1217:; Fouchet, T.; Merchiorri, R.; Belluci, G.; Altieri, F.; Formisano, V.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Fonti, S.; Korablev, O.; Kottsov, V.; Ignatiev, N.; Moroz, V.; Titov, D.; Zasova, L.; Loiseau, D.; Mangold, N.; Pinet, P.; Doute, S.; Schmitt, B.; Sotin, C.; Hauber, E.; Hoffmann, H.; Jaumann, R.; Keller, U.; Arvidson, R.; Mustard, J. F.; Duxbury, T.; Forget, F.; Neukum, G. (2006). "Global Mineralogical and Aqueous Mars History Derived from OMEGA/Mars Express Data".
744:
436:
420:
765:
867:
2891:
73:
2930:
2903:
446:, a principle that lets geologists determine the relative ages of surface units. The dark-toned lava flow overlies (is younger than) the light-toned, more heavily cratered terrain at right. The ejecta of the crater at center overlies both units, indicating that the crater is the youngest feature in the image. (See cross section, above right.)
805:
or locations on the planet where surface units indicate a distinctive geological episode, recognizable in time by cratering age and stratigraphic position. For example, Hesperia Planum is the referent location for the Lower
Hesperian Series. The corresponding geologic time (geochronological) units of
789:
The
Hesperian's upper boundary is more complex and has been redefined several times based on increasingly detailed geologic mapping. Currently, the stratigraphic boundary of the Hesperian with the younger Amazonian System is defined as the base of the Vastitas Borealis Formation (pictured right). The
857:
The Earth-based scheme of rigid stratigraphic nomenclature has been successfully applied to Mars for several decades now but has numerous flaws. The scheme will no doubt become refined or replaced as more and better data become available. (See mineralogical timeline below as example of alternative.)
793:
is a vast, low-lying plain that covers much of the northern hemisphere of Mars. It is generally interpreted to consist of reworked sediments originating from the Late
Hesperian outflow channels and may be the remnant of an ocean that covered the northern lowland basins. Another interpretation of the
933:
or a late cataclysmic pulse that followed a more quiescent period of impact activity. Nevertheless, at the beginning of the
Hesperian, the impact rate had probably declined to about 80 times greater than present rates, and by the end of the Hesperian, some 700 million years later, the rate began to
788:
The lower boundary of the
Hesperian System is defined as the base of the ridged plains, which are typified by Hesperia Planum and cover about a third of the planet's surface. In eastern Hesperia Planum, the ridged plains overlie early to mid Noachian aged cratered plateau materials (pictured left).
810:. An epoch is a subdivision of a period; the two terms are not synonymous in formal stratigraphy. The age of the Early Hepserian/Late Hesperian boundary is uncertain, ranging from 3600 to 3200 million years ago based on crater counts. The average of the range is shown in the timeline below.
388:) that erupted from fissures. The number-density of large impact craters is moderate, with about 125–200 craters greater than 5 km in diameter per million km. Hesperian-aged ridged plains cover roughly 30% of the Martian surface; they are most prominent in Hesperia Planum,
1212:
Bibring, J.-P.; Langevin, Y.; Mustard, J. F.; Poulet, F.; Arvidson, R.; Gendrin, A.; Gondet, B.; Mangold, N.; Pinet, P.; Forget, F.; Berthe, M.; Bibring, J.-P.; Gendrin, A.; Gomez, C.; Gondet, B.; Jouglet, D.; Poulet, F.; Soufflot, A.; Vincendon, M.; Combes, M.; Drossart, P.;
1259:
Head, J.W.; Wilson, L. (2011). The
Noachian-Hesperian Transition on Mars: Geological Evidence for a Punctuated Phase of Global Volcanism as a Key Driver in Climate and Atmospheric Evolution. 42nd Lunar and Planetary Science Conference (2011), Abstract #1214.
710:
System are absent throughout much of the eastern central interior of the United States. However, the time interval of the
Cretaceous (Cretaceous Period) still occurred there. Thus, a geologic period represents the time interval over which the
747:
Geologic contact of
Noachian and Hesperian Systems. Hesperian ridged plains (Hr) embay and overlie older Noachian cratered plateau materials (Npl). The ridged plains partially bury many of the old Noachian-aged craters. Image is
489:) representing a sheetlike, wedgelike, or tabular body of rock that underlies the surface. A surface unit may be a crater ejecta deposit, lava flow, or any surface that can be represented in three dimensions as a discrete
921:. The Hesperian was thus a time period of rapidly declining impact cratering rates. However, the timing and rate of the decline are uncertain. The lunar cratering record suggests that the rate of impacts in the inner
909:, which became widespread as the planet grew increasingly arid. The Hesperian Period was also a time when the earliest evidence of glacial activity and ice-related processes appears in the Martian geologic record.
216:). The end of the Hesperian Period is much more uncertain and could range anywhere from 3200 to 2000 Mya, with 3000 Mya being frequently cited. The Hesperian Period is roughly coincident with the Earth's early
1668:
Catling, D.C.; Leovy, C.B.; Wood, S.E.; Day, M.D. (2011). A Lava Sea in the
Northern Plains of Mars: Circumpolar Hesperian Oceans Reconsidered. 42nd Lunar and Planetary Science Conference, Abstract #2529.
735:
of crater formation over time. Accordingly, the beginning and end dates for
Martian periods are uncertain, especially for the Hesperian/Amazonian boundary, which may be in error by a factor of 2 or 3.
877:. The small impact craters date back to the Hesperian Period and appear crisp despite their great age. This image indicates that erosion on Mars has been very slow since the end of the
1402:(1980). Definition and Characterization of Mars Global Surface Units: Preliminary Unit Maps. 11th Lunar and Planetary Science Conference: Houston: TX, abstract #1249, pp. 697–699.
