Cartographic Representation of Channel Forms on Planetary Geologic Maps

2020 ◽  
Author(s):  
Henrik Hargitai
Keyword(s):  
Narrow Channels ◽  
Drainage Networks ◽  
Ongoing Work ◽  
Scale Line ◽  
Outflow Channels ◽  
Geologic Maps ◽  
History Of ◽  
Valley Network ◽  
Map Scale ◽  
Blue Line

<p> </p><p>Channel morphologies are sinuous, negative-relief linear forms that form by a current of water or lava. They may be fluvial or volcanic in origin. Channels are exclusively volcanic on Venus, volcanic or fluvial on Mars and fluvial on Titan. On Venus and Mars, channels are all paleoforms while on Titan (and Earth) they are actively forming. Channels may be hosted by valleys, that represent the cumulative erosional history of the embedded channel. They may be singular or may form braided pattern separated by streamlined island forms (e.g., Kasei Valles); a channel floor may host interior channels (e.g., Navua Valles), and channels may disappear gradually into flat plains (e.g., Simud Vallis). These are just a few of their characteristics that make their cartographic representation a complex issue.</p><p>In this work we analyzed and compared the symbology of channel forms in planetary geologic maps. An ongoing work on planetary geologic symbology identified 95 maps containing channel symbols in a total of 154 map (Nass et al. 2017b). Symbology is important for several reasons (Nass et al. 2011, Nass et al. 2017a). Although each map is complete on its own, standardized symbology enables direct comparison between maps. Maps are used for measurements: channel morphometry measurements across different quadrangles become problematic if symbols are used and defined differently.</p><p>Planetary geologic maps use three classes of symbols for representing channel forms: polygons as geologic units, polygons as surficial units laid over a geologic unit and line symbols for smaller channels. Line symbols often transform to geologic units when they reach a cutoff size for the used map scale. Line symbols do not continue over the unit symbols. This way drainage networks are split into two, incompatible symbol types. The cutoff size is often not reported in the legend that use the vague "narrow channels" designation for the line symbols. Sometimes line symbols are used only for "small distributary channels" or "small valleys".</p><p>Named channel units may be grouped geographically (e.g., Ares Vallis), by age (e.g., Hesperian channels), by morphology (steep walled channels), process (outflow channels) or as true geologic units (vallis floor sediments). These categories may be even mixed within one map.</p><p>The line symbols are typically solid blue (cyan) lines. This is in accordance with FGDC standards (FGDC 2006).</p><p>Different problems arise with drainage databases (Hynek et al. 2010, Alemanno et al. 2018). They typically uniformly trace dendritic valley networks, but they also contain singular and other channel forms, whereas "outflow channels" and lava channels are missing from these databases. The global map of Tanaka et al. (2014) uses two different blue line symbols for "channel axis" (i.e., valley network and some outflow-like channels) and "outflow channels".</p><p>It is needed to redefine channel form classification in the planetary domain and symbology (from Venus to Mars to Titan) and make it clear for mappers if different symbols should be used for different sizes, origins, and morphologies and how different symbols may be combined in one map.</p><p> </p>

scholarly journals The fluvial history of Mars

2012 ◽  
Vol 370 (1966) ◽  
pp. 2193-2215 ◽  
Author(s):  
Michael H. Carr
Keyword(s):  
Climatic Conditions ◽  
River Channels ◽  
Erosion And Deposition ◽  
Running Water ◽  
The Earth ◽  
Outflow Channels ◽  
History Of ◽  
Valley Networks ◽  
River Valleys ◽  
Steep Slopes

River channels and valleys have been observed on several planetary bodies in addition to the Earth. Long sinuous valleys on Venus, our Moon and Jupiter's moon Io are clearly formed by lava, and branching valleys on Saturn's moon Titan may be forming today by rivers of methane. But by far the most dissected body in our Solar System apart from the Earth is Mars. Branching valleys that in plan resemble terrestrial river valleys are common throughout the most ancient landscapes preserved on the planet. Accompanying the valleys are the remains of other indicators of erosion and deposition, such as deltas, alluvial fans and lake beds. There is little reason to doubt that water was the erosive agent and that early in Mars' history, climatic conditions were very different from the present cold conditions and such that, at least episodically, water could flow across the surface. In addition to the branching valley networks, there are large flood features, termed outflow channels. These are similar to, but dwarf, the largest terrestrial flood channels. The consensus is that these channels were also cut by water although there are other possibilities. The outflow channels mostly postdate the valley networks, although most are still very ancient. They appear to have formed at a time when surface conditions were similar to those that prevail today. There is evidence that glacial activity has modified some of the water-worn valleys, particularly in the 30–50° latitude belts, and ice may also be implicated in the formation of geologically recent, seemingly water-worn gullies on steep slopes. Mars also has had a long volcanic history, and long, sinuous lava channels similar to those on the Moon and Venus are common on and around the large volcanoes. These will not, however, be discussed further; the emphasis here is on the effects of running water on the evolution of the surface.

The police invention of humanity: Notes on the “thin blue line”

2019 ◽  
Vol 16 (3) ◽  
pp. 319-336 ◽  
Author(s):  
Tyler Wall
Keyword(s):  
Human Existence ◽  
Police Power ◽  
Human Species ◽  
The Core ◽  
History Of ◽  
Racialized Violence ◽  
Blue Line ◽  
Security Property ◽  
As If ◽  
Sylvia Wynter

This article unpacks the idea of police as a “thin blue line” as narrating a story about the police invention of the human through a civilizing and exterminating war against beasts. To speak in the name of the “thin blue line,” then, is to articulate the police as the primary force which secures, or makes possible, all the things said to be at the core of “human” existence: liberty, security, property, sociality, accumulation, law, civility, and even happiness. The current project is less a history of the thin blue line slogan than a more conceptually grounded sketch, and abolitionist critique, of its most basic premises: the idea at the heart of thin blue line is that the most routine mode of violent state prerogative—the police power—is imagined as always a defense of civilization, which at once means the “human species.” In other words, thin blue line, to use a formulation from Sylvia Wynter, is best understood as a defense of a particular genre of the human, or “Man,” that “overrepresents itself as if it were the human itself.” But importantly, thin blue line articulates this police project of inventing the human as always incomplete, insecure, and unstable. Of course, it must always be incomplete, because it is through its inability to fully eradicate the bestial trace that police claim a license to endless war in the name of humanity. As a discourse of ordinary emergency, thin blue line becomes an expression of what Diren Valayden outlines as “racial feralization,” or the colonial bourgeois anxiety that humanity will regress back into a violent nature. A critique of the thin blue line encourages a consideration of how fantasies and failures of becoming human animate all things police, including the racialized violence at the heart of the police project.

Dynamicity and dialogue

2016 ◽  
Vol 9 (1) ◽  
pp. 56-76
Author(s):  
J. Lachlan Mackenzie
Keyword(s):  
Language Production ◽  
Language Use ◽  
Functional Grammar ◽  
Ongoing Work ◽  
Communicative Process ◽  
History Of ◽  
Discourse Grammar ◽  
The Impact ◽  
Static Nature

The article surveys how Functional Discourse Grammar (FDG; Hengeveld & Mackenzie 2008) has responded to Simon Dik’s call for a functional grammar to have ‘psychological adequacy’ and draws parallels to similar initiatives from other approaches. After a brief history of what has later come to be known as cognitive adequacy, the impact of psycholinguistic notions on the architecture of FDG is discussed and exemplified with emphasis on how FDG confronts the tension between the static nature of a pattern model of grammar and the dynamicity of the communicative process. The article then turns to four ways in which FDG has responded in recent years to ongoing work in psycholinguistics. The first concerns how the incrementality of language production, i.e. the gradual earlier-to-later build-up of utterances, has inspired FDG’s coverage of fragmentary discourse acts and its Depth-First Principle. The second, pertaining to the role of prediction in language comprehension, is reflected in the countdown to a clause-final position PF. The third is priming, involving the reuse of elements of structure at all levels of analysis: this interferes with the mapping of function onto form in ways that have been explored in FDG. The fourth is dialogical alignment, the manner in which participants in dialogue mutually accommodate their language use; this has led to new understandings of the respective roles of FDG’s Conceptual and Contextual Components. Taken together, these developments have moved FDG towards modelling dialoguing interactants rather than an isolated speaker.

EARLY REFLECTION SEISMOGRAPH EXPLORATION IN CALIFORNIA

Geophysics ◽  
1945 ◽  
Vol 10 (1) ◽  
pp. 17-33
Author(s):  
Henry Salvatori
Keyword(s):  
Correlation Method ◽  
Structural Features ◽  
Oil Fields ◽  
Limited Applicability ◽  
First Results ◽  
Geologic Maps ◽  
History Of ◽  
Well Data ◽  
Made In

The first major attempt to employ the reflection method in California was made in 1931. The first results were disappointing, but by the early part of 1932 a prospect near Merced was successfully mapped. The correlation method was found to have limited applicability and the dip method was generally adopted. Most of the early work was performed with wide spacing of stations and lines since very close control was not considered necessary to discover the larger structural features which were then of greatest interest. As a result of this early reflection work several important oil fields were discovered among which are the Wilmington and Rio Bravo fields. A brief history of the discovery of these two fields is given and the seismic maps are compared with the later geologic maps compiled from well data.

Structural history of the Manitouwadge greenstone belt and its volcanogenic Cu-Zn massive sulphide deposits, Wawa subprovince, south-central Superior Province

1999 ◽  
Vol 36 (4) ◽  
pp. 605-625 ◽  
Author(s):  
Virginia L Peterson ◽  
Eva Zaleski
Keyword(s):  
Base Metal ◽  
Greenstone Belt ◽  
Regional Metamorphism ◽  
Massive Sulphide ◽  
Iron Formation ◽  
Deformation History ◽  
South Central ◽  
Structural History ◽  
History Of ◽  
Map Scale

Structural analysis of the Manitouwadge greenstone belt, integrated with detailed mapping and geochronological and petrographic studies, reveals a complex early deformation history that significantly modified the primary distribution of base-metal deposits and alteration zones. The (D3) Manitouwadge synform dominates the map pattern; however, penetrative fabric development and establishment of the tectono-stratigraphy of base-metal deposits mostly predated D3. The D1 Garnet Lake fault, which repeats mineralized horizons within a distinctive lithological sequence, is delineated locally by annealed mylonite. D1 planar fabrics are preserved locally in outcrop and thin section. D2 folding accompanied peak regional metamorphism at upper amphibolite facies. The F2 Agam Lake syncline repeats the volcanic sequence across the southern limb of the Manitouwadge synform. A map-scale F2 sheath fold deforms the Garnet Lake fault. Minor D2 structures include prevalent outcrop-scale folds, locally with sheath geometry, the dominant S2 foliation, and mineral lineations (parallel to fold axes). Northwest-southeast-directed D3 shortening produced the Manitouwadge synform and related regional folds without extensive penetrative fabric development. Flexural slip folding is evident in the inner hinge of the synform where rocks of differing competency are interlayered. Higher strain, stronger fabric development, and a component of simple shear were preferentially partitioned to fold limbs. Relative pre-D3 structural geometries in the inner hinge region of the Manitouwadge synform are not significantly complicated by D3 and younger deformation. Retrodeformation of the mineralized sequence shows systematic stratigraphic patterns in iron formation types, stacked massive sulphide orebodies, and alteration types that can be applied to exploration models.

scholarly journals FROM THE HISTORY OF ECONOMIC DEVELOPMENT OF KAZAKHSTAN AFTER THE CIVIL WAR (1920-1924)

2020 ◽  
Vol 65 (2) ◽  
Author(s):  
B.S. Zhumagulov ◽  
Keyword(s):  
Economic Development ◽  
Civil War ◽  
Social Life ◽  
Economic Life ◽  
Demographic Situation ◽  
Ongoing Work ◽  
The Social ◽  
History Of ◽  
The Republic ◽  
Political Economic

The article analyzes a new view of the history of economic development of Kazakhstan after the civil war. The purpose of the work is to identify problems, analyze the implementation of the social and economic policy of Soviet power. In this article, there are new transformations in the political, economic and social life of Kazakhstan and the difficulties in its implementation. The ongoing work on restoration of peaceful life, destroyed economy and economy in Kazakhstan is indicated. The reasons for the decline in economic life, destruction, poverty and hunger in Kazakhstan are indicated. As a result of hunger, cold and the accompanying diseases, the demographic situation in the nomadic and semi-nomadic regions of the republic deteriorated – the population of the rural population in many provinces decreased to 1/3, more than 700 000 people left Kazakhstan.

scholarly journals Applying Indigenizing Principles of Decolonizing Methodologies in University Classrooms

2017 ◽  
Vol 47 (3) ◽  
pp. 16-33 ◽  
Author(s):  
Dustin William Louie ◽  
Yvonne Poitras-Pratt ◽  
Aubrey Jean Hanson ◽  
Jacqueline Ottmann
Keyword(s):  
Ways Of Knowing ◽  
Indigenous Students ◽  
Leading Role ◽  
Decolonizing Methodologies ◽  
Institutions Of Higher Learning ◽  
Ongoing Work ◽  
History Of ◽  
Indigenous Ways Of Knowing ◽  
Faculties Of Education ◽  
University Classrooms

This case study examines ongoing work to Indigenize education programs at one Canadian university. The history of the academy in Canada has been dominated by Western epistemologies, which have devalued Indigenous ways of knowing and set the grounds for continued marginalization of Indigenous students, communities, cultures, and histories. We argue that institutions of higher learning need to move away from the myopic lens used to view education and implement Indigenizing strategies in order to counteract the systemic monopolization of knowledge and communication. Faculties of education are taking a leading role in Canadian universities by hiring Indigenous scholars and incorporating Indigenous ways of knowing into teacher education courses. Inspired by the 25 Indigenous principles outlined by Maōri scholar Linda Tuhiwai Smith (2012), four Indigenous faculty members from Western Canada document effective decolonizing practices for classroom experience, interaction, and learning that reflect Indigenous values and orientations within their teaching practices.

The History of Septuagint Studies

2021 ◽  
pp. 51-70
Author(s):  
Felix Albrecht
Keyword(s):  
Critical Editions ◽  
Ongoing Work ◽  
Or Groups ◽  
Text Types ◽  
History Of

The editorial history of the Septuagint goes back to antiquity and is essentially connected with the emergence of the Septuagint itself, i.e. with the concept of Alexandrian ekdosis. However, this chapter focuses principally on the development of printed scholarly editions (both diplomatic and critical) up to the present day, and the principles on which they are based. Among other tasks, this involves noting scribal changes, both intentional and unintended; and the identification and reconstruction of text types or groups and the stages of transmission. The difficult process of producing critical editions of each book of the Septuagint corpus is ongoing work within the project of the Göttingen Septuaginta Unternehmen.

scholarly journals Influence of salt in the tectonic development of the frontal thrust belt of the eastern Cordillera (Guatiquía area, Colombian Andes)

2015 ◽  
Vol 3 (4) ◽  
pp. SAA17-SAA27 ◽  
Author(s):  
Vanessa Parravano ◽  
Antonio Teixell ◽  
Andrés Mora
Keyword(s):  
Structural Model ◽  
Salt Tectonics ◽  
Thrust Belt ◽  
Eastern Cordillera ◽  
Salt Migration ◽  
Colombian Andes ◽  
Kinematic Evolution ◽  
Geologic Maps ◽  
History Of ◽  
Tectonic Development

Geologic maps, seismic lines, and data from a dry exploration well were used to develop a new structural model for a segment of the eastern foothills of the Eastern Cordillera of Colombia, emphasizing the role of salt tectonics. Milestones in the deformation history of the Guatiquía foothills were studied by sequential section restoration to selected steps. Uncommon structural geometries and sparse salt occurrences were interpreted in terms of a kinematic evolution in which Cretaceous salt migration in extension produced a diapiric salt wall, which was subsequently welded during the main episodes of the Andean compression, when the salt wall was squeezed generating a large overturned flap. Salt-weld strain hardening resulted in breakthrough thrusting across the overturned flap in late deformation stages. We have evaluated a pattern of salt tectonics previously unrecognized in the foothills thrust belt, which may be significant in other parts of the external Colombian Andes.

Geologic Time

2021 ◽  
pp. 69-81
Author(s):  
Elisabeth Ervin-Blankenheim
Keyword(s):  
Time Scale ◽  
Age Dating ◽  
Marie Curie ◽  
Ernest Rutherford ◽  
Relative Age ◽  
Geologic Time ◽  
The Earth ◽  
Geologic Time Scale ◽  
Geologic Maps ◽  
History Of

Geologists first unraveled the geologic time scale by relative age-dating, discussed in the last chapter. Once geologists sorted out the order of rock units, subsequent advances in methodologies, detailed in this chapter, by chronometric and numerical means based on radioisotopes, other atomic measures, and quantitative techniques, were employed to measure time. Many minerals and rocks have “clocks” within them that can be used to pin down the actual age of the particular geologic sample or the age of boundaries between formal units of the geologic time scale. This chapter explains how geologists decipher those clocks and determine the ages of rocks by numerical age-dating. The history of radioisotopes is tracked, starting with Ernest Rutherford and Pierre and Marie Curie. The modern geologic time scale is depicted and expanded upon, along with why it is essential for geologic maps and how the time scale can help with people-sized problems and challenges faced on the Earth.

Sign in / Sign up

Export Citation Format

Share Document