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Topic: Martian geologic timescale

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	Geologic timescale - Paleontology Wiki
		The geological time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth.
		The table of geologic periods presented here is in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy, and uses the standard color codes of the United States Geological Survey.
		Geologists and paleontologists constructed the geologic table based on the relative positions of different strata and fossils, and estimated the time scales based on studying rates of various kinds of weathering, erosion, sedimentation, and lithification.
	paleontology.wikia.com /wiki/Geologic_timescale (2019 words)

	Geologic time scale - Wikipedia, the free encyclopedia
		The geological time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth.
		The table of geologic periods presented here is in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy, and uses the standard color codes of the United States Geological Survey.
		Geologists and paleontologists constructed the geologic table based on the relative positions of different strata and fossils, and estimated the time scales based on studying rates of various kinds of weathering, erosion, sedimentation, and lithification.
	en.wikipedia.org /wiki/Geologic_timescale (2059 words)

	geologic timescale - HighBeam Encyclopedia
		geologic timescale a chronological scale of earth's history used to measure the relative or absolute age of any part of geologic time.
		Of the numerous timescales, the most common is based on geologic time units, which divide time into eras, periods, and epochs.
		Each geologic time chart varies, depending on the latest findings dating rocks and fossils of that particular age, or on the country where the chart originated.
	www.encyclopedia.com /doc/1E1-geolog-ts.html (449 words)

	CalendarHome.com - Geologic time scale - Calendar Encyclopedia (Site not responding. Last check: )
		The geologic time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth.
		The table of geologic periods presented here is in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy, and uses the standard color codes of the United States Geologic Survey.
		Because geologic units occurring at the same time but from different parts of the world can often look different and contain different fossils, there are many examples where the same period was historically given different names in different locales.
	encyclopedia.calendarhome.com /Geologic_timescale.htm (1813 words)

	Exobiology Strategy Report
		The martian atmosphere and volatile systems are key components to issues such as the possible origin of life at some time during Mars' history and the evolution of the martian climate.
		First, from the geological perspective, the issues around the early atmosphere involve (i) understanding what climatic conditions were required to produce the early extensive erosion of Mars surface and to allow the valley networks to form, and then (ii) what atmospheric composition can produce such conditions.
		Geological estimates of the total inventory of water are based on the amounts of water released from volcanic activity (both extrusive and intrusive) and from catastrophic flooding.
	cmex.ihmc.us /Exo_Strat/Docs/state.html (5688 words)

	Qwika - similar:Holocene
		The Martian geologic timescale (or perhaps more properly the areologic timescale) has three broad epochs defined by the number of impact craters on the surface; older surfaces have more craters.
		As with other older geologic periods, the rock beds that define the start and end are well identified, but the exact dates of the start and end of the period are uncertain.
		The Eocene epoch (56-34 Ma) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era.
	www.qwika.com /rels/Holocene (1695 words)

	[No title]
		The lack of magnetic field and geologic activity may both be a result of Mars's smaller size allowing its interior to cool more quickly than Earth's, though the details of such processes are still not precisely clear.
		However, none of these processes are likely to be significant over the typical lifespan of most animal species, or even on the timescale of human civilization and the slow loss of atmosphere could possibly be counteracted with ongoing low-level artificial maintenance activities.
		Martian Express, Ltd. has begun the process of Comet Mining with the goal of obtaining the raw materials required to produce the atmosphere we desire.
	www.martianexpress.net /Terraforming1.html (948 words)

	Terraforming K-12 Background Information for Lesson Plans & Science Fair Projects
		It is possible that over geological timescales - tens or hundreds of millions of years—Mars could lose its water and atmosphere again, possibly to the same processes that reduced it to its current state.
		On a longer timescale, and with the technology of the future (in perhaps 25-50 years), an artificial magnetosphere seems possible: If the energy of several large fusion-power-stations is used to power large superconducting magnets - the field should be strong enough to protect at least local settlements.
		It is thought that this may have contributed greatly to its current uninhabitable state, as the upper atmosphere is exposed to direct erosion by solar wind and has lost most of its original hydrogen to space.
	www.juliantrubin.com /encyclopedia/astronomy/terraforming.html (4662 words)