196:
across the surface. The Hesperian is an intermediate and transitional period of Martian history. During the Hesperian, Mars changed from the wetter and perhaps warmer world of the
823:
Stratigraphic terms are typically confusing to geologists and non-geologists alike. One way to sort through the difficulty is by the following example: One could easily go to
679:
are not interchangeable terms in formal stratigraphic nomenclature, although they are frequently confused in popular literature. A system is an idealized stratigraphic
706:) analogous to missing pages from a book. In some places, rocks from the system are absent entirely due to nondeposition or later erosion. For example, rocks of the
1646:
Tanaka, K.L.; Skinner, J.A.; Hare, T.M. (2005). Geologic Map of the Northern Plains of Mars. Scientific Investigations Map 2888, Pamphlet; U.S. Geological Survey.
905:
formed during the Hesperian as a result of these stresses. Sulfuric-acid weathering at the surface produced an abundance of sulfate minerals that precipitated in
525:) equivalent of the Hesperian System is the Hesperian Period. Rock or surface units of the Hesperian System were formed or deposited during the Hesperian Period.
1377:
Scott, D.H.; Tanaka, K.L. (1986). Geologic Map of the Western Equatorial Region of Mars. U.S. Geological Survey Miscellaneous Investigations Series Map I–1802–A.
1655:
The Vastitas Borealis Formation is used here to include the Lower Amazonian Scandia, Vastitas Borealis interior, and Vastitas Borealis marginal units of Tanaka
1389:
Greeley, R.; Guest, J.E. (1987). Geologic Map of the Eastern Equatorial Region of Mars. U.S. Geological Survey Miscellaneous Investigations Series Map I–1802–B.
815:
404:
305:
overlying a deeper zone of liquid water. Subsequent volcanic or tectonic activity occasionally fractured the cryosphere, releasing enormous quantities of deep
885:
The Hesperian was a time of declining rates of impact cratering, intense and widespread volcanic activity, and catastrophic flooding. Many of the major
1725:
Tanaka, K.L. (2001). The Stratigraphy of Mars: What We Know, Don't Know, and Need to Do. 32nd Lunar and Planetary Science Conference, Abstract #1695.
1518:
929:(4000 million years ago) was 500 times higher than today. Planetary scientists still debate whether these high rates represent the tail end of
858:
Obtaining radiometric ages on samples from identified surface units is clearly necessary for a more complete understanding of Martian chronology.
2221:
2360:
2345:
1855:
1836:
1590:
521:, Hesperian, and Amazonian. Geologic units lying below (older than) the Noachian are informally designated Pre-Noachian. The geologic time (
2950:
2076:
313:. Much of this water flowed into the northern hemisphere where it probably pooled to form large transient lakes or an ice covered ocean.
2574:
2161:
2819:
2814:
696:
2443:
1899:
1876:
1756:
1556:
466:
property, or set of landforms that distinguish it from other surface units and is large enough to be shown on a map. Mappers use a
715:
of a system were deposited, including any unknown amounts of time present in gaps. Periods are measured in years, determined by
2096:
749:
1569:
Masson, P.; Carr, M.H.; Costard, F.; Greeley, R.; Hauber, E.; Jaumann, R. (2001). "Geomorphologic Evidence for Liquid Water".
2136:
1973:
1930:
687:(type section) correlated with rocks sections from many different locations planetwide. A system is bound above and below by
402:
1351:
Scott, D.H.; Carr, M.H. (1978). Geologic Map of Mars. U.S. Geological Survey Miscellaneous Investigations Series Map I-1083.
92:
terrain, indicating a younger age. Colors indicate elevation, with red highest, yellow intermediate, and green/blue lowest.
463:
2920:
293:
By the beginning of the Late Hesperian the atmosphere had probably thinned to its present density. As the planet cooled,
2549:
781:
77:
2779:
2534:
2529:
2438:
2046:
498:
2711:
2544:
2415:
2301:
2188:
1608:"Alba Patera, Mars: Topography, structure, and evolution of a unique late Hesperian–early Amazonian shield volcano"
502:
408:
121:
2955:
2831:
2646:
2338:
2156:
400:
344:
338:
20:
2749:
2741:
2318:
917:
As originally conceived, the Hesperian System referred to the oldest surfaces on Mars that postdate the end of
486:
509:
sequence from oldest to youngest. Units of similar age are grouped globally into larger, time-stratigraphic (
2131:
1988:
684:
334:
85:
2521:
2496:
2333:
2236:
2178:
2151:
2110:
1998:
918:
205:
1214:
2716:
2696:
2569:
2380:
2328:
2323:
2306:
2183:
2168:
798:
695:) that indicate dramatic (often abrupt) changes in the dominant fauna or environmental conditions. (See
626:
611:
514:
177:
154:
88:
for the Hesperian System. Note that Hesperia Planum has fewer large impact craters than the surrounding
2731:
2726:
2513:
1796:
1692:
1619:
1492:
1321:
1286:
1226:
1186:
1148:
1113:
1065:
1025:
977:
732:
641:
494:
443:
428:
743:
401:
2934:
2907:
2863:
2676:
2286:
2266:
2231:
1983:
1174:
930:
550:
471:
389:
189:
474:. Although based on surface characteristics, a surface unit is not the surface itself or group of
2604:
2313:
2226:
2216:
1965:
1923:
1708:
1081:
720:
716:
565:
510:
423:
Schematic cross section of image at left. Surface units are interpreted as a sequence of layers (
181:
1104:
Hartmann, W. K. (2005). "Martian cratering 8: Isochron refinement and the chronology of Mars".
