nassau F

24.7 S

179.2 E

112

104

 

Necho P

6.8 S

122.0 E

75

83

 

Nishina

44.6 S

170.4 W

65

120

 

Olivier N

56.7 N

137.1 E

63

17

 

Omar Khayyam

58.0 N

102.1 W

70

21

 

Oresme

42.4 S

169.2 E

76

119

 

Oresme U

41.6 S

164.8 E

84

119

 

Orlov Y

22.8 S

175.1 W

126

104

 

Ostwald

10.4 N

121.9 E

104

65

 

Pannekoek

4.2 S

140.5 E

71

84

 

Pannekoek R

5.4 S

138.3 E

71

84

 

Paracelsus

23.0 S

163.1 E

83

103

 

Paracelsus E

23.0 S

167.2 E

66

103

 

Paracelsus P

24.9 S

161.7 E

63

103

 

Paraskevopoulos

50.4 N

149.9 W

94

19

 

Paraskevopoulos S

49.1 N

154.9 W

67

19

 

Parenago

25.9 N

108.5 W

93

54

 

Parkhurst

33.4 S

103.6 E

96

116

 

Paschen

13.5 S

139.8 W

124

88

 

Pasteur

11.9 S

104.6 E

224

82

 

Pavlov M

32.3 S

141.8 E

74

118

 

Perepelkin

10.0 S

129.0 E

97

83

 

Planck

57.9 S

136.8 E

314

131

 

Planck Z

56.4 S

135.2 E

72

131

 

Poczobutt

57.1 N

98.8 W

195

21

 

Poincaré

56.7 S

163.6 E

319

132

 

Poinsot

79.5 N

145.7 W

68

8

 

Polzunov

25.3 N

114.6 E

67

47

 

Popov

17.2 N

99.7 E

65

46

 

Prager

3.9 S

130.5 E

60

84

 

Prager G

4.6 S

134.0 E

76

84

 

Richardson

31.1 N

100.5 E

141

46

Name is on LAC 29

Roberts

71.1 N

174.5 W

89

7

 

Röntgen

33.0 N

91.4 W

126

36

 

RozhdestvenskIy

85.2 N

155.4 W

177

1

 

RozhdestvenskIy W

84.8 N

137.2 E

75

1

 

Rumford T

28.6 S

172.1 E

108

104

 

Rynin

47.0 N

103.5 W

75

36

 

Saenger B

5.6 N

103.1 E

64

64

 

Saha C

1.4 N

107.8 E

64

64

 

Schlesinger

47.4 N

138.6 W

97

34

 

Schlesinger B

51.4 N

134.9 W

66

20

 

Seares

73.5 N

145.8 E

110

7

 

Seidel

32.8 S

152.2 E

62

118

 

Shayn

32.6 N

172.5 E

93

32

 

Shternberg

19.5 N

116.3 W

70

53

 

Sniadecki Q

23.0 S

170.1 W

77

104

 

St. John

10.2 N

150.2 E

68

67

Named on 66

Stebbins

64.8 N

141.8 W

131

8

 

Stefan

46.0 N

108.3 W

125

36

 

Sternfeld

19.6 S

141.2 W

100

106

Formerly Ladygin G

Stetson

39.6 S

118.3 W

64

122

 

Störmer C

58.3 N

150.6 E

61

17

 

Subbotin

29.2 S

135.3 E

67

102

 

Szilard

34.0 N

105.7 E

122

29

 

Teisserenc

32.2 N

135.9 W

62

34

 

Thiessen

75.4 N

169.0 W

66

8

 

Thomson

32.7 S

166.2 E

117

119

 

Thomson M

35.7 S

166.0 E

119

119

 

Tikhomirov

25.2 N

162.0 E

65

49

 

Tikhov

62.3 N

171.7 E

83

18

 

Titius

26.8 S

100.7 E

73

100

 

Tsander

6.2 N

149.3 W

181

70

 

Van der Waals

43.9 S

119.9 E

104

117

 

Van Maanen

35.7 N

128.0 E

60

30

 

Van't Hoff

62.1 N

131.8 W

92

20

 

Ventris

4.9 S

158.0 E

95

85

 

Vernadskiy B

 

 

 

48

Renamed Florensky

Vernadskiy X

25.9 N

129.0 E

64

47

 

Vertregt

19.8 S

171.1 E

187

104

 

Vestine

33.9 N

93.9 E

96

29

 

Vetchinkin

10.2 N

131.3 E

98

66

 

von Bekesy

51.9 N

126.8 E

96

16

 