	MEPAG 8/14/00
		Timescales for this investigation are the last million years and the upper 1m to 1 km of geological materials.
		The propagation of high energy particles through the Martian atmosphere must be understood, and the measurement of secondary particles must be made at the surface to determine the buffering (or amplifying) effects of the Martian atmosphere, and the backscatter effects of the regolith.
		The propogationpropagation of high energy particles through the Martian atmosphereMartian atmosphere must be understood, and the measurement of secondary particles must be made at the surface to determine the buffering (or amplifying) effects of the Martian atmosphere, and the backscatter effects of the regolith.
	cmex.ihmc.us /CMEX/data/marsessy/MEPAG_MEP.html (4283 words)

	An Introduction To Exobiology
		Although the cold dry nature of the martian surface and the low atmospheric density had been determined from astronomical measurements even before the space age began, interest in the possibility of life on Mars remained high.
		The accepted explanation is that the martian soil contains a highly oxidizing component (perhaps hydrogen peroxide) created by a photochemical reaction between the soil, atmospheric water vapor and sunlight's ultraviolet radiation.
		Early martian lakes have another attractive characteristic: they could have provided habitable environments (that is, have been a source of liquid water) long after the rest of the surface of Mars had cooled to intolerable levels.
	www.lindbergh.k12.mo.us /mars/Sitecat/sitecat2/intrex.htm (2287 words)

	MIT EAPS: Facilities
		The Mineral Physics Lab is designed to study the phase diagrams and the physical properties of materials at in situ high pressure and high temperature.
		In addition, scanning cathodoluminescence images, which is an image formed by light emission in response to electron interaction with the sample, can also be obtained.
		Current topics include the evolution of the Martian dynamo and climate, the nature and origin of lunar magnetism, the earliest history of Earth's magnetic field, the fossil record of magnetotactic bacteria, Neoproterozoic and Cambrian global change, and the origin of magnetization in carbonate rocks.
	eapsweb.mit.edu /research/facilities.html (1314 words)

	Isochrons for Martian Crater Populations of Various Ages
		Broad Martian lava plains show mixes of lava flows with much greater variation in crater density and age than found in the lunar maria, not to mention that dunes and dust drifts cover some localized patches of these units.
		These results, taken together, suggest the important result that recent exhumation (and ice deposition) processes may operate on a timescale comparable to the last few high obliquity excursions (5 Ma, 20 Ma), and may be associated with subaerial deposition and later wind-removal of the ice-rich dust mantles proposed by Mustard et al.
		Martian Cratering 8: Isochron refinement and the chronology of Mars.
	www.psi.edu /projects/mgs/chron04c.html (2743 words)

	the 'bombardment' of meteors on one hemisphere of mars. - Bad Astronomy and Universe Today Forum (Site not responding. Last check: )
		Martian surface, like Earth, is submitted to weathering so crators would 'dissappear' over time, due to the natural environment like sand storms, wind etc.
		The bombardment was more or less evenly distributed, but only part of the martian surface was later reworked (mostly by volcanic activity) so the old craters were erased.
		Anyway, I just wanted to point out that escape velocity is about 5 km/s for Mars, meaning their energies are lowballed by about a factor of 3.5 at the very least (unless I missed something where they're proposing this asteroid material was in orbit around Mars before it randomly blew itself up :roll:).
	www.bautforum.com /showthread.php?t=10933 (2427 words)

	Clinton Goveas :: Wikipedia Reference (Site not responding. Last check: )
		The lunar geologic timescale is divided in time based on a few prominent impact events, such as Nectaris, Imbrium, Eratosthenes, and Copernicus.
		KREEP appears to be concentