Journal articles: 'Planet geology'

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Klimczak, Christian, Paul K. Byrne, A. M. Celâl Şengör, and Sean C. Solomon. "Principles of structural geology on rocky planets." Canadian Journal of Earth Sciences 56, no. 12 (December 2019): 1437–57. http://dx.doi.org/10.1139/cjes-2019-0065.

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Although Earth is the only known planet on which plate tectonics operates, many small- and large-scale tectonic landforms indicate that deformational processes also occur on the other rocky planets. Although the mechanisms of deformation differ on Mercury, Venus, and Mars, the surface manifestations of their tectonics are frequently very similar to those found on Earth. Furthermore, tectonic processes invoked to explain deformation on Earth before the recognition of horizontal mobility of tectonic plates remain relevant for the other rocky planets. These connections highlight the importance of drawing analogies between the rocky planets for characterizing deformation of their lithospheres and for describing, applying appropriate nomenclature, and understanding the formation of their resulting tectonic structures. Here we characterize and compare the lithospheres of the rocky planets, describe structures of interest and where we study them, provide examples of how historic views on geology are applicable to planetary tectonics, and then apply these concepts to Mercury, Venus, and Mars.

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Searle, R. C. "Marine geology — A planet earth perspective." Marine and Petroleum Geology 5, no. 3 (August 1988): 300. http://dx.doi.org/10.1016/0264-8172(88)90011-6.

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Yusoff, Kathryn. "Geosocial Strata." Theory, Culture & Society 34, no. 2-3 (January 18, 2017): 105–27. http://dx.doi.org/10.1177/0263276416688543.

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The Anthropocene marks a moment of wild destratification of the planet that requires analysis of the relations between geologic forces and social practices. Deleuze and Guattari’s concept of strata is examined in order to develop a geophilosophy for the Anthropocene. Establishing a model of strata that conjoins earth and social flows together into planes of interrelated production highlights how the fossil substratum subtends contemporary forms of social relations. Stratifications, it is argued, are planes of social reproduction that both constrain and are expressive of possible modes of expression (and thus political freedom). If power, according to Foucault, is a relation between forces, geosocial strata conceptualizes how stratifications organize and capture forces into political geology. Concentrating on diagramming moments of crossing strata, it is suggested that Anthropocene geopolitics needs to be located at the intersection of geosocial formations and processes of fossilization, rather than through a new assemblage of planetary scale.

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Goldblatt, C., K. J. Zahnle, N. H. Sleep, and E. G. Nisbet. "The Eons of Chaos and Hades." Solid Earth 1, no. 1 (February 2, 2010): 1–3. http://dx.doi.org/10.5194/se-1-1-2010.

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Abstract. We propose the Chaotian Eon to demarcate geologic time from the origin of the Solar System to the Moon-forming impact on Earth. This separates the solar system wide processes of planet formation from the subsequent divergent evolution of the inner planets. We further propose the division of the Hadean Eon into eras and periods and naming the proto-Earth Tellus.

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Sanloup, Chrystele. "High-pressure experimental geosciences: state of the art and prospects." Bulletin de la Société Géologique de France 183, no. 3 (May 1, 2012): 175–87. http://dx.doi.org/10.2113/gssgfbull.183.3.175.

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Abstract This paper aims at reviewing the current advancements of high pressure experimental geosciences. The angle chosen is that of in situ measurements at the high pressure (P) and high temperature (T) conditions relevant of the deep Earth and planets, measurements that are often carried out at large facilities (X-ray synchrotrons and neutron sources). Rather than giving an exhaustive catalogue, four main active areas of research are chosen: the latest advancements on deep Earth mineralogy, how to probe the properties of melts, how to probe Earth dynamics, and chemical reactivity induced by increased P-T conditions. For each area, techniques are briefly presented and selected examples illustrate their potentials, and what that tell us about the structure and dynamics of the planet.

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SUWA, K. "The Planet Earth Viewed from Africa." Gondwana Research 6, no. 4 (October 2003): 961. http://dx.doi.org/10.1016/s1342-937x(05)71050-9.

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Bridges, N. T., M. C. Bourke, P. E. Geissler, M. E. Banks, C. Colon, S. Diniega, M. P. Golombek, et al. "Planet-wide sand motion on Mars." Geology 40, no. 1 (November 14, 2011): 31–34. http://dx.doi.org/10.1130/g32373.1.

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Mangel, Adam, and Steve Sloan. "Introduction to this special section: Near-surface geophysics." Leading Edge 38, no. 6 (June 2019): 434. http://dx.doi.org/10.1190/tle38060434.1.

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The near surface of the earth, a.k.a. the critical zone (National Research Council, 2001), is defined as the outer 50–100 m of the planet, which contains biota, bedrock, soil, water, and gasses. As humans, we rely on this layer for many functions including storage of water resources, housing of our infrastructure, storage of our wastes, and cultivation of our food sources. Several natural ecosystems are also dependent on this layer of our planet, which in turn provide us with ecosystem services. The historic and lasting importance of this layer to our environment emphasizes the value in understanding major environmental fluxes, impact of human activities, and the interface between the natural world and our infrastructure. Application of geophysical methods in this field has increased steadily over the past 15 years and continues to grow, especially as the human impact on the globe continues to increase.

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Kwok, Sun, Edwin Bergin, and Pascale Ehrenfreund. "Search for water and life's building blocks in the Universe." Proceedings of the International Astronomical Union 11, A29B (August 2015): 375. http://dx.doi.org/10.1017/s1743921316005573.

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Water is the common ground between astronomy and planetary science as the presence of water on a planet is universally accepted as essential for its potential habitability. Water assists many biological chemical reactions leading to complexity by acting as an effective solvent. It shapes the geology and climate on rocky planets, and is a major or primary constituent of the solid bodies of the outer solar system. Water ice seems universal in space and is by far the most abundant condensed-phase species in our universe. Water-rich icy layers cover dust particles within the cold regions of the interstellar medium and molecular ices are widespread in the solar system. The poles of terrestrial planets (e.g. Earth, Mars) and most of the outer-solar-system satellites are covered with ice. Smaller solar system bodies, such as comets and Kuiper Belt Objects (KBOs), contain a significant fraction of water ice and trace amounts of organics. Beneath the ice crust of several moons of Jupiter and Saturn liquid water oceans probably exist.

