- Email: [email protected]
Planetary Geology Field Symposium, Kitakyushu, Japan, 2011: Planetary geology and terrestrial analogs
Planetary and Space Science 95 (2014) 1–4
Contents lists available at ScienceDirect
Planetary and Space Science journal homepage: www.elsevier.com/locate/pss
Preface
Planetary Geology Field Symposium, Kitakyushu, Japan, 2011: Planetary geology and terrestrial analogs
1. 2011 PERC Planetary Geology Field Symposium and the special issue The 2011 PERC (The Planetary Exploration Research Center of the Chiba Institute of Technology) Planetary Geology Field Symposium (see http://www.perc.it-chiba.ac.jp/meetings/pgfs2011/) was held with the theme “Planetary Geology and Terrestrial Analogs.” The symposium was hosted on 5–6 November 2011 in Kitakyushu City, Kyushu Island, Japan and was followed by a field trip to hot springs and volcanic features in the Beppu-Shimabara Graben. This field symposium was the first of its kind held in Asia (Komatsu and Namiki, 2012). Asia is rich and diverse in geological environments and thus has much to offer in terms of terrestrial analogs for planetary geologic features. Geoscientists versed in relevant features in Asia, and from other regions, have a broader basis for understanding geological processes operating on various planetary bodies. Planetary geology can certainly benefit from the insights and offerings of terrestrial geoscientists familiar with processes and features that may occur in other planetary settings. This special issue gives a taste of what is now being achieved as a result of the expansion in diversity of planetary geology community and terrestrial expertise that is being applied to extraterrestrial geological research. The special issue presented here consists of contributions from Asian and non-Asian scientists who participated in the symposium. The topics of the contributions in the special issue are wide ranging: the methodological concept of planetary geology (Baker, 2014); quantitative analyses based on a new digital global geologic map of Mars (Tanaka et al., 2014); a new hypothesis for the clay mineral formation on Mars (Berger et al., 2014); tsunami wave propagation on an purported ancient ocean on Mars (Iijima et al., 2014); terrestrial analog sites for geological (Komatsu et al., 2014; Essefi et al., 2014) and astrobiological applications (Sugawara et al., 2014; Sakakibara et al., 2014); analysis of boulder distributions on asteroid Itokawa (Miyamoto, 2014); and geological features discovered on Mercury by the MESSENGER spacecraft (Xiao and Komatsu, 2014; published in a previous issue and reprinted in this issue).
2. Candidate terrestrial analog sites in Kyushu, Japan The field trip entitled “Volcanic and geothermal activities along the Beppu-Shimabara Graben as terrestrial analogs for comparative planetary geology” (Komatsu et al., 2011) was held on 7–9 November http://dx.doi.org/10.1016/j.pss.2014.04.002 0032-0633/& 2014 Published by Elsevier Ltd.
Fig. 1. Location map of the field trip entitled “Volcanic and geothermal activities along the Beppu-Shimabara Graben as terrestrial analogs for comparative planetary geology” held on 7–9 November 2011 in central Kyushu Island, Japan.