2836:
2773:
2624:
2614:
2501:
2479:
2457:
2395:
2385:
2370:
2296:
2281:
2246:
2241:
2086:
2081:
1895:
1872:
1851:
1832:
1752:
1586:
1552:
1242:
790:
764:
435:
278:. Liquid water became more localized in extent and turned more acidic as it interacted with SO
232:
144:
1312:
Clifford, S. M. (1993). "A model for the hydrologic and climatic behavior of water on Mars".
2841:
2766:
2423:
2405:
2350:
2261:
2173:
1804:
1700:
1627:
1578:
1500:
1329:
1294:
1234:
1194:
1156:
1121:
1073:
1033:
985:
981:
902:
824:
616:
252:
193:
61:
1504:
2873:
2826:
2484:
2375:
2271:
2256:
2251:
2203:
2193:
2146:
2141:
2051:
2036:
2011:
1978:
1948:
894:
874:
866:
807:
680:
631:
518:
506:
482:
330:
326:
310:
204:
of the Hesperian Period is uncertain. The beginning of the period followed the end of the
197:
164:
89:
81:
1726:
1670:
1403:
1261:
1800:
1696:
1623:
1496:
1325:
1290:
1230:
1190:
1152:
1117:
1069:
1029:
2784:
2106:
2061:
2016:
1787:
Fassett, C. I.; Head, J. W. (2011). "Sequence and timing of conditions on early Mars".
870:
753:
661:
455:
264:
244:
236:
1056:
Hartmann, W. K.; Neukum, G. (2001). "Cratering Chronology and the Evolution of Mars".
19:
This article is about the Mars geologic system and time period. For other senses, see
2944:
2894:
2662:
2491:
2474:
2466:
2400:
2355:
2276:
2211:
2126:
2041:
2031:
2021:
1916:
1866:
1826:
1712:
1522:
1360:
Strom, R.G.; Croft, S.K.; Barlow, N.G. (1992) The Martian Impact Cratering Record in
898:
646:
601:
586:
571:
522:
493:
bound above or below by adjacent units (illustrated right). Using principles such as
377:
287:
2853:
2848:
2789:
2721:
2701:
2365:
2121:
2066:
2006:
1085:
922:
728:
703:
692:
467:
451:
385:
240:
228:
209:
201:
1683:
Masson, P. L. (1991). "The Martian stratigraphy — Short review and perspectives".
419:
1808:
1582:
1198:
1125:
731:
on Mars are determined by impact crater density, which is heavily dependent upon
2598:
2593:
2056:
1888:
1453:
R. Greeley, R.M. Batson, Eds.; Cambridge University Press: Cambridge UK, p. 214.
381:
306:
294:
989:
2706:
2691:
2026:
1956:
1432:
Princeton University Press: Princeton, NJ, 324 pp. and Wilhelms, D.E. (1987).
1077:
832:
724:
707:
656:
373:
302:
275:
260:
72:
359:
346:
2858:
2794:
2291:
1238:
1160:
1037:
906:
886:
843:
769:
224:
1246:
901:) throughout the western hemisphere. The huge equatorial canyon system of
702:
At any location, rock sections in a given system are apt to contain gaps (
392:, Lunae Planum, Malea Planum, and the Syria-Solis-Sinai Plana in southern
2868:
2580:
2561:
2433:
1632:
1607:
1277:
Barlow, N. G. (2010). "What we know about Mars from its impact craters".
926:
878:
581:
475:
298:
51:
46:
427:), with the youngest at top and oldest at bottom in accordance with the
2390:
2071:
1868:
A Traveler's Guide to Mars: The Mysterious Landscapes of the Red Planet
1704:
893:
stressed the crust to produce a vast network of extensional fractures (
890:
828:
784:
topographic map adapted from Ivanov and Head (2006), Figs. 1, 3, and 8.
712:
688:
596:
561:
490:
470:
approach pioneered in the early 1960s for photogeologic studies of the
424:
393:
272:
217:
42:(upper bound uncertain – between about 3200 and 2000 million years ago)
1462:
Tanaka, K.L.; Scott, D.H.; Greeley, R. (1992). Global Stratigraphy in
1333:
227:
became the primary geologic process on Mars, producing vast plains of
2116:
1298:
459:
439:
1013:
965:
806:
the two Hesperian series are the Early Hesperian and Late Hesperian
384:. These "ridged plains" are interpreted to be basaltic lava flows (
243:, had begun to form. Volcanic outgassing released large amounts of
881:. Image is 17 km across and based on Carr, 1996, p. 134, Fig. 6-8.
865:
763:
742:
434:
418:
1483:
Nimmo, F.; Tanaka, K. (2005). "Early Crustal Evolution of Mars".
1939:
889:
features on Mars formed at this time. The weight of the immense
797:
The Hesperian System is subdivided into two chronostratigraphic
768:
Approximate geologic contact of Upper Hesperian lava apron from
268:
185:
37:
1912:
1437:
801:: Lower Hesperian and Upper Hesperian. The series are based on
794:
Vastitas Borealis Formation is that it consists of lava flows.
813:
458:. A surface unit is a terrain with a distinct texture, color,
399:
223:
With the decline of heavy impacts at the end of the Noachian,
213:
691:
with distinctly different characteristics (on Earth, usually
259:
S) into the atmosphere, causing a transition in the style of
1890:
Mapping Mars: Science, Imagination, and the Birth of a World
1177:(2009). "The global martian volcanic evolutionary history".
1470:
Eds.; University of Arizona Press: Tucson, AZ, pp. 345–382.
1368:
Eds.; University of Arizona Press: Tucson, AZ, pp. 383–423.
719:. On Mars, radiometric ages are not available except from
1419:
2nd ed.; Chapman & Hall: New York, p. 8 and Fig. 1.6.
666:
smaller than an age/stage; not used by the ICS timescale
329:, a moderately cratered highland region northeast of the
1139:
Greeley, R.; Spudis, P. D. (1981). "Volcanism on Mars".
846:
there. However, you could not visit the Late Ordovician
517:. For Mars, four systems are defined: the Pre-Noachian,
1908:
542:
538:
1727:
http://www.lpi.usra.edu/meetings/lpsc2001/pdf/1695.pdf
1671:
http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2529.pdf
1404:
http://www.lpi.usra.edu/meetings/lpsc1980/pdf/1249.pdf
1262:
http://www.lpi.usra.edu/meetings/lpsc2011/pdf/1214.pdf
2918:
776:) with Lower Amazonian Vastitas Borealis Formation (A
1543:
1541:
2807:
2758:
2740:
2684:
2675:
2655:
2639:
2560:
2512:
2465:
2456:
2414:
2202:
2095:
1997:
1964:
1955:
208:and probably corresponds to the start of the lunar
200:to the dry, cold, and dusty planet seen today. The
160:
150:
140:
135:
127:
117:
112:
102:
97:
28:
1887:
1551:Prentice-Hall: Englewood Cliffs, NJ, pp 143–146,
1385:
1383:
1478:
1476:
1051:
1049:
1047:
727:and stratigraphic context are unknown. Instead,
1347:
1345:
1343:
505:to age, geologists can place the units into a
192:and catastrophic flooding that carved immense
1924:
1850:. Cambridge, UK: Cambridge University Press.
1751:Oxford University Press: Oxford, UK, 229 pp,
1485:Annual Review of Earth and Planetary Sciences
551:Units in Earth geochronology and stratigraphy
8:
1099:
1097:
1095:
959:
957:
955:
409:Martian Time Periods (Millions of Years Ago)
1831:. Old Saybrook, CT: Konecky & Konecky.
1449:Wilhelms, D.E. (1990). Geologic Mapping in
1272:
1270:
2681:
2462:
1961:
1931:
1917:
1909:
1430:Geology of the Moon: A Stratigraphic View;
1007:
1005:
1003:
1001:
999:
897:) and compressive deformational features (
1631:
1519:International Commission on Stratigraphy
819:Hesperian Epochs (Millions of Years Ago)
532:
235:). By Hesperian times, all of the large
2925:
942:
683:based on the physical rock record of a
212:period, around 3700 million years ago (
1547:Eicher, D.L.; McAlester, A.L. (1980).
1505:10.1146/annurev.earth.33.092203.122637
1279:Geological Society of America Bulletin
25:
415:Hesperian chronology and stratigraphy
7:
1819:Bibliography and recommended reading
1606:Ivanov, M. A.; Head, J. W. (2006).
1523:"International Stratigraphic Chart"
970:Earth and Planetary Science Letters
301:) began to freeze, forming a thick
873:view of Hesperian-aged surface in
636:8 total; 10 to 10 years in length
621:3 total; 10 to 10 years in length
450:Martian time periods are based on
372:. The region consists of rolling,
337:of the Hesperian System is in the
14:
1573:. Space Sciences Series of ISSI.
1434:The Geologic History of the Moon,
964:Carr, M. H.; Head, J. W. (2010).
854:and collect an actual trilobite.
325:System and Period is named after
2928:
2901:
2890:
2889:
862:Mars during the Hesperian Period
842:You could even collect a fossil
309:to the surface and carving huge
71:
1612:Journal of Geophysical Research
1314:Journal of Geophysical Research
1018:Journal of Geophysical Research
297:stored in the upper crust (mega
231:and broad volcanic constructs (
1436:USGS Professional Paper 1348;
1:
1865:Hartmann, William K. (2003).
697:Cretaceous–Paleogene boundary
16:Era of Mars' geologic history
2346:Recurring slope lineae (RSL)
1828:The Smithsonian Book of Mars
1809:10.1016/j.icarus.2010.11.014
1583:10.1007/978-94-017-1035-0_12
1438:http://ser.sese.asu.edu/GHM/
1199:10.1016/j.icarus.2008.12.019
1126:10.1016/j.icarus.2004.11.023
752:IR mosaic, based on similar
188:characterized by widespread
2951:Geologic time scale of Mars
2780:Inspiration Mars Foundation
739:Boundaries and subdivisions
499:cross-cutting relationships
317:Description and name origin
2974:
2815:Artificial objects on Mars
1440:for reviews of this topic.
1014:"The stratigraphy of Mars"
990:10.1016/j.epsl.2009.06.042
966:"Geologic history of Mars"
949:Hartmann, 2003, pp. 33–34.
934:resemble that seen today.
501:, and the relationship of
131:Martian Geologic Timescale
18:
2884:
2832:List of films set on Mars
2647:C/2013 A1 (Siding Spring)
2444:Classical albedo features
1946:
1846:Carr, Michael H. (2006).
1825:Boyce, Joseph M. (2008).
535:
339:Mare Tyrrhenum quadrangle
70:
33:
2750:List of missions to Mars
1428:See Mutch, T.A. (1970).
760:(1992), Fig. 1a, p. 352.
380:resembling those on the
80:colorized relief map of
2908:Solar System portal
1886:Morton, Oliver (2003).
1239:10.1126/science.1122659
1161:10.1029/RG019i001p00013
1078:10.1023/A:1011945222010
1038:10.1029/JB091iB13p0E139
982:2010E&PSL.294..185C
907:evaporitic environments
2522:Solar eclipses on Mars
2381:"Swiss cheese" feature
2237:Concentric crater fill
1012:Tanaka, K. L. (1986).
882:
785:
761:
756:photo shown in Tanaka
454:of surface units from
447:
432:
206:Late Heavy Bombardment
1894:. New York: Picador.
1871:. New York: Workman.
1685:Space Science Reviews
1571:Space Science Reviews
1549:History of the Earth;
1417:Planetary Landscapes,
1141:Reviews of Geophysics
1058:Space Science Reviews
869:
767:
746:
503:impact crater density
438:
422:
376:plains with abundant
2722:Permanent settlement
1633:10.1029/2005JE002469
938:Notes and references
497:(illustrated left),
429:law of superposition
2864:Timekeeping on Mars
2541:Planetary transits
2526:Satellite transits
2439:Observation history
2287:Lobate debris apron
1848:The Surface of Mars
1801:2011Icar..211.1204F
1747:Carr, M.H. (1996).
1697:1991SSRv...56....9M
1624:2006JGRE..111.9003I
1497:2005AREPS..33..133N
1415:Greeley, R. (1994)
1326:1993JGR....9810973C
1320:(E6): 10973–11016.
1291:2010GSAB..122..644B
1231:2006Sci...312..400B
1191:2009Icar..201...44W
1153:1981RvGSP..19...13G
1118:2005Icar..174..294H
1070:2001SSRv...96..165H
1030:1986LPSC...17..139T
931:planetary accretion
570:Periods of time in
511:chronostratigraphic
442:image illustrating
390:Syrtis Major Planum
356: /
239:on Mars, including
1777:Carr, 2006, p. 23.
1768:Carr, 2006, p. 15.
1738:Carr, 2006, p. 41.
1705:10.1007/BF00178385
1451:Planetary Mapping,
1024:(B13): E139–E158.
883:
850:in the Ordovician
838:of the Ordovician
786:
762:
721:Martian meteorites
717:radioactive dating
651:not used for Mars
606:not used for Mars
591:not used for Mars
566:chronostratigraphy
560:Segments of rock (
448:
433:
151:Stratigraphic unit
141:Chronological unit
128:Time scale(s) used
2916:
2915:
2869:Sol (day on Mars)
2837:Martian scientist
2820:Memorials on Mars
2803:
2802:
2774:The Case for Mars
2671:
2670:
2452:
2451:
2386:Terrain softening
2351:Ring mold craters
2319:North Polar Basin
2242:Dark slope streak
2087:Vastitas Borealis
1984:Dust devil tracks
1857:978-0-521-87201-0
1838:978-1-58834-074-0
1592:978-90-481-5725-9
1334:10.1029/93JE00225
1225:(5772): 400–404.
919:heavy bombardment
827:and visit a rock
820:
791:Vastitas Borealis
670:
669:
529:System vs. period
456:spacecraft images
411:
190:volcanic activity
170:
169:
113:Usage information
2963:
2956:Geological units
2933:
2932:
2931:
2924:
2906:
2905:
2904:
2893:
2892:
2767:The Mars Project
2682:
2630:
2620:
2610:
2588:
2586:
2585:
2463:
2324:Ocean hypothesis
2174:Outflow channels
1962:
1933:
1926:
1919:
1910:
1905:
1893:
1882:
1861:
1842:
1813:
1812:
1795:(2): 1204–1214.
1784:
1778:
1775:
1769:
1766:
1760:
1745:
1739:
1736:
1730:
1723:
1717:
1716:
1680:
1674:
1666:
1660:
1653:
1647:
1644:
1638:
1637:
1635:
1603:
1597:
1596:
1566:
1560:
1545:
1536:
1535:
1533:
1532:
1527:
1515:
1509:
1508:
1480:
1471:
1460:
1454:
1447:
1441:
1426:
1420:
1413:
1407:
1396:
1390:
1387:
1378:
1375:
1369:
1358:
1352:
1349:
1338:
1337:
1309:
1303:
1302:
1299:10.1130/B30182.1
1285:(5–6): 644–657.
1274:
1265:
1257:
1251:
1250:
1209:
1203:
1202:
1171:
1165:
1164:
1136:
1130:
1129:
1101:
1090:
1089:
1053:
1042:
1041:
1009:
994:
993:
976:(3–4): 185–203.