Von Karman

44.8 S

175.9 E

180

119

 

Von Kármán M

47.2 S

176.2 E

225

119

Name is on LAC 132

Von Zeipel

42.6 N

141.6 W

83

34

 

Watson

62.6 S

124.5 W

62

134

 

Weyl

17.5 N

120.2 W

108

53

 

Wiener K

39.3 N

147.8 E

101

31

 

Wilsing

21.5 S

155.2 W

73

105

 

Winlock M

32.3 N

106.0 W

68

36

 

Wyld

1.4 S

98.1 E

93

82

 

Yablochkov

60.9 N

128.3 E

99

16

 

Yamamoto

58.1 N

160.9 E

76

18

 

Zhiritsky F

24.9 S

121.6 E

75

101

 

Zsigmondy S

59.7 N

106.7 W

64

21

 

Zwicky

15.4 S

168.1 E

150

85

Name is on LAC 103


Chapter 2. The Nectarian System

 

In the Nectarian System, two groups of basins help to define the system. Group 1 is relatively old: the Korolev and Moscoviense basins are within this group. If a crater judged to be in the Nectarian System is overlain by either of these basins, it may possibly be pre-Nectarian, but it is not Lower Imbrian. On the other hand, if a crater judged to be Nectarian overlies one of the basins of the younger Group 2 (Crisium, Hertzsprung, Humboldtianum, or Mendeleev), it is possibly Lower Imbriam, but is not pre-Nectarian. When a crater is partly covered by Imbrian ejecta (typically from either the Imbrium Basin or the Orientale Basin) it is difficult to judge its proper system. Of course, if it is partly covered by Imbrium ejecta it cannot be younger than Nectarian, and if partly covered by Orientale ejecta, it cannot be younger than Lower Imbriam, but still can be judged to be Nectarian.

 

Table 2.1 Nectarian System, Nearside, Plate 7A

Feature

Latitude

Longitude

Diam. (km)

LAC

Comments

 

 

 

 

 

 

Abel B

36.7 S

82.8 E

41

116

 

Abel L

34.4 S

82.6 E

67

116

Partly covered by Imbrian ejecta

Abulfeda

13.8 S

13.9 E

65

78

Partly covered by Imbrian ejecta

Adams

31.9 S

68.2 E

66

98

 

Agatharchides P

20.2 S

28.7 W

66

94

Flooded by mare

Albategnius

11.7 S

4.3 E

114

77

Partly covered by Imbrian ejecta

Aliacensis

30.6 S

5.2 E

79

95

Partly covered by Imbrian ejecta

Almanon

16.8 S

15.2 E

49

96

Partly covered by Imbrian ejecta

Alphonsus

13.7 S

3.2 W

108

77

Partly covered by Imbrian ejecta

Amundsen

84.3 S

85.6 E

101

144

 

Ansgarius

12.7 S

79.7 E

94

81

Younger than  Crisium Basin

Apianus

26.9 S

7.9 E

63

95

Partly covered by Imbrian ejecta

Apollonius

4.5 N

61.1 E

53

62

Younger than Crisium Basin

Aston

32.9 N

87.7 W

43

36

Partly covered by Imbrian ejecta

Azophi

22.1 S

12.7 E

47

96

Partly covered by Imbrian ejecta

Baco

51.0 S

19.1 E

69

127

Possibly Pre-Nectarian

Baco A

52.8 S

20.2 E

39

127

 

Baco B

49.5 S

16.6 E

43

127

 

Bailly

66.5 S

69.1 W

287

136

Partly covered by Imbrian ejecta

Bailly A

69.3 S

59.5 W

38

136

 

Bailly B

68.8 S

63.1 W

65

136

 

Balboa

19.1 N

83.2 W

69

37

Partly covered by Imbrian ejecta, possibly pre-Nectarian

Ball

35.9 S

8.4 W

41

112

Possibly  Lower Imbrian

Ball C

37.7 S

8.7 W

31

112

 

Barocius B

44.0 S

18.3 E

39

113

 

Bartels

24.5 N

89.8 W

55

37

Partly covered by Imbrian ejecta

Bayer

51.6 S

35.0 W

47

125

 

Beaumont

18.0 S

28.8 E

53

96

 

Behaim

16.5 S

79.4 E

55

99

 

Bel'kovich A

58.7 N

86.0 E

58

15

Younger than Humboldtianum Basin

Berosus

33.5 N

69.9 E

74

28

Partly covered by Imbrian ejecta, younger than Crisium Basin

Berzelius

36.6 N

50.9 E

50

27

Older than Crisium Basin

Biela

54.9 S

51.3 E

76

128

 