2011 in central Kyushu Island, Japan after the 2011 PERC Planetary Geology Field Symposium held in Kitakyushu City (Fig. 1). Attendees visited sites along the Beppu-Shimabara Graben trending east–west in the central part of Kyushu. The Beppu-Shimabara Graben is characterized by its associated volcanism, which is expressed in a wide variety of eruptive styles. The most dominant volcanic structure is Aso Volcano (Fig. 1), which is one of the largest caldera structures in the world. The caldera formed primarily 270,000 to 90,000 years ago. Today, only some of its central, interior cones are still active. The Unzen
2
Preface / Planetary and Space Science 95 (2014) 1–4
Volcano (Fig. 1) is located west of Aso, and it is infamous for its pyroclastic flow events—including the one that occurred on 3 June 1991 that killed a number of people including three volcanologists. All the volcanic processes and resulting landforms observable at Aso, Unzen, and Kuju to the east of Aso, provide a diverse set of volcanic analogs for similar features on other terrestrial planets (as well as on the Moon). A remarkable element of the volcanism associated with the Beppu-Shimabara Graben is the fact that its hydrologic interactions are clearly expressed in a variety of forms. Beppu Onsen (Hotspring) (Fig. 1) is well known as a tourist attraction, but it is also scientifically important for the presence of hotspring pools with a range of precipitated minerals. The Aso Volcano is known to have hosted a caldera lake in its past, and it is hypothesized that the lake was catastrophically spilled to the west through a valley. The Mayuyama Volcano, a volcanic edifice near Unzen Volcano, collapsed suddenly into the Ariake Sea on 21 May 1792, thereby producing a gigantic landslide and tsunami that killed more than 15,000 people. Above-mentioned sites along the Beppu-Shimabara Graben can be regarded as terrestrial analog sites for comparative planetary geology. The terrestrial analog aspect of these sites would be useful also in the technological development for planetary exploration. Indeed, rover testing was conducted during and after the symposium at Sunasenrigahama on Aso Volcano. The following subsections describe particularly outstanding examples of the terrestrial analogs. 2.1. Calderas and associated volcanic features in the solar system
implications. The proposed evidence for ancient hydrothermal systems has been linked to the presence of certain landforms such as valley networks, impact craters, and volcanoes where hydrothermal activities were hypothesized to have occurred. An example of the latter is the Dao Vallis outflow channel, which originates from the pervasively dissected Hadriacus Mons volcano have also been speculated to be the sites of hydrothermal activities. The hot springs at Beppu provide an excellent opportunity to observe springs or mud pools where a variety of minerals precipitate (Fig. 2f–h). Silica is particularly relevant to Mars as its discovery in certain locales on the Red Planet has been hypothesized to be linked to the activities of ancient hydrothermal systems. Iron oxides have also been found on Mars, and their deposition is explained by various mechanisms—among them hydrothermal systems. 2.4. Crater lakes and outflow events on Mars The presence of paleo-crater lakes has been hypothesized on Mars for many years. In the case of Mars, the craters hosting the paleo-lakes are most likely of impact origin but there are proposed, ancient volcanic craters that have been dissected by valleys and also may have hosted paleo-lakes. Some such paleocrater lakes may have drained out through spillways breached through the crater rims. The Aso caldera paleo-lake and its proposed catastrophic drainage may be excellent examples for comparing with similarly breached Martian impact and volcanic craters. 2.5. Pyroclastic flows in the solar system
Volcanism occurs on almost all planetary bodies, because it is driven by internal heat loss. Landforms identified as calderas are widely observed, for example, on Mars and the Galilean satellite Io. This fact indicates that effusive and explosive volcanism from shallow magmatic reservoirs operate in the Solar System, and mechanisms for producing conditions sufficient to cause largescale eruption and subsequent collapse exist not only on Earth. Particularly large summit calderas occur on gigantic shield volcanoes on Mars and Venus that were likely formed by non-explosive subsidence due to draining of huge volumes of lava. Scoria (or cinder) cones are relatively small volcanic edifices made of pyroclastic materials, and they seem to occur on planetary surfaces including the ones associated with large shield volcanoes on Mars. The Aso Volcano’s caldera, suite of scoria cones and other associated volcanic landforms are excellent terrestrial analogs for planetary volcanism due to their pristine preservation states and easy access (Fig. 2a, b, and d).
Pyroclastic flows (or ash falls) may be common on planetary bodies. For example, some localized geological observations indicating ancient pyroclastic flow events have been reported on Mars. Mars is known for its ubiquitous occurrence of layered materials identified on its surface from orbit, and a possibility exists that some of them resulted from pyroclastic activities. Recognition of pyroclastic deposits on planetary surfaces is not an easy task. Without outcrop examinations, layered deposits resulted from pyroclastic activities could be indistinguishable from stratifications produced by deposition of non-volcanic materials such as eolian and authigenic sediments. The widespread pyroclastic deposits in central Kyushu (e.g., Fig. 2c) provide insightful examples useful for learning what to look for in the identification of pyroclastic deposits on planetary surfaces.
2.2. Extensional faulting and volcanism in the solar system
2.6. Failures of volcanic edifices on planetary surfaces
The east–west trending Beppu-Shimabara Graben in central Kyushu (Figs. 1 and 2e) provides an example in which extensional faulting controls the location of associated volcanism. The east– west aligning Kuju, Aso and Unzen Volcanoes occur along grabenbounding normal faults. Normal faulting represents the brittle failure of crustal materials in response to extensional stress fields, and it appears to be very common on planetary surfaces. Such faults are often accompanied by volcanism. For example, large volcanic features are found to straddle over rift systems on Venus. On Mars, lava flows emanating from grabens are observed.