961:
950:
947:
913:Impact cratering
903:Valles Marineris
825:Cincinnati, Ohio
818:
546:
545:
533:
513:) units, called
495:superpositioning
452:geologic mapping
444:superpositioning
407:
371:
370:
368:
367:
366:
361:
357:
354:
353:
352:
349:
311:outflow channels
263:from dominantly
253:hydrogen sulfide
237:shield volcanoes
233:highland paterae
194:outflow channels
75:
43:
40:
26:
2973:
2972:
2966:
2965:
2964:
2962:
2961:
2960:
2941:
2940:
2939:
2929:
2927:
2919:
2917:
2912:
2902:
2900:
2880:
2874:Darian calendar
2799:
2754:
2736:
2667:
2651:
2635:
2628:
2623:
2618:
2613:
2608:
2603:
2583:
2582:
2579:
2556:
2508:
2502:Voltaire crater
2480:Stickney crater
2448:
2410:
2252:Fretted terrain
2198:
2098:
2091:
2052:Sinus Meridiani
2037:Planum Australe
2012:Cerberus (Mars)
1993:
1951:
1949:Outline of Mars
1942:
1937:
1902:
1885:
1879:
1864:
1858:
1845:
1839:
1824:
1821:
1816:
1786:
1785:
1781:
1776:
1772:
1767:
1763:
1746:
1742:
1737:
1733:
1724:
1720:
1682:
1681:
1677:
1667:
1663:
1654:
1650:
1645:
1641:
1605:
1604:
1600:
1593:
1568:
1567:
1563:
1546:
1539:
1530:
1528:
1525:
1517:
1516:
1512:
1482:
1481:
1474:
1461:
1457:
1448:
1444:
1427:
1423:
1414:
1410:
1397:
1393:
1388:
1381:
1376:
1372:
1359:
1355:
1350:
1341:
1311:
1310:
1306:
1276:
1275:
1268:
1258:
1254:
1211:
1210:
1206:
1173:
1172:
1168:
1138:
1137:
1133:
1103:
1102:
1093:
1055:
1054:
1045:
1011:
1010:
997:
963:
962:
953:
948:
944:
940:
915:
875:Terra Meridiani
864:
821:
816:
814:
779:
775:
741:
555:
554:
537:
536:
531:
417:
412:
405:
403:
364:
362:
358:
355:
350:
347:
345:
343:
342:
341:(MC-22) around
327:Hesperia Planum
319:
285:
281:
258:
250:
178:geologic system
165:Hesperia Planum
107:
93:
82:Hesperia Planum
66:
65:
64:
59:
54:
49:
41:
35:
24:
17:
12:
11:
5:
2971:
2970:
2967:
2959:
2958:
2953:
2943:
2942:
2938:
2937:
2914:
2913:
2911:
2910:
2897:
2885:
2882:
2881:
2879:
2878:
2877:
2876:
2871:
2861:
2856:
2851:
2846:
2845:
2844:
2839:
2834:
2824:
2823:
2822:
2811:
2809:
2805:
2804:
2801:
2800:
2798:
2797:
2792:
2787:
2785:Mars Institute
2782:
2777:
2770:
2762:
2760:
2756:
2755:
2753:
2752:
2746:
2744:
2738:
2737:
2735:
2734:
2729:
2724:
2719:
2714:
2709:
2704:
2699:
2694:
2688:
2686:
2679:
2673:
2672:
2669:
2668:
2666:
2665:
2659:
2657:
2653:
2652:
2650:
2649:
2643:
2641:
2637:
2636:
2634:
2633:
2632:
2631:
2626:
2621:
2616:
2611:
2606:
2601:
2591:
2590:
2589:
2572:
2566:
2564:
2558:
2557:
2555:
2554:
2553:
2552:
2547:
2539:
2538:
2537:
2532:
2524:
2518:
2516:
2510:
2509:
2507:
2506:
2505:
2504:
2499:
2489:
2488:
2487:
2482:
2471:
2469:
2460:
2454:
2453:
2450:
2449:
2447:
2446:
2441:
2436:
2431:
2426:
2420:
2418:
2412:
2411:
2409:
2408:
2403:
2398:
2393:
2388:
2383:
2378:
2373:
2368:
2363:
2361:Seasonal flows
2358:
2356:Rootless cones
2353:
2348:
2343:
2342:
2341:
2331:
2326:
2321:
2316:
2311:
2310:
2309:
2304:
2294:
2289:
2284:
2279:
2274:
2269:
2264:
2259:
2254:
2249:
2244:
2239:
2234:
2229:
2224:
2219:
2214:
2208:
2206:
2200:
2199:
2197:
2196:
2191:
2186:
2184:Valley network
2181:
2176:
2171:
2169:Observed rocks
2166:
2165:
2164:
2154:
2149:
2144:
2139:
2134:
2129:
2124:
2119:
2114:
2103:
2101:
2093:
2092:
2090:
2089:
2084:
2082:Ultimi Scopuli
2079:
2074:
2069:
2064:
2062:Terra Cimmeria
2059:
2054:
2049:
2044:
2039:
2034:
2029:
2024:
2019:
2014:
2009:
2003:
2001:
1995:
1994:
1992:
1991:
1986:
1981:
1976:
1970:
1968:
1959:
1953:
1952:
1947:
1944:
1943:
1938:
1936:
1935:
1928:
1921:
1913:
1907:
1906:
1900:
1883:
1877:
1862:
1856:
1843:
1837:
1820:
1817:
1815:
1814:
1779:
1770:
1761:
1749:Water on Mars;
1740:
1731:
1718:
1675:
1661:
1648:
1639:
1618:(E9): E09003.
1598:
1591:
1561:
1537:
1510:
1491:(1): 133–161.
1472:
1455:
1442:
1421:
1408:
1391:
1379:
1370:
1353:
1339:
1304:
1266:
1252:
1204:
1166:
1131:
1112:(2): 294–320.