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10

Paschoale, Conrado, and Silvia de Mendonca Figueiroa. "Geologic Time: A Semiotic Probing." Earth Sciences History 8, no. 2 (January 1, 1989): 116–22. http://dx.doi.org/10.17704/eshi.8.2.9w10334423243554.

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Time is a continuum and is real, according to Peircean theory. It is also the constitutive category of geology that is equivalent to the Peircean category of Thirdness. As a continuum, time was created and evolved. Although the conceptions of a linear and a cyclic time played a role in the development of geological science, they were not deduced from geological observations; they were a priori assumptions. Hence, time is a methodological device. Continuity, for Peirce, exists on evolutionary terms. Chance or Firstness is always present in every phenomenon. So, time is continual rather then continuous, a continuum where new possibilities of development can be added, by the action of Chance or Firstness. The notion of cycle in geologic time should be reviewed. For Peirce real time is multiply- or n-tracked. Real time is open to firstness. According to this, geologic time is the vestige, a great vestige, of the fixed and definite track which, within the n-possibilities of development, the planet evolved, incorporating changes produced by chance.

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11

Billups, K. "Microfossils Reveal the Workings of a Water Planet." Geology 38, no. 9 (August 19, 2010): 863–64. http://dx.doi.org/10.1130/focus092010.1.

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Itaya, T., K. Sajeev, C. Clark, and M. A. Kusiak. "Micro-chronology and evolution of the planet Earth." Gondwana Research 14, no. 4 (December 2008): 567–68. http://dx.doi.org/10.1016/j.gr.2008.03.002.

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13

Muir Wood, D. "Quaternary engineering geology: a summary." Geological Society, London, Engineering Geology Special Publications 7, no. 1 (1991): 713–15. http://dx.doi.org/10.1144/gsl.eng.1991.007.01.73.

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IntroductionThe position of the summer-up is perhaps the least to be envied of all those invited to speak at this Conference: others can say their piece and then relax, or even depart (Fig 1); he has to attend every session and to hear all that is said knowing that his own remarks are likely to be made to an ever-dwindling audience. It would be nice to be able to feel that the importance of the various elements of the conference was inversely proportional to their duration (Fig 2) - just as this conference has thrown the spotlight uniquely on the Quaternary, which occupies but the smallest fraction of the geological history of our planet. We are told that the Quaternary represents the last 4 hours of the earth’s history compressed to 1 year : the summing up represents the last few minutes of the four days of the conference.As a period of geological history, the Quaternary encompasses a whole spectrum of climatic variations. Though there has been concentration in this conference on processes more or less loosely associated with glaciation, other processes have continued also. It is only by understanding the processess by which the surface of the earth has been shaped that we can hope to form a coherent picture of the distribution of soils and rocks and their properties.Our concentration in civil engineering tends to be on structures with a lifetime of, say, 50 to 100 years.

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Milsom, John. "Extreme gravity: Geologic effects." Leading Edge 39, no. 6 (June 2020): 430–33. http://dx.doi.org/10.1190/tle39060430.1.

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The maximum positive combined effect on the earth's gravity field of all geologic sources present in a given area, including any isostatic compensation, is limited by the ability of the lithosphere to support load. Bouguer gravity is one possible proxy for this effect. Bouguer maxima close to +350 mGal have been measured on Chichijima Island and Penrhyn Atoll in the Pacific Ocean. These may be the highest values anywhere on the planet. Suggestions of even higher values in the northernmost segment of the Colombian Andes rely on extrapolation of trends established in areas surrounding the Santa Marta Massif and must be treated with caution.

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15

Bell, Michael A. "Planet Earth: Cosmology, Geology, and the Evolution of Life and Environment.Cesare Emiliani." Quarterly Review of Biology 69, no. 1 (March 1994): 136. http://dx.doi.org/10.1086/418528.

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ŞENGÖR, A. M. C. "SOME NOTES TOWARDS A HISTORY OF IDEAS ON RIFTS AND EXTENSIONAL TECTONICS IN GENERAL." Earth Sciences History 37, no. 1 (January 1, 2018): 144–56. http://dx.doi.org/10.17704/1944-6178-37.1.144.

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ABSTRACT The history of ideas on extensional tectonics is somewhat neglected in the general historiography of geology. This is because the occurrence of widespread extension on our planet was recognised late, although normal dip-slip faults are by far the most common of fault types and this had been noticed since the early days of mining. A review of the geological literature shows, however, that many geologists and miners did think of widespread extension on earth very early on. Their ideas did not have the same impact as ideas on shortening structures, because the latter are visually so much more spectacular in Europe, where the science of geology was born. Observations thus do govern the spread of ideas in the sciences, contrary to what many in the social disciplines claim.

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Hoffman, Nick. "White Mars: The story of the Red Planet, without water." Leading Edge 22, no. 8 (August 2003): 772–74. http://dx.doi.org/10.1190/1.1605079.

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Grubic, Aleksandar. "Original meaning of the notion and term “formation” in geology." Annales g?ologiques de la Peninsule balkanique, no. 75 (2014): 33–42. http://dx.doi.org/10.2298/gabp1475033g.

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The notion of (geological) formation has gradually developed through mostly German terms: from ein Gebirge, which was used by Saxon miners for several centuries (AGRICOLA), then Schichten, Bergart (LEHMANN) and serie montana (FUCHSEL) to Gebirgsart (WERNER). The term ?formation? was introduced by WERNER in 1791 and its meaning was clearly defined around 1800. He included the notion of ?formation? into his system of ?geognostic structures?: mineral; rock (layer); formation; Earth?s crust. Therefore, it was an equivocal term from the start. It implied a geological body of certain composition, genesis and superposition (i.e. time of origination). After Werner, the term ?formation? was used in different ways, mostly as a synonym for a ?system?, until 1881 when such use was forbidden. The original Wernerian sense of the term ?formation? (as a unit in geological levels of organisation: mineral-rock-formation-geosphere-planet) with an intentionally equivocal meaning was not restored until the second half of the twentieth century.