Evidence for volcanic edifice failures has been noted on planetary surfaces such as on Venus and Mars. Such failures indicate that volcanic edifices are inherently unstable, and they could collapse by a variety of triggering mechanisms. They are an effective way to contribute to the degradation of volcanic edifices. The failure of the Mayuyama Volcano occurred relatively recently (21 May 1792), and the landforms resulting from the failure event are well preserved in both the volcano edifice and on the sea floor in front of the edifice.
2.3. Geothermal processes and astrobiology
Powerful tsunami waves such as the ones caused by the Mayuyama Volcano failures or by other mechanisms are the subject of interest for planets or satellites with bodies of water (or other liquids) today or in the past. In the present-day, the
Geothermal processes involving water have been debated extensively for their possible roles on Mars, which include astrobiological
2.7. Tsunami occurrences in the solar system?
Preface / Planetary and Space Science 95 (2014) 1–4
3
Fig. 2. Representative geological sites visited during the field trip. These sites were chosen for visits because of their significance for planetary geology: (a) view of the Aso caldera and post-caldera central cones; (b) Sunasenrigahama on Aso Volcano, where rover testing was conducted during and after the symposium; (c) pyroclastic flow deposit emanating from Unzen Volcano; (d) the Kamikomezuka scoria cone (cross section) in the Aso caldera; (e) normal fault (on the left) of the Beppu-Shimabara Graben; and (f–h) Beppu hotspring pools of various chemical and mineralogical compositions, resulting in color variations.
only Solar System body with a certain presence of liquid bodies on the surface besides Earth is Titan, an icy satellite of Saturn. And tsunami may have occurred in lakes (or seas) of the satellite. Many observations are pointing to the past existence of bodies of water up to the size of large lakes and even oceans on Mars. Therefore, the prospect of tsunami occurrence on ancient Mars should not be neglected. Possible modes of tsunami wave generation could be diverse ranging from Mars quakes, landslides to impact cratering, and their morphological and sedimentological influences on shoreline zones could have been significant.
References Baker, V.R., 2014. Terrestrial analogs, planetary geology, and the nature of geological reasoning. Planet. Space Sci. 95, 5–10, http://dx.doi.org/10.1016/j.pss. 2012.10.008. Berger, G., Meunier, A., Beaufort, D., 2014. Clay mineral formation on Mars: Chemical constraints and possible contribution of basalt out-gassing. Planet. Space Sci. 95, 25–32, http://dx.doi.org/10.1016/j.pss.2013.05.024. Essefi, E., Komatsu, G., Fairén, A.G., Chan, M.A., Yaich, C., 2014. Groundwater influence on the aeolian sequence stratigraphy of the Mechertate-Chrita-Sidi El Hani system, Tunisian Sahel: Analogies to the wet-dry aeolian sequence stratigraphy at Meridiani Planum, Terby crater, and Gale crater, Mars. Planet. Space Sci. 95, 56–78, http://dx.doi.org/10.1016/j.pss.2013.05.010.