1091:
1043:
995:
951:
941:
939:
936:
914:
911:
899:wrinkle ridges
871:Viking orbiter
863:
860:
817:
812:
777:
773:
740:
737:
704:unconformities
668:
667:
664:
659:
653:
652:
649:
644:
638:
637:
634:
629:
623:
622:
619:
614:
608:
607:
604:
599:
593:
592:
589:
584:
578:
577:
574:
568:
557:
556:
548:
547:
530:
527:
523:geochronologic
416:
413:
406:
398:
378:wrinkle ridges
318:
315:
283:
279:
265:phyllosilicate
256:
248:
245:sulfur dioxide
184:on the planet
168:
167:
162:
158:
157:
152:
148:
147:
142:
138:
137:
133:
132:
129:
125:
124:
119:
118:Celestial body
115:
114:
110:
109:
108:Late Hesperian
106:Early Heperian
104:
100:
99:
95:
94:
76:
68:
67:
60:
55:
50:
45:
44:
36:3700 – 3000
34:
31:
30:
15:
13:
10:
9:
6:
4:
3:
2:
2969:
2968:
2957:
2954:
2952:
2949:
2948:
2946:
2936:
2926:
2922:
2909:
2898:
2896:
2887:
2886:
2883:
2875:
2872:
2870:
2867:
2866:
2865:
2862:
2860:
2857:
2855:
2852:
2850:
2847:
2843:
2840:
2838:
2835:
2833:
2830:
2829:
2828:
2825:
2821:
2818:
2817:
2816:
2813:
2812:
2810:
2806:
2796:
2793:
2791:
2788:
2786:
2783:
2781:
2778:
2776:
2775:
2771:
2769:
2768:
2764:
2763:
2761:
2757:
2751:
2748:
2747:
2745:
2743:
2739:
2733:
2730:
2728:
2725:
2723:
2720:
2718:
2717:Human mission
2715:
2713:
2712:Sample return
2710:
2708:
2705:
2703:
2700:
2698:
2695:
2693:
2690:
2689:
2687:
2683:
2680:
2678:
2674:
2664:
2661:
2660:
2658:
2654:
2648:
2645:
2644:
2642:
2638:
2629:
2622:
2619:
2612:
2609:
2602:
2600:
2597:
2596:
2595:
2592:
2587:
2578:
2577:
2576:
2575:Mars-crossers
2573:
2571:
2568:
2567:
2565:
2563:
2559:
2551:
2548:
2546:
2543:
2542:
2540:
2536:
2533:
2531:
2528:
2527:
2525:
2523:
2520:
2519:
2517:
2515:
2511:
2503:
2500:
2498:
2495:
2494:
2493:
2490:
2486:
2483:
2481:
2478:
2477:
2476:
2473:
2472:
2470:
2468:
2464:
2461:
2459:
2455:
2445:
2442:
2440:
2437:
2435:
2432:
2430:
2427:
2425:
2422:
2421:
2419:
2417:
2413:
2407:
2404:
2402:
2399:
2397:
2394:
2392:
2391:Tharsis bulge
2389:
2387:
2384:
2382:
2379:
2377:
2374:
2372:
2369:
2367:
2364:
2362:
2359:
2357:
2354:
2352:
2349:
2347:
2344:
2340:
2337:
2336:
2335:
2332:
2330:
2329:Ore resources
2327:
2325:
2322:
2320:
2317:
2315:
2312:
2308:
2305:
2303:
2300:
2299:
2298:
2295:
2293:
2290:
2288:
2285:
2283:
2280:
2278:
2275:
2273:
2270:
2268:
2265:
2263:
2260:
2258:
2255:
2253:
2250:
2248:
2245:
2243:
2240:
2238:
2235:
2233:
2230:
2228:
2225:
2223:
2222:Chaos terrain
2220:
2218:
2215:
2213:
2212:Brain terrain
2210:
2209:
2207:
2205:
2201:
2195:
2192:
2190:
2187:
2185:
2182:
2180:
2177:
2175:
2172:
2170:
2167:
2163:
2160:
2159:
2158:
2155:
2153:
2150:
2148:
2145:
2143:
2140:
2138:
2135:
2133:
2130:
2128:
2127:Chaos terrain
2125:
2123:
2120:
2118:
2115:
2112:
2108:
2105:
2104:
2102:
2100:
2094:
2088:
2085:
2083:
2080:
2078:
2075:
2073:
2070:
2068:
2065:
2063:
2060:
2058:
2055:
2053:
2050:
2048:
2045:
2043:
2042:Planum Boreum
2040:
2038:
2035:
2033:
2032:Olympia Undae
2030:
2028:
2025:
2023:
2022:Eridania Lake
2020:
2018:
2015:
2013:
2010:
2008:
2005:
2004:
2002:
2000:
1996:
1990:
1987:
1985:
1982:
1980:
1977:
1975:
1972:
1971:
1969:
1967:
1963:
1960:
1958:
1954:
1950:
1945:
1941:
1934:
1929:
1927:
1922:
1920:
1915:
1914:
1911:
1903:
1901:0-312-42261-X
1897:
1892:
1891:
1884:
1880:
1878:0-7611-2606-6
1874:
1870:
1869:
1863:
1859:
1853:
1849:
1844:
1840:
1834:
1830:
1829:
1823:
1822:
1818:
1810:
1806:
1802:
1798:
1794:
1790:
1783:
1780:
1774:
1771:
1765:
1762:
1758:
1757:0-19-509938-9
1754:
1750:
1744:
1741:
1735:
1732:
1728:
1722:
1719:
1714:
1710:
1706:
1702:
1698:
1694:
1691:(1–2): 9–12.
1690:
1686:
1679:
1676:
1672:
1665:
1662:
1658:
1652:
1649:
1643:
1640:
1634:
1629:
1625:
1621:
1617:
1613:
1609:
1602:
1599:
1594:
1588:
1584:
1580:
1576:
1572:
1565:
1562:
1558:
1557:0-13-390047-9
1554:
1550:
1544:
1542:
1538:
1524:
1520:
1514:
1511:
1506:
1502:
1498:
1494:
1490:
1486:
1479:
1477:
1473:
1469:
1466:H.H. Kieffer
1465:
1459:
1456:
1452:
1446:
1443:
1439:
1435:
1431:
1425:
1422:
1418:
1412:
1409:
1405:
1401:
1398:McCord, T.M.
1395:
1392:
1386:
1384:
1380:
1374:
1371:
1367:
1364:H.H. Kieffer
1363:
1357:
1354:
1348:
1346:
1344:
1340:
1335:
1331:
1327:
1323:
1319:
1315:
1308:
1305:
1300:
1296:
1292:
1288:
1284:
1280:
1273:
1271:
1267:
1263:
1256:
1253:
1248:
1244:
1240:
1236:
1232:
1228:
1224:
1220:
1216:
1208:
1205:
1200:
1196:
1192:
1188:
1184:
1180:
1176:
1175:Werner, S. C.