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Wrona, Thilo, Indranil Pan, Rebecca E. Bell, Robert L. Gawthorpe, Haakon Fossen, and Sascha Brune. "3D seismic interpretation with deep learning: A brief introduction." Leading Edge 40, no. 7 (July 2021): 524–32. http://dx.doi.org/10.1190/tle40070524.1.

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Understanding the internal structure of our planet is a fundamental goal of the earth sciences. As direct observations are restricted to surface outcrops and borehole cores, we rely on geophysical data to study the earth's interior. In particular, seismic reflection data showing acoustic images of the subsurface provide us with critical insights into sedimentary, tectonic, and magmatic systems. However, interpretations of these large 2D grids or 3D seismic volumes are time-consuming, even for a well-trained person or team. Here, we demonstrate how to automate and accelerate the analysis of these increasingly large seismic data sets with machine learning. We are able to perform typical seismic interpretation tasks such as mapping tectonic faults, salt bodies, and sedimentary horizons at high accuracy using deep convolutional neural networks. We share our workflows and scripts, encouraging users to apply our methods to similar problems. Our methodology is generic and flexible, allowing an easy adaptation without major changes. Once trained, these models can analyze large volumes of data within seconds, opening a new pathway to study the processes shaping the internal structure of our planet.

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Yesipovich, S. M. "STAGES OF DEVELOPMENT OF THE PLANET EARTH IN THE FRAMEWORK OF ANALYTICAL GEOLOGY." Tectonics and Stratigraphy, no. 44 (December 28, 2017): 5–29. http://dx.doi.org/10.30836/igs.0375-7773.2017.147549.

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21

Thangjam, G., A. Nathues, T. Platz, M. Hoffmann, E. A. Cloutis, K. Mengel, M. R. M. Izawa, and D. M. Applin. "Spectral properties and geology of bright and dark material on dwarf planet Ceres." Meteoritics & Planetary Science 53, no. 9 (January 22, 2018): 1961–82. http://dx.doi.org/10.1111/maps.13044.

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22

Derickson, Kate Driscoll. "Urban geography III." Progress in Human Geography 42, no. 3 (January 5, 2017): 425–35. http://dx.doi.org/10.1177/0309132516686012.

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Geologists are considering in earnest whether to mark the emergence of a new geological epoch – characterized by human impacts on the geology of the planet – as the dawn of the Anthropocene. In this third of three urban geography progress reports, I identify interrelated elements of what I call ‘Anthropocene thinking’ – non-linearity, reworked temporalities, and ontologies of systemicity – that invite the perceived need for ‘anticipatory governance’ and pervade contemporary urban theory and governance. This is exemplified, I argue, by two current trends in urban governance: the promotion of smart and resilient cities.

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Kedar, S., H. K. M. Tanaka, C. J. Naudet, C. E. Jones, J. P. Plaut, and F. H. Webb. "Muon radiography for exploration of Mars geology." Geoscientific Instrumentation, Methods and Data Systems Discussions 2, no. 2 (October 18, 2012): 829–53. http://dx.doi.org/10.5194/gid-2-829-2012.

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Abstract. Muon radiography is a technique that uses naturally occurring showers of muons (penetrating particles generated by cosmic rays) to image the interior of large scale geological structures in much the same way as standard X-ray radiography is used to image the interior of smaller objects. Recent developments and application of the technique to terrestrial volcanoes have demonstrated that a low-power, passive muon detector can peer deep into geological structures up to several kilometers in size, and provide crisp density profile images of their interior at ten meter scale resolution. Preliminary estimates of muon production on Mars indicate that the near horizontal Martian muon flux, which could be used for muon radiography, is as strong or stronger than that on Earth, making the technique suitable for exploration of numerous high priority geological targets on Mars. The high spatial resolution of muon radiography also makes the technique particularly suited for the discovery and delineation of Martian caverns, the most likely planetary environment for biological activity. As a passive imaging technique, muon radiography uses the perpetually present background cosmic ray radiation as the energy source for probing the interior of structures from the surface of the planet. The passive nature of the measurements provides an opportunity for a low power and low data rate instrument for planetary exploration that could operate as a scientifically valuable primary or secondary instrument in a variety of settings, with minimal impact on the mission's other instruments and operation.

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Kedar, S., H. K. M. Tanaka, C. J. Naudet, C. E. Jones, J. P. Plaut, and F. H. Webb. "Muon radiography for exploration of Mars geology." Geoscientific Instrumentation, Methods and Data Systems 2, no. 1 (June 17, 2013): 157–64. http://dx.doi.org/10.5194/gi-2-157-2013.

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Abstract. Muon radiography is a technique that uses naturally occurring showers of muons (penetrating particles generated by cosmic rays) to image the interior of large-scale geological structures in much the same way as standard X-ray radiography is used to image the interior of smaller objects. Recent developments and application of the technique to terrestrial volcanoes have demonstrated that a low-power, passive muon detector can peer deep into geological structures up to several kilometers in size, and provide crisp density profile images of their interior at ten meter scale resolution. Preliminary estimates of muon production on Mars indicate that the near horizontal Martian muon flux, which could be used for muon radiography, is as strong or stronger than that on Earth, making the technique suitable for exploration of numerous high priority geological targets on Mars. The high spatial resolution of muon radiography also makes the technique particularly suited for the discovery and delineation of Martian caverns, the most likely planetary environment for biological activity. As a passive imaging technique, muon radiography uses the perpetually present background cosmic ray radiation as the energy source for probing the interior of structures from the surface of the planet. The passive nature of the measurements provides an opportunity for a low power and low data rate instrument for planetary exploration that could operate as a scientifically valuable primary or secondary instrument in a variety of settings, with minimal impact on the mission's other instruments and operation.

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Willocks, A. J., and B. A. Simons. "Geologists and geophysicists: getting them on the same planet." Exploration Geophysics 29, no. 3-4 (September 1998): 658–64. http://dx.doi.org/10.1071/eg998658.

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Benatar, Solomon, Ross Upshur, and Stephen Gill. "Understanding the relationship between ethics, neoliberalism and power as a step towards improving the health of people and our planet." Anthropocene Review 5, no. 2 (March 2, 2018): 155–76. http://dx.doi.org/10.1177/2053019618760934.