4
Preface / Planetary and Space Science 95 (2014) 1–4
Iijima, Y., Goto, K., Minoura, K., Komatsu, G., Imamura, F., 2014. Hydrodynamics of impact-induced tsunami over the Martian ocean. Planet. Space Sci. 95, 33–44, http://dx.doi.org/10.1016/j.pss.2013.09.014. Komatsu, G., Namiki, N., 2012. Planetary geology and terrestrial analogs in Asia. EOS 93 (16), 164, http://dx.doi.org/10.1029/2012EO160004. Komatsu, G., Goto, K., Shibuya, H. (eds), 2011. Volcanic and Geothermal Activities Along the Beppu-Shimabara Graben as Terrestrial Analogs for Comparative Planetary Geology. Guidebook for Field Trip. 2011 PERC Planetary Geology Field Symposium, Kitakyushu, 62 pp. Komatsu, G., Senthil Kumar, P., Goto, K., Sekine, Y., Giri, C., Matsui, T., 2014. Drainage systems of Lonar Crater, India: Contributions to Lonar Lake hydrology and crater degradation. Planet. Space Sci. 95, 45–55, http://dx.doi.org/10.1016/j.pss. 2013.05.011. Miyamoto, H., 2014. Unconsolidated boulders on the surface of Itokawa. Planet. Space Sci. 95, 94–102, http://dx.doi.org/10.1016/j.pss.2013.06.016. Sakakibara, M., Sugawara, H., Tsuji, T., Ikehara, M., 2014. Filamentous microbial fossil from low-grade metamorphosed basalt in northern Chichibu belt, central Shikoku, Japan. Planet. Space Sci. 95, 84–93, http://dx.doi.org/10.1016/j.pss. 2013.05.008. Sugawara, H., Sakakibara, M., Ikehara, M., 2014. Recrystallized microbial trace fossils from metamorphosed Permian basalt, southwestern Japan. Planet. Space Sci. 95, 79–83, http://dx.doi.org/10.1016/j.pss.2013.09.018. Tanaka, K.L., Robbins, S.J., Fortezzo, C.M., Skinner Jr, J.A., Hare, T.M., 2014. The digital global geologic map of Mars: Chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history. Planet. Space Sci. 95, 11–24, http://dx.doi.org/10.1016/j.pss.2013.03.006.
Xiao, Z., Komatsu, G., 2014. Reprint of: Impact craters with ejecta flows and central pits on Mercury. Planet. Space Sci. 95, 103–119, http://dx.doi.org/10.1016/j.pss. 2013.07.001.
Goro Komatsu n International Research School of Planetary Sciences, Università d’Annunzio, Viale Pindaro 42, 65127 Pescara, Italy E-mail address: [email protected]
Kazuhisa Goto International Research Institute of Disaster Science, Tohoku University, Aoba 6-6-11-1106, Aramaki, Aoba-ku, Sendai 980-8579, Japan Planetary Exploration Research Center, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino-shi, Chiba 275-0016, Japan
Kenneth L. Tanaka Astrogeology Science Center, U.S. Geological Survey, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA
n
Corresponding author. Tel.: þ 39 085 453 7884; fax: þ39 085 453 7545.
Contents lists available at ScienceDirect
Planetary and Space Science journal homepage: www.elsevier.com/locate/pss
Preface
Planetary Geology Field Symposium, Kitakyushu, Japan, 2011: Planetary geology and terrestrial analogs
1. 2011 PERC Planetary Geology Field Symposium and the special issue The 2011 PERC (The Planetary Exploration Research Center of the Chiba Institute of Technology) Planetary Geology Field Symposium (see http://www.perc.it-chiba.ac.jp/meetings/pgfs2011/) was held with the theme “Planetary Geology and Terrestrial Analogs.” The symposium was hosted on 5–6 November 2011 in Kitakyushu City, Kyushu Island, Japan and was followed by a field trip to hot springs and volcanic features in the Beppu-Shimabara Graben. This field symposium was the first of its kind held in Asia (Komatsu and Namiki, 2012). Asia is rich and diverse in geological environments and thus has much to offer in terms of terrestrial analogs for planetary geologic features. Geoscientists versed in relevant features in Asia, and from other regions, have a broader basis for understanding geological processes operating on various planetary bodies. Planetary geology can certainly benefit from the insights and offerings of terrestrial geoscientists familiar with processes and features that may occur in other planetary settings. This special issue gives a taste of what is now being achieved as a result of the expansion in diversity of planetary geology community and terrestrial expertise that is being applied to extraterrestrial geological research. The special issue presented here consists of contributions from Asian and non-Asian scientists who participated in the symposium. The topics of the contributions in the special issue are wide ranging: the methodological concept of planetary geology (Baker, 2014); quantitative analyses based on a new digital global geologic map of Mars (Tanaka et al., 2014); a new hypothesis for the clay mineral formation on Mars (Berger et al., 2014); tsunami wave propagation on an purported ancient ocean on Mars (Iijima et al., 2014); terrestrial analog sites for geological (Komatsu et al., 2014; Essefi et al., 2014) and astrobiological applications (Sugawara et al., 2014; Sakakibara et al., 2014); analysis of boulder distributions on asteroid Itokawa (Miyamoto, 2014); and geological features discovered on Mercury by the MESSENGER spacecraft (Xiao and Komatsu, 2014; published in a previous issue and reprinted in this issue).