Biela B

56.5 S

49.6 E

43

128

 

Billy

13.8 S

50.1 W

45

74

Partly covered by Orientale ejecta; possibly Lower Imbrian

Blancanus

63.8 S

21.4 W

117

125

 

Blancanus C

66.5 S

28.0 W

46

137

 

Bohnenberger A

17.8 S

40.1 E

30

97

 

Borda

25.1 S

46.6 E

44

97

 

Boss L

50.9 N

82.3 E

40

15

Younger than Humboldtianum Basin

Boussingault A

69.9 S

54.0 E

72

138

 

Brenner A

40.4 S

40.0 E

32

114

 

Burckhardt E

30.6 N

55.7 E

39

44

Younger than Crisium Basin

Byrgius

24.7 S

65.3 W

87

92

Partly covered by Imbrian ejecta

C. Mayer B

60.2 N

15.6 E

36

13

Partly covered by Imbrian ejecta

Cabeus B

82.4 S

53.0 W

61

144

 

Cannon

19.9 N

81.4 E

56

45

Older than Crisium Basin, possibly pre-Nectarian

Capella

7.5 S

35.0 E

49

79

 

Capuanus

34.1 S

26.7 W

59

111

Partly covered by Imbrian ejecta

Catharina

18.1 S

23.4 E

104

96

 

Cavendish

24.5 S

53.7 W

56

92

Partly covered by Imbrian ejecta

Censorinus N

1.9 S

36.5 E

36

79

 

Clavius

58.8 S

14.1 W

245

126

 

Cleomedes

27.7 N

56.0 E

125

44

Younger than Crisium Basin

Cleostratus

60.4 N

77.0 W

62

10

Partly covered by Imbrian ejecta

Cleostratus F

61.5 N

80.4 W

50

21

Partly covered by Imbrian ejecta

Colombo

15.1 S

45.8 E

76

79

 

Colombo A

14.1 S

44.4 E

42

79

 

Condorcet

12.1 N

69.6 E

74

62

Younger than Crisium Basin

Condorcet F

8.2 N

73.1 E

37

63

Younger than Crisium Basin

Condorcet P

8.7 N

70.4 E

46

63

Younger than Crisium Basin

Cook

17.5 S

48.9 E

46

97

 

Curtius

67.2 S

4.4 E

95

137

 

Curtius B

63.7 S

4.7 E

41

126

 

Cusanus

72.0 N

70.8 E

63

5

Younger than Humboldtianum Basin

Cyrillus

13.2 S

24.0 E

98

78

 

Cysatus

66.2 S

6.1 W

48

137

 

de Gasparis

25.9 S

50.7 W

30

92

Partly covered by Imbrian ejecta

De Sitter

80.1 N

39.6 E

64

1

 

De Sitter A

80.2 N

26.6 E

36

1

 

De Sitter M

81.3 N

38.5 E

81

1

 

De Vico T

18.7 S

61.8 W

41

92

Partly covered by Imbrian ejecta

Debes

29.5 N

51.7 E

30

44

Younger than Crisium Basin

Debes A

28.8 N

51.5 E

33

44

Younger than Crisium Basin

Deluc

55.0 S

2.8 W

46

126

 

Demonax

77.9 S

60.8 E

128

139

 

Descartes

11.7 S

15.7 E

48

78

Partly covered by Imbrian ejecta

Doppelmayer

28.5 S

41.4 W

63

93

 

Drebbel

40.9 S

49.0 W

30

110

Partly covered by Orientale ejecta, possibly  Lower Imbrian

Dubyago

4.4 N

70.0 E

51

62

 

Eimmart

24.0 N

64.8 E

46

44

Younger than Crisium Basin

Endymion

53.9 N

57.0 E

123

14

Younger than Humboldtianum Basin

Endymion B

59.8 N

67.2 E

59

14

Younger than Humboldtianum Basin

Epigenes

67.5 N

4.6 W

55

3

Partly covered by Imbrian ejecta

Fermat

22.6 S

19.8 E

38

96

 

Firmicus

7.3 N

63.4 E

56

62

Younger than Crisium Basin

Fourier

30.3 S

53.0 W

51

92

Possibly  Lower Imbrian

Fourier A

30.2 S

49.5 W

32

93

 

Fracastorius

21.5 S

33.2 E

112

97

 

Fraunhofer C

42.9 S

64.7 E

38

115

 

Furnerius Q

39.5 S

67.3 E

30

115

 

Galvani

49.6 N

84.6 W

80

21