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This article seeks to evaluate the ethical underpinnings of neoliberalism and its associated power relations, and to illustrate the influence of such relationships on the health of people and the planet in the so-called era of the Anthropocene. We seek to reveal the current ethical standing of neoliberalism, and to identify other ethical positions and power relations that could be more conducive to promoting peaceful progress in an era during which all future life on our planet will be increasingly threatened by several organically inter-linked, human-caused crises, including that of the Earth’s biosphere. We conclude that on a planet close to many tipping points, beyond which irreversible entropy may ensue, a shift is needed away from neoliberal and anthropocentric belief systems towards a more ecologically aware perspective on life. Fostering the ethics of greater cooperation, mutual respect, deeper democracy, solidarity and enhanced social justice could facilitate the development of sustainability as a maxim of wisdom and praxis. Ultimately however, such progress requires the transformation of political power, as well as policies that are grounded in new ethical commitments.

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Brack, André, Pascale Ehrenfreund, Günter von Kiedrowski, Helmut Lammer, Daniel Prieur, Ewa Szuszkiewicz, and Frances Westall. "EANA trail guide in astrobiology: search for a second genesis of life." International Journal of Astrobiology 4, no. 3-4 (October 2005): 195–202. http://dx.doi.org/10.1017/s1473550405002740.

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The European Astrobiology Network Association (EANA) coordinates and promotes astrobiology in the 17 European countries that are member of the organization. Astrobiology includes the study of the origin, evolution and distribution of life in the Universe. It is a multi-disciplinary science that encompasses the disciplines of chemistry, biology, palaeontology, geology, atmospheric physics, planetary physics and stellar physics. The open questions to be addressed and the steps ahead in cosmochemistry, star and planet formation, the chemistry of life's origin, the study of bacterial life as a reference and the search for habitats and biosignatures beyond the Earth are presented.

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McGlynn, Shawn E., Jennifer B. Glass, Kristin Johnson-Finn, Frieder Klein, Sebastian A. Sanden, Matthew O. Schrenk, Yuichiro Ueno, and Alberto Vitale-Brovarone. "Hydrogenation reactions of carbon on Earth: Linking methane, margarine, and life." American Mineralogist 105, no. 5 (May 1, 2020): 599–608. http://dx.doi.org/10.2138/am-2020-6928ccbyncnd.

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Abstract Hydrogenation reactions are a major route of electron and proton flow on Earth. Interfacing geology and organic chemistry, hydrogenations occupy pivotal points in the Earth’s global geochemical cycles. Some examples of hydrogenation reactions on Earth today include the production and consumption of methane in both abiotic and biotic reactions, the reduction of protons in hydrothermal settings, and the biological synthesis and degradation of fatty acids. Hydrogenation reactions were likely important for prebiotic chemistry on the early Earth, and today serve as one of the fundamental reaction classes that enable cellular life to construct biomolecules. An understanding and awareness of hydrogenation reactions is helpful for comprehending the larger web of molecular and material inter-conversions on our planet. In this brief review we detail some important hydrogenation and dehydrogenation reactions as they relate to geology, biology, industry, and atmospheric chemistry. Such reactions have implications ranging from the suite of reactions on early Earth to industrial applications like the production of hydrocarbon fuel.

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Dewey, J. F., E. S. Kiseeva, J. A. Pearce, and L. J. Robb. "Precambrian tectonic evolution of Earth: an outline." South African Journal of Geology 124, no. 1 (March 1, 2021): 141–62. http://dx.doi.org/10.25131/sajg.124.0019.

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Abstract Space probes in our solar system have examined all bodies larger than about 400 km in diameter and shown that Earth is the only silicate planet with extant plate tectonics sensu stricto. Venus and Earth are about the same size at 12 000 km diameter, and close in density at 5 200 and 5 500 kg.m-3 respectively. Venus and Mars are stagnant lid planets; Mars may have had plate tectonics and Venus may have had alternating ca. 0.5 Ga periods of stagnant lid punctuated by short periods of plate turnover. In this paper, we contend that Earth has seen five, distinct, tectonic periods characterized by mainly different rock associations and patterns with rapid transitions between them; the Hadean to ca. 4.0 Ga, the Eo- and Palaeoarchaean to ca. 3.1 Ga, the Neoarchaean to ca. 2.5 Ga, the Proterozoic to ca. 0.8 Ga, and the Neoproterozoic and Phanerozoic. Plate tectonics sensu stricto, as we know it for present-day Earth, was operating during the Neoproterozoic and Phanerozoic, as witnessed by features such as obducted supra-subduction zone ophiolites, blueschists, jadeite, ruby, continental thin sediment sheets, continental shelf, edge, and rise assemblages, collisional sutures, and long strike-slip faults with large displacements. From rock associations and structures, nothing resembling plate tectonics operated prior to ca. 2.5 Ga. Archaean geology is almost wholly dissimilar from Proterozoic-Phanerozoic geology. Most of the Proterozoic operated in a plate tectonic milieu but, during the Archaean, Earth behaved in a non-plate tectonic way and was probably characterised by a stagnant lid with heat-loss by pluming and volcanism, together with diapiric inversion of tonalite-trondjemite-granodiorite (TTG) basement diapirs through sinking keels of greenstone supracrustals, and very minor mobilism. The Palaeoarchaean differed from the Neoarchaean in having a more blobby appearance whereas a crude linearity is typical of the Neoarchaean. The Hadean was probably a dry stagnant lid Earth with the bulk of its water delivered during the late heavy bombardment, when that thin mafic lithosphere was fragmented to sink into the asthenosphere and generate the copious TTG Ancient Grey Gneisses (AGG). During the Archaean, a stagnant unsegmented, lithospheric lid characterised Earth, although a case can be made for some form of mobilism with “block jostling”, rifting, compression and strike-slip faulting on a small scale. We conclude, following Burke and Dewey (1973), that there is no evidence for subduction on a global scale before about 2.5 Ga, although there is geochemical evidence for some form of local recycling of crustal material into the mantle during that period. After 2.5 Ga, linear/curvilinear deformation belts were developed, which “weld” cratons together and palaeomagnetism indicates that large, lateral, relative motions among continents had begun by at least 1.88 Ga. The “boring billion”, from about 1.8 to 0.8 Ga, was a period of two super-continents (Nuna, also known as Columbia, and Rodinia) characterised by substantial magmatism of intraplate type leading to the hypothesis that Earth had reverted to a single plate planet over this period; however, orogens with marginal accretionary tectonics and related magmatism and ore genesis indicate that plate tectonics was still taking place at and beyond the bounds of these supercontinents. The break-up of Rodinia heralded modern plate tectonics from about 0.8 Ga. Our conclusions are based, almost wholly, upon geological data sets, including petrology, ore geology and geochemistry, with minor input from modelling and theory.