2. Candidate terrestrial analog sites in Kyushu, Japan The field trip entitled “Volcanic and geothermal activities along the Beppu-Shimabara Graben as terrestrial analogs for comparative planetary geology” (Komatsu et al., 2011) was held on 7–9 November http://dx.doi.org/10.1016/j.pss.2014.04.002 0032-0633/& 2014 Published by Elsevier Ltd.
Fig. 1. Location map of the field trip entitled “Volcanic and geothermal activities along the Beppu-Shimabara Graben as terrestrial analogs for comparative planetary geology” held on 7–9 November 2011 in central Kyushu Island, Japan.
2011 in central Kyushu Island, Japan after the 2011 PERC Planetary Geology Field Symposium held in Kitakyushu City (Fig. 1). Attendees visited sites along the Beppu-Shimabara Graben trending east–west in the central part of Kyushu. The Beppu-Shimabara Graben is characterized by its associated volcanism, which is expressed in a wide variety of eruptive styles. The most dominant volcanic structure is Aso Volcano (Fig. 1), which is one of the largest caldera structures in the world. The caldera formed primarily 270,000 to 90,000 years ago. Today, only some of its central, interior cones are still active. The Unzen
2
Preface / Planetary and Space Science 95 (2014) 1–4
Volcano (Fig. 1) is located west of Aso, and it is infamous for its pyroclastic flow events—including the one that occurred on 3 June 1991 that killed a number of people including three volcanologists. All the volcanic processes and resulting landforms observable at Aso, Unzen, and Kuju to the east of Aso, provide a diverse set of volcanic analogs for similar features on other terrestrial planets (as well as on the Moon). A remarkable element of the volcanism associated with the Beppu-Shimabara Graben is the fact that its hydrologic interactions are clearly expressed in a variety of forms. Beppu Onsen (Hotspring) (Fig. 1) is well known as a tourist attraction, but it is also scientifically important for the presence of hotspring pools with a range of precipitated minerals. The Aso Volcano is known to have hosted a caldera lake in its past, and it is hypothesized that the lake was catastrophically spilled to the west through a valley. The Mayuyama Volcano, a volcanic edifice near Unzen Volcano, collapsed suddenly into the Ariake Sea on 21 May 1792, thereby producing a gigantic landslide and tsunami that killed more than 15,000 people. Above-mentioned sites along the Beppu-Shimabara Graben can be regarded as terrestrial analog sites for comparative planetary geology. The terrestrial analog aspect of these sites would be useful also in the technological development for planetary exploration. Indeed, rover testing was conducted during and after the symposium at Sunasenrigahama on Aso Volcano. The following subsections describe particularly outstanding examples of the terrestrial analogs. 2.1. Calderas and associated volcanic features in the solar system
implications. The proposed evidence for ancient hydrothermal systems has been linked to the presence of certain landforms such as valley networks, impact craters, and volcanoes where hydrothermal activities were hypothesized to have occurred. An example of the latter is the Dao Vallis outflow channel, which originates from the pervasively dissected Hadriacus Mons volcano have also been speculated to be the sites of hydrothermal activities. The hot springs at Beppu provide an excellent opportunity to observe springs or mud pools where a variety of minerals precipitate (Fig. 2f–h). Silica is particularly relevant to Mars as its discovery in certain locales on the Red Planet has been hypothesized to be linked to the activities of ancient hydrothermal systems. Iron oxides have also been found on Mars, and their deposition is explained by various mechanisms—among them hydrothermal systems. 2.4. Crater lakes and outflow events on Mars The presence of paleo-crater lakes has been hypothesized on Mars for many years. In the case of Mars, the craters hosting the paleo-lakes are most likely of impact origin but there are proposed, ancient volcanic craters that have been dissected by valleys and also may have hosted paleo-lakes. Some such paleocrater lakes may have drained out through spillways breached through the crater rims. The Aso caldera paleo-lake and its proposed catastrophic drainage may be excellent examples for comparing with similarly breached Martian impact and volcanic craters. 2.5. Pyroclastic flows in the solar system
Volcanism occurs on almost all planetary bodies, because it is driven by internal heat loss. Landforms identified as calderas are widely observed, for example, on Mars and the Galilean satellite Io. This fact indicates that effusive and explosive volcanism from shallow magmatic reservoirs operate in the Solar System, and mechanisms for producing conditions sufficient to cause largescale eruption and subsequent collapse exist not only on Earth. Particularly large summit calderas occur on gigantic shield volcanoes on Mars and Venus that were likely formed by non-explosive subsidence due to draining of huge volumes of lava. Scoria (or cinder) cones are relatively small volcanic edifices made of pyroclastic materials, and they seem to occur on planetary surfaces including the ones associated with large shield volcanoes on Mars. The Aso Volcano’s caldera, suite of scoria cones and other associated volcanic landforms are excellent terrestrial analogs for planetary volcanism due to their pristine preservation states and easy access (Fig. 2a, b, and d).