1170:
1167:
1162:
1158:
1154:
1150:
1146:
1142:
1135:
1132:
1127:
1123:
1119:
1115:
1111:
1107:
1100:
1098:
1096:
1092:
1087:
1083:
1079:
1075:
1071:
1067:
1063:
1059:
1052:
1050:
1048:
1044:
1039:
1035:
1031:
1027:
1023:
1019:
1015:
1008:
1006:
1004:
1002:
1000:
996:
991:
987:
983:
979:
975:
971:
967:
960:
958:
956:
952:
946:
943:
937:
935:
932:
928:
924:
920:
912:
910:
908:
904:
900:
896:
892:
891:Tharsis Bulge
888:
880:
876:
872:
868:
861:
859:
855:
853:
849:
845:
841:
837:
834:
831:in the Upper
830:
826:
811:
809:
804:
800:
795:
792:
783:
771:
766:
759:
755:
751:
745:
738:
736:
734:
730:
729:absolute ages
726:
722:
718:
714:
709:
705:
700:
699:as example.)
698:
694:
693:index fossils
690:
686:
682:
678:
674:
665:
663:
660:
658:
655:
654:
650:
648:
645:
643:
640:
639:
635:
633:
630:
628:
625:
624:
620:
618:
615:
613:
610:
609:
605:
603:
600:
598:
595:
594:
590:
588:
585:
583:
580:
579:
576:Notes (Mars)
575:
573:
572:geochronology
569:
567:
563:
559:
558:
553:
552:
544:
540:
534:
528:
526:
524:
520:
516:
512:
508:
504:
500:
496:
492:
488:
484:
483:geologic unit
481:
477:
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2935:Solar System
2854:Life on Mars
2849:Flag of Mars
2790:Mars Society
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2732:Terraforming
2727:Colonization
2497:Swift crater
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2339:polar wander
2067:Terra Sabaea
2007:Arabia Terra
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210:Late Imbrian
202:absolute age
173:
171:
161:Type section
103:Subdivisions
56:
2677:Exploration
2599:5261 Eureka
2267:Groundwater
2232:Composition
2057:Tempe Terra
2047:Quadrangles
1974:Circulation
1577:: 333–364.
1064:: 165–194.
925:during the
478:. It is an
382:lunar maria
363: /
333:basin. The
307:groundwater
295:groundwater
182:time period
2945:Categories
2334:Polar caps
2314:Mud cracks
2297:Meteorites
2282:Lava tubes
2217:Carbonates
2152:Labyrinthi
2027:Iani Chaos
1966:Atmosphere
1531:2009-09-25
833:Ordovician
725:provenance
708:Cretaceous
657:Chronozone
360:20°S 245°W
303:cryosphere
286:S to form
276:mineralogy
261:weathering
136:Definition
98:Chronology
2859:Sub-Earth
2842:Mythology
2795:Mars race
2562:Asteroids
2458:Astronomy
2429:Hesperian
2424:Amazonian
2396:Volcanism
2371:Spherules
2292:Marsquake
2247:Dichotomy
2162:by height
2157:Mountains
1957:Geography
1713:121719547
844:trilobite
803:referents
770:Alba Mons
685:type area
487:formation
476:landforms
365:-20; -245
335:type area
323:Hesperian
225:volcanism
174:Hesperian
86:type area
29:Hesperian
2895:Category
2759:Advocacy
2742:Missions
2685:Concepts
2514:Transits
2485:Monolith
2434:Noachian
2406:Yardangs
2302:on Earth
2262:Glaciers
2107:"Canals"
2099:features
2097:Physical
1247:16627738
927:Noachian
887:tectonic
879:Noachian
582:Eonothem
519:Noachian
480:inferred
464:spectral
299:regolith
198:Noachian
90:Noachian
21:Hesperia
2827:Fiction
2808:Related
2702:Landing
2697:Orbiter
2656:General
2625:2007 NS
2615:1999 UJ
2605:1998 VF
2594:Trojans
2581:2007 WD
2570:Impacts
2550:Mercury
2416:History
2376:Surface
2307:on Mars
2272:Gullies
2257:Geysers
2204:Geology
2194:Gravity
2189:Valleys
2142:Gullies
2132:Craters
2122:Catenae
2117:Canyons
2072:Tharsis
2017:Cydonia
1999:Regions
1989:Methane
1979:Climate
1797:Bibcode
1693:Bibcode
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1620:Bibcode
1493:Bibcode
1468:et al.,
1366:et al.,
1322:Bibcode
1287:Bibcode
1227:Bibcode
1219:Science
1187:Bibcode
1149:Bibcode
1114:Bibcode
1086:7216371
1066:Bibcode
1026:Bibcode
978:Bibcode
840:System.
829:outcrop
597:Erathem
515:systems
491:stratum
485:(e.g.,
394:Tharsis
273:sulfate
218:Archean
2921:Portal
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2640:Comets
2535:Deimos
2530:Phobos
2492:Deimos
2475:Phobos
2179:Plains
2147:Mensae
2137:Fossae
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1789:Icarus
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852:Period
836:Series
808:Epochs
799:series
758:et al.
754:Viking
750:THEMIS
733:models
723:whose
713:strata
689:strata
681:column
677:period
673:System
627:Series
617:Period
612:System
562:strata
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460:albedo
440:HiRISE
425:strata
331:Hellas
251:) and
155:System
145:Period
84:, the
2707:Rover
2692:Flyby
2663:Orbit
2545:Earth
2467:Moons
2401:Water
2277:Lakes
2227:Color
2077:Undae
1709:S2CID
1526:(PDF)
1464:Mars,
1362:Mars,
1082:S2CID
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662:Chron
642:Stage
632:Epoch
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351:245°W
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220:Eon.
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1553:ISBN
1243:PMID
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269:clay
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180:and
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122:Mars
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