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de Mulder, Eduardo F. J., Ted Nield, and Edward Derbyshire. "The International Year of Planet Earth (2007–2009): Earth Sciences for Society." Leading Edge 26, no. 10 (October 2007): 1302–4. http://dx.doi.org/10.1190/1.2794392.

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Chan, Marjorie A., Brenda Beitler Bowen, W. T. Parry, Jens Ormö, and Goro Komatsu. "Red rock and red planet diagenesis: Comparisons of Earth and Mars concretions." GSA Today 15, no. 8 (2005): 4. http://dx.doi.org/10.1130/1052-5173(2005)015[4:rrarpd]2.0.co;2.

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Chan, Marjorie A., Brenda Beitler Bowen, W. T. Parry, Jens Ormö, and Goro Komatsu. "Red rock and red planet diagenesis: Comparisons of Earth and Mars concretions." GSA Today 15, no. 8 (2005): 4. http://dx.doi.org/10.1130/1052-5173(2005)15[4:rrarpd]2.0.co;2.

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De Sanctis, Maria Cristina, and Eleonora Ammannito. "Organic Matter and Associated Minerals on the Dwarf Planet Ceres." Minerals 11, no. 8 (July 22, 2021): 799. http://dx.doi.org/10.3390/min11080799.

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Ceres is the largest object in the main belt and it is also the most water-rich body in the inner solar system besides the Earth. The discoveries made by the Dawn Mission revealed that the composition of Ceres includes organic material, with a component of carbon globally present and also a high quantity of localized aliphatic organics in specific areas. The inferred mineralogy of Ceres indicates the long-term activity of a large body of liquid water that produced the alteration minerals discovered on its surface, including ammonia-bearing minerals. To explain the presence of ammonium in the phyllosilicates, Ceres must have accreted organic matter, ammonia, water and carbon present in the protoplanetary formation region. It is conceivable that Ceres may have also processed and transformed its own original organic matter that could have been modified by the pervasive hydrothermal alteration. The coexistence of phyllosilicates, magnetite, carbonates, salts, organics and a high carbon content point to rock–water alteration playing an important role in promoting widespread carbon occurrence.

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Brice, William. "Henry Shaler Williams (1847-1918) and Punctuated Equilibria." Earth Sciences History 23, no. 1 (January 1, 2004): 32–40. http://dx.doi.org/10.17704/eshi.23.1.x65364304270hk08.

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From the first realization that organic life on this planet has evolved over geologic time, scientists have speculated about the time interval required for these changes to occur. For many years Darwin's idea of slow incremental changes, gradualism, was the accepted model. In the 1970s Stephen Gould (1941-2002) and Niles Eldridge (b. 1943) provided an alternative model of very rapid evolutionary change, followed by long periods of stability, which they called punctuated equilibria. It now appears that Henry Shaler Williams, a geology professor at Cornell University, arrived at the same interpretation almost one hundred years earlier, but only stated this belief in his class lecture notes. He, like Gould and Eldridge, noticed that the fossil record provides evidence that organisms evolved by very fast physical changes occurring in only a few generations and in a very short geological time interval. Then the organisms appear to undergo almost no change for long periods of time; i.e., long periods of stability through many generations. Exactly why Williams did not produce a formal publication of his concept remains a mystery, but his lecture notes from the early 1880s clearly demonstrate that he had developed the idea of punctuated equilibria.

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Misener, William, and Hilke E. Schlichting. "To cool is to keep: residual H/He atmospheres of super-Earths and sub-Neptunes." Monthly Notices of the Royal Astronomical Society 503, no. 4 (March 27, 2021): 5658–74. http://dx.doi.org/10.1093/mnras/stab895.

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ABSTRACT Super-Earths and sub-Neptunes are commonly thought to have accreted hydrogen/helium envelopes, consisting of a few to ten percent of their total mass, from the primordial gas disc. Subsequently, hydrodynamic escape driven by core-powered mass-loss and/or photoevaporation likely stripped much of these primordial envelopes from the lower mass and closer-in planets to form the super-Earth population. In this work, we show that after undergoing core-powered mass-loss, some super-Earths can retain small residual H/He envelopes. This retention is possible because, for significantly depleted atmospheres, the density at the radiative–convective boundary drops sufficiently such that the cooling time-scale becomes shorter than the mass-loss time-scale. The residual envelope is therefore able to contract, terminating further mass-loss. Using analytic calculations and numerical simulations, we show that the mass of primordial H/He envelope retained as a fraction of the planet’s total mass, fret, increases with increasing planet mass, Mc, and decreases with increasing equilibrium temperature, Teq, scaling as $f_\mathrm{ret} \propto M_\mathrm{c}^{3/2} T_\mathrm{eq}^{-1/2} \exp {[M_\mathrm{c}^{3/4} T_\mathrm{eq}^{-1}]}$. fret varies from <10−8 to about 10−3 for typical super-Earth parameters. To first order, the exact amount of left-over H/He depends on the initial envelope mass, the planet mass, its equilibrium temperature, and the envelope’s opacity. These residual hydrogen envelopes reduce the atmosphere’s mean molecular weight compared to a purely secondary atmosphere, a signature observable by current and future facilities. These remnant atmospheres may, however, in many cases be vulnerable to long-term erosion by photoevaporation. Any residual hydrogen envelope likely plays an important role in the long-term physical evolution of super-Earths, including their geology and geochemistry.

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TERASAKI, Hidenori. "Percolative core formation model in planet interiors." Japanese Magazine of Mineralogical and Petrological Sciences 38, no. 1 (2009): 9–12. http://dx.doi.org/10.2465/gkk.38.9.