Pyroclastic flows (or ash falls) may be common on planetary bodies. For example, some localized geological observations indicating ancient pyroclastic flow events have been reported on Mars. Mars is known for its ubiquitous occurrence of layered materials identified on its surface from orbit, and a possibility exists that some of them resulted from pyroclastic activities. Recognition of pyroclastic deposits on planetary surfaces is not an easy task. Without outcrop examinations, layered deposits resulted from pyroclastic activities could be indistinguishable from stratifications produced by deposition of non-volcanic materials such as eolian and authigenic sediments. The widespread pyroclastic deposits in central Kyushu (e.g., Fig. 2c) provide insightful examples useful for learning what to look for in the identification of pyroclastic deposits on planetary surfaces.
2.2. Extensional faulting and volcanism in the solar system
2.6. Failures of volcanic edifices on planetary surfaces
The east–west trending Beppu-Shimabara Graben in central Kyushu (Figs. 1 and 2e) provides an example in which extensional faulting controls the location of associated volcanism. The east– west aligning Kuju, Aso and Unzen Volcanoes occur along grabenbounding normal faults. Normal faulting represents the brittle failure of crustal materials in response to extensional stress fields, and it appears to be very common on planetary surfaces. Such faults are often accompanied by volcanism. For example, large volcanic features are found to straddle over rift systems on Venus. On Mars, lava flows emanating from grabens are observed.
Evidence for volcanic edifice failures has been noted on planetary surfaces such as on Venus and Mars. Such failures indicate that volcanic edifices are inherently unstable, and they could collapse by a variety of triggering mechanisms. They are an effective way to contribute to the degradation of volcanic edifices. The failure of the Mayuyama Volcano occurred relatively recently (21 May 1792), and the landforms resulting from the failure event are well preserved in both the volcano edifice and on the sea floor in front of the edifice.
2.3. Geothermal processes and astrobiology
Powerful tsunami waves such as the ones caused by the Mayuyama Volcano failures or by other mechanisms are the subject of interest for planets or satellites with bodies of water (or other liquids) today or in the past. In the present-day, the
Geothermal processes involving water have been debated extensively for their possible roles on Mars, which include astrobiological
2.7. Tsunami occurrences in the solar system?
Preface / Planetary and Space Science 95 (2014) 1–4
3
Fig. 2. Representative geological sites visited during the field trip. These sites were chosen for visits because of their significance for planetary geology: (a) view of the Aso caldera and post-caldera central cones; (b) Sunasenrigahama on Aso Volcano, where rover testing was conducted during and after the symposium; (c) pyroclastic flow deposit emanating from Unzen Volcano; (d) the Kamikomezuka scoria cone (cross section) in the Aso caldera; (e) normal fault (on the left) of the Beppu-Shimabara Graben; and (f–h) Beppu hotspring pools of various chemical and mineralogical compositions, resulting in color variations.
only Solar System body with a certain presence of liquid bodies on the surface besides Earth is Titan, an icy satellite of Saturn. And tsunami may have occurred in lakes (or seas) of the satellite. Many observations are pointing to the past existence of bodies of water up to the size of large lakes and even oceans on Mars. Therefore, the prospect of tsunami occurrence on ancient Mars should not be neglected. Possible modes of tsunami wave generation could be diverse ranging from Mars quakes, landslides to impact cratering, and their morphological and sedimentological influences on shoreline zones could have been significant.