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Tagliacozzo, Eric. "Borneo in Fragments: Geology, Biota, and Contraband in Trans-national Circuits." TRaNS: Trans -Regional and -National Studies of Southeast Asia 1, no. 1 (January 2013): 63–85. http://dx.doi.org/10.1017/trn.2012.8.

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AbstractIn the second half of the nineteenth century, Borneo – supposedly one of the most isolated islands on the planet – became a trans-national site of growing importance. Instead of being imagined as a site of endless forests, inaccessible mountains, and undisturbed nature, Borneo became a place to extract and move objects, many of them spinning off into international circuits. The British and Dutch, who became the dual colonial overlords of the island, became the primary actors in facilitating these movements. Yet Asian actors – such as the Chinese, Malays, and various Dayak peoples – also were heavily involved in these transits. The first part of this essay looks at the role of geology and minerals in effecting these transitions. The second part of the paper examines the movement of biota, especially vis-a-vis Chinese networks, in connecting Borneo to other shores. Finally, the third part of the essay looks at contraband cargoes of diverse origins in also facilitating these connections. I argue that far from being an isolated and ‘off-the-beaten-track’ locale, Borneo became central to new ideas of trans-national connection in Southeast Asia, linking people, commodities, and trade circuits into an ever-tightening embrace.

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Shatalov, N. N. "PAVLO STEFANOVICH VORONOV — OUTSTANDING POLAR GEOLOGIST (to the 100th anniversary of birth)." Geology and Mineral Resources of World Ocean 16, no. 4 (2020): 49–63. http://dx.doi.org/10.15407/gpimo2020.04.049.

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The article is dedicated to the outstanding geologist-polar explorer of the USSR, an outstanding naturalist, doctor of geological and mineralogical sciences, Professor Pavel Voronov in the light of 100th anniversary of his birth celebration. The main stages of the scientist’s life, his achievements in studying the geology of a lot of regions of the Arctic Ocean are considered. The contribution of the scientist to the research of geology, tectonics, geography, geomorphology and glaciology of the southern hemisphere of our planet was especially noted. In the 40th-50th years of the last century P.S. Voronov participated in the work of the first and second Russian expeditions in Antarctica. The scientist carried out reconnaissance geological and geomorphological studies of the observatory area, the Bunger oasis, based on hydrographic measurements from the board of the expeditionary vessel «Ob» and analysis of the configuration of the Antarctic coast, for the first time in the world, he established the existence of coastal faults located around East Antarctica. Numerous flights on IL-12 aircraft allowed P.S. Voronov to explore the mountain ranges of Antarctica along the Antarctic Circle. He clarified the position of the Denman glacier and carried out comprehensive geological, geomorphological and tectonic studies in Antarctica. On various issues of geology, geomorphology, glaciology and tectonics of Antarctica, he published more than 60 scientific papers, many of which are pioneering and have retained their relevance to the present day. Professor P.S. Voronov is widely known in the former USSR and abroad for his research in the field of space and geodynamics, tectonics and planetary geomorphology of the Earth’s continents and sea areas. Scientist has written more than 250 scientific works, including 12 monographs. His main works reveal questions about the patterns of morphometry of the Earth’s global relief, the role of the Earth’s rotational forces, the principles and role of shear tectonics in the structure of the Earth’s lithospheres and terrestrial planets. In 2004, the Cambridge International Biographical Center introduced the name of P.S. Voronov to the collection «Living Legends».

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Young, Terry. "Presidential Address: Our expanding sphere—grand challenges for planet Earth and for SEG." Leading Edge 26, no. 2 (February 2007): 202–8. http://dx.doi.org/10.1190/1.2711500.

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Shaller, Philip J., Macan Doroudian, and Michael W. Hart. "The Eureka Valley Landslide: Evidence of a Dual Failure Mechanism for a Long-Runout Landslide." Lithosphere 2020, no. 1 (December 2, 2020): 1–26. http://dx.doi.org/10.2113/2020/8860819.

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Abstract Long-runout landslides are well-known and notorious geologic hazards in many mountainous parts of the world. Commonly encompassing enormous volumes of debris, these rapid mass movements place populations at risk through both direct impacts and indirect hazards, such as downstream flooding. Despite their evident risks, the mechanics of these large-scale landslides remain both enigmatic and controversial. In this work, we illuminate the inner workings of one exceptionally well-exposed and well-preserved long-runout landslide of late Pleistocene age located in Eureka Valley, east-central California, Death Valley National Park. The landslide originated in the detachment of more than 5 million m3 of Cambrian bedrock from a rugged northwest-facing outcrop in the northern Last Chance Range. Its relatively compact scale, well-preserved morphology, varied lithologic composition, and strategic dissection by erosional processes render it an exceptional laboratory for the study of the long-runout phenomenon in a dry environment. The landslide in Eureka Valley resembles, in miniature, morphologically similar “Blackhawk-like” landslides on Earth, Mars, and minor planet Ceres, including the well-known but much larger Blackhawk landslide of southern California. Like these other landslides, the landslide in Eureka Valley consists of a lobate, distally raised main lobe bounded by raised lateral levees. Like other terrestrial examples, it is principally composed of pervasively fractured, clast-supported breccia. Based on the geologic characteristics of the landslide and its inferred kinematics, a two-part emplacement mechanism is advanced: (1) a clast-breakage mechanism (cataclasis) active in the bedrock canyon areas and (2) sliding on a substrate of saturated sediments encountered and liquefied by the main lobe of the landslide as it exited the main source canyon. Mechanisms previously hypothesized to explain the high-speed runout and morphology of the landslide and its Blackhawk-like analogs are demonstrably inconsistent with the geology, geomorphology, and mineralogy of the subject deposit and its depositional environment.

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Britvin, Sergey N., Michail N. Murashko, Yevgeny Vapnik, Natalia S. Vlasenko, Maria G. Krzhizhanovskaya, Oleg S. Vereshchagin, Vladimir N. Bocharov, and Maksim S. Lozhkin. "Cyclophosphates, a new class of native phosphorus compounds, and some insights into prebiotic phosphorylation on early Earth." Geology 49, no. 4 (November 20, 2020): 382–86. http://dx.doi.org/10.1130/g48203.1.

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Abstract Cyclophosphates are a class of energy-rich compounds whose hydrolytic decomposition (ring opening) liberates energy that is sufficient for initiation of biomimetic phosphorylation reactions. Because of that, cyclophosphates might be considered as a likely source of reactive prebiotic phosphorus on early Earth. A major obstacle toward adoption of this hypothesis is that cyclophosphates have so far not been encountered in nature. We herein report on the discovery of these minerals in the terrestrial environment, at the Dead Sea basin in Israel. Cyclophosphates represent the most condensed phosphate species known in nature. A pathway for cyclophosphate geosynthesis is herein proposed, involving simple pyrolytic oxidation of terrestrial phosphides. Discovery of natural cyclophosphates opens new opportunities for modeling prebiotic phosphorylation reactions that resulted in the emergence of primordial life on our planet.

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Volyanskaya, Viktoria V. "New G&G Technology Pilot testing and verification: Methodological Recommendations." Georesursy 23, no. 2 (May 25, 2021): 192–96. http://dx.doi.org/10.18599/grs.2021.2.19.

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Development of computer technologies allows not only to optimize the process of geological study of our planet, but also to create fundamentally new approaches in working with large arrays of geological data. This led to the transition of formalization of geological knowledge and information from the descriptive form to the technological one, i.e. aimed at the industrial application of unified approaches. The article explains the concept of “technology” as applied to the Earth sciences (“G&G-technology” – Geology & Geophysics Technology). The example of direct and reverse algorithm of hydrocarbon deposits study is given. Stages of new G&G-technologies creation and change of information content level at each stage of this process bring forward certain requirements when selecting geological objects for testing and verification of the obtained result. The practical example of set of criteria for verification of fracture zones mapping technology is considered and the importance of balance between theoretical, methodological and practical elements of mineral deposits study and modeling is described.

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Ribeiro, Tiago. "Integrar a história da ciência na sala de aula através de um caso: o papel de Lyell no desenvolvimento dos trabalhos de Darwin." História da Ciência e Ensino: construindo interfaces 20 (December 18, 2019): 52–62. http://dx.doi.org/10.23925/2178-2911.2019v20p52-62.

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Resumo No século XIX, o desenvolvimento científico ficou marcado por uma grande restruturação concetual: a perceção da existência de um longo período de tempo, anterior e independente à presença do Homem na Terra. Os trabalhos de Lyell foram particularmente responsáveis pela evolução desta corrente ideológica. Este uniformitarista, através da observação de pequenas mudanças terrestres subtis à escala humana (mas expressivas quando analisadas à luz de milhões de anos), contribuiu para compreensão dos fenómenos geológicos. Contudo, esta ideologia não se refletiu apenas na geologia. Quando Darwin, em 1831, partiu no Beagle, tinha consigo o livro “Principles of Geology” de Lyell. Sensibilizado pelas suas ideias, e consciente das transformações graduais do planeta, Darwin desenvolveu várias noções que viriam a ser incluídas no evolucionismo. As ideias de Lyell, articuladas com uma escala geológica ao invés de histórica, foram preponderantes para a existência de um “outro” tempo coerente com a transmutação das espécies. O uniformitarismo foi, então, basilar para a criação de um contexto favorável à recetividade da teoria de Darwin, evidenciando a importância de um pensamento interdisciplinar e holístico na ciência. Pretende-se, neste trabalho, reforçar a relevância deste tipo de pensamento no ensino das ciências naturais. Para tal, elaborou-se um recurso educativo, segundo a metodologia de ensino baseado em casos, com a finalidade de facilitar a inclusão da história da ciência no ensino. Palavras-chave: Uniformitarismo, Evolucionismo, História da Ciência. Abstract In the nineteenth century, scientific development was marked by a great conceptual restructuring: the perception of the existence of a long time, prior and independent to the presence of Man on Earth. Lyell's works were particularly responsible for the evolution of this ideological current. Lyell, through the observation of subtle Earth changes on the human scale (but expressive when analysed in the enlightenment of millions of years), contributed to understanding geological phenomena. However, this ideology was not only reflected in geology. When Darwin, in 1831, embarked on the Beagle, he had the Lyell's book "Principles of Geology". Induced by his ideas, and conscious of the gradual transformations of the planet, Darwin developed several notions that were included in the evolutionism. Lyell's ideas, articulated with a geological rather than a historical scale, were preeminent for the existence of an "other" time consistent with the transmutation of species. The uniformitarianism was, then, essential for the creation of a context favourable to the receptivity of Darwin’s theory, evidencing the importance of an interdisciplinary and holistic thinking in the science. In this work, it is intent to reinforce the relevance of this type of thinking in the natural sciences’ teaching. Thus, an educational resource was elaborated, according to the case-based teaching methodology, with the purpose of facilitating the inclusion of the history of science in teaching process. Keywords: Uniformitarianism, Evolutionism, History of Science.

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Vitaliano, Dorothy B. "Tales of the Earth: Paroxysms and Perturbations of the Blue Planet. Charles Officer , Jake Page." Journal of Geology 102, no. 1 (January 1994): 117. http://dx.doi.org/10.1086/629652.

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KAZANTSEVA, T. T. "TO STRATIGRAPHY AND GEODYNAMICS ZILAIR SEDIMENTS IN THE SOUTHERN URALS." Izvestia Ufimskogo Nauchnogo Tsentra RAN, no. 3 (September 30, 2021): 77–88. http://dx.doi.org/10.31040/2222-8349-2021-0-3-77-88.

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It is known that the upper shell of our planet is the earth's crust, which is different in composition on the continents and in the oceans. The composition of the continental crust is predominantly sialic, and the oceanic one is simatic. The capacity of the first is within 35-70 km, the second is close to 5-12. The formation of any type of the earth's crust is determined by the participation of specific geological processes, causal relationships of matter and geodynamics, which is justified by researchers on the basis of well-proven facts and judgments. The concepts used must be specific, in accordance with well-known definitions, such as: stratigraphy is a branch of geology that studies «the formation of rocks in their primary spatial relationships», and geodynamics is «a branch of geology that studies the forces and processes in the crust, mantle and core of the Earth, deep and surface movements of masses in time and space» [1]. The use of the conceptual framework and the study of numerous facts allow us to confidently identify the sequence of connections and the reasons for the relationship.

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Stewart, Iain S., and Victoria Hurth. "Selling planet Earth: re-purposing geoscience communications." Geological Society, London, Special Publications 508, no. 1 (2021): 265–83. http://dx.doi.org/10.1144/sp508-2020-101.

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AbstractEarth scientists have a critical role to play in communicating to the public and policy makers what we know about present and future geo-environmental threats and challenges, such as climate change, extreme natural events, resource conflicts and the energy transition. However, whilst geoscientists are being encouraged – and, increasingly, trained – to ‘go public’ with our science, it is less clear to what extent our current geo-communications are effectively addressing the long-term planetary concerns that confront society. In this paper we argue that scientists are the interface between the research organizations that produce knowledge and the wider public who could use that knowledge, and in that regard are akin to marketers in the business world. Drawing from the dominant paradigms that shape business marketing, we re-consider the prevailing models of science communication and their consequent sense of purpose. We identify three dominant approaches of marketing-led science communication: ‘make-and-sell’; ‘sense-and-respond’; and ‘guide-and-co-create’. We judge the first two to be incompatible with delivering long-term sustainability, in contrast to the emergent guide-and-co-create mode – purpose-driven, interdisciplinary, participatory, and reflexive – which we contend is best placed to tackle long-term geo-environmental concerns through having a clear wellbeing-focused objective whilst co-creating the path to achieving it. We conclude with the contention that adopting a guide-and-co-create approach to science communications will require not only re-thinking of communication practice within universities but also radical institutional regime change towards universities becoming purpose-driven organizations.

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Nabert, Christian, Daniel Heyner, and Karl-Heinz Glassmeier. "Estimation of a planetary magnetic field using a reduced magnetohydrodynamic model." Annales Geophysicae 35, no. 3 (March 22, 2017): 465–74. http://dx.doi.org/10.5194/angeo-35-465-2017.

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Abstract. Knowledge of planetary magnetic fields provides deep insights into the structure and dynamics of planets. Due to the interaction of a planet with the solar wind plasma, a rather complex magnetic environment is generated. The situation at planet Mercury is an example of the complexities occurring as this planet's field is rather weak and the magnetosphere rather small. New methods are presented to separate interior and exterior magnetic field contributions which are based on a dynamic inversion approach using a reduced magnetohydrodynamic (MHD) model and time-varying spacecraft observations. The methods select different data such as bow shock location information or magnetosheath magnetic field data. Our investigations are carried out in preparation for the upcoming dual-spacecraft BepiColombo mission set out to precisely estimate Mercury's intrinsic magnetic field. To validate our new approaches, we use THEMIS magnetosheath observations to estimate the known terrestrial dipole moment. The terrestrial magnetosheath provides observations from a strongly disturbed magnetic environment, comparable to the situation at Mercury. Statistical and systematic errors are considered and their dependence on the selected data sets are examined. Including time-dependent upstream solar wind variations rather than averaged conditions significantly reduces the statistical error of the estimation. Taking the entire magnetosheath data along the spacecraft's trajectory instead of only the bow shock location into account further improves accuracy of the estimated dipole moment.

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Sun, Wei, Jian Wang, JinRu Chen, Ying Wang, GuangMing Yu, and XianHai Xu. "Contrast analysis between the trajectory of the planetary system and the periodicity of solar activity." Annales Geophysicae 35, no. 3 (May 17, 2017): 659–69. http://dx.doi.org/10.5194/angeo-35-659-2017.

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Abstract. The relationship between the periodic movement of the planetary system and its influence on solar activity is currently a serious topic in research. The kinematic index of the planet juncture index has been developed to find the track and variation of the Sun around the centroid of the solar system and the periodicity of solar activity. In the present study, the kinematic index of the planetary system's heliocentric longitude, developed based on the orbital elements of planets in the solar system, and it is used to investigate the periodic movement of the planetary system. The kinematic index of the planetary system's heliocentric longitude and that of the planet juncture index are simulated and analyzed. The numerical simulation of the two kinematic indexes shows orderly orbits and disorderly orbits of 49.9 and 129.6 years, respectively. Two orderly orbits or two disorderly orbits show a period change rule of 179.5 years. The contrast analysis between the periodic movement of the planetary system and the periodicity of solar activity shows that the two phenomena exhibit a period change rule of 179.5 years. Moreover, orderly orbits correspond to high periods of solar activity and disorderly orbits correspond to low periods of solar activity. Therefore, the relative movement of the planetary system affects solar activity to some extent. The relationship provides a basis for discussing the movement of the planetary system and solar activity.

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Williams, David A., T. Kneissl, A. Neesemann, S. C. Mest, E. Palomba, T. Platz, A. Nathues, et al. "The geology of the Kerwan quadrangle of dwarf planet Ceres: Investigating Ceres’ oldest, largest impact basin." Icarus 316 (December 2018): 99–113. http://dx.doi.org/10.1016/j.icarus.2017.08.015.

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Byrne, Paul K., Richard C. Ghail, Martha S. Gilmore, A. M. Celâl Şengör, Christian Klimczak, David A. Senske, Jennifer L. Whitten, Sara Khawja, Richard E. Ernst, and Sean C. Solomon. "Venus tesserae feature layered, folded, and eroded rocks." Geology 49, no. 1 (September 4, 2020): 81–85. http://dx.doi.org/10.1130/g47940.1.

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Abstract Tesserae on Venus are locally the stratigraphically oldest units preserved on the planet. These regions are characterized by pervasive tectonic deformation including normal faults, grabens, thrust faults, and folds. In multiple tesserae, sets of (often highly) curved, parallel linear features are also present. These features strongly resemble terracing in layered volcanic or sedimentary sequences on Earth having arcuate or sinuous outcrop patterns that follow undulating topography. Should this analogy hold for Venus, then these outcrop patterns imply some erosion of the tessera units in which these strata occur; radar-dark materials filling proximal lows might be deposits of that eroded material. This outcrop pattern is seen in geographically dispersed tessera units, so the preservation of layering could be common for this terrain type. If so, then tesserae record the culmination of volcanic and/or sedimentary deposition, folding, and erosion—complex geological histories that should be considered in future studies of this enigmatic terrain.

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Journal articles on the topic 'Planet geology'

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