References Baker, V.R., 2014. Terrestrial analogs, planetary geology, and the nature of geological reasoning. Planet. Space Sci. 95, 5–10, http://dx.doi.org/10.1016/j.pss. 2012.10.008. Berger, G., Meunier, A., Beaufort, D., 2014. Clay mineral formation on Mars: Chemical constraints and possible contribution of basalt out-gassing. Planet. Space Sci. 95, 25–32, http://dx.doi.org/10.1016/j.pss.2013.05.024. Essefi, E., Komatsu, G., Fairén, A.G., Chan, M.A., Yaich, C., 2014. Groundwater influence on the aeolian sequence stratigraphy of the Mechertate-Chrita-Sidi El Hani system, Tunisian Sahel: Analogies to the wet-dry aeolian sequence stratigraphy at Meridiani Planum, Terby crater, and Gale crater, Mars. Planet. Space Sci. 95, 56–78, http://dx.doi.org/10.1016/j.pss.2013.05.010.
4
Preface / Planetary and Space Science 95 (2014) 1–4
Iijima, Y., Goto, K., Minoura, K., Komatsu, G., Imamura, F., 2014. Hydrodynamics of impact-induced tsunami over the Martian ocean. Planet. Space Sci. 95, 33–44, http://dx.doi.org/10.1016/j.pss.2013.09.014. Komatsu, G., Namiki, N., 2012. Planetary geology and terrestrial analogs in Asia. EOS 93 (16), 164, http://dx.doi.org/10.1029/2012EO160004. Komatsu, G., Goto, K., Shibuya, H. (eds), 2011. Volcanic and Geothermal Activities Along the Beppu-Shimabara Graben as Terrestrial Analogs for Comparative Planetary Geology. Guidebook for Field Trip. 2011 PERC Planetary Geology Field Symposium, Kitakyushu, 62 pp. Komatsu, G., Senthil Kumar, P., Goto, K., Sekine, Y., Giri, C., Matsui, T., 2014. Drainage systems of Lonar Crater, India: Contributions to Lonar Lake hydrology and crater degradation. Planet. Space Sci. 95, 45–55, http://dx.doi.org/10.1016/j.pss. 2013.05.011. Miyamoto, H., 2014. Unconsolidated boulders on the surface of Itokawa. Planet. Space Sci. 95, 94–102, http://dx.doi.org/10.1016/j.pss.2013.06.016. Sakakibara, M., Sugawara, H., Tsuji, T., Ikehara, M., 2014. Filamentous microbial fossil from low-grade metamorphosed basalt in northern Chichibu belt, central Shikoku, Japan. Planet. Space Sci. 95, 84–93, http://dx.doi.org/10.1016/j.pss. 2013.05.008. Sugawara, H., Sakakibara, M., Ikehara, M., 2014. Recrystallized microbial trace fossils from metamorphosed Permian basalt, southwestern Japan. Planet. Space Sci. 95, 79–83, http://dx.doi.org/10.1016/j.pss.2013.09.018. Tanaka, K.L., Robbins, S.J., Fortezzo, C.M., Skinner Jr, J.A., Hare, T.M., 2014. The digital global geologic map of Mars: Chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history. Planet. Space Sci. 95, 11–24, http://dx.doi.org/10.1016/j.pss.2013.03.006.
Xiao, Z., Komatsu, G., 2014. Reprint of: Impact craters with ejecta flows and central pits on Mercury. Planet. Space Sci. 95, 103–119, http://dx.doi.org/10.1016/j.pss. 2013.07.001.
Goro Komatsu n International Research School of Planetary Sciences, Università d’Annunzio, Viale Pindaro 42, 65127 Pescara, Italy E-mail address: [email protected]
Kazuhisa Goto International Research Institute of Disaster Science, Tohoku University, Aoba 6-6-11-1106, Aramaki, Aoba-ku, Sendai 980-8579, Japan Planetary Exploration Research Center, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino-shi, Chiba 275-0016, Japan
Kenneth L. Tanaka Astrogeology Science Center, U.S. Geological Survey, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA
n
Corresponding author. Tel.: þ 39 085 453 7884; fax: þ39 085 453 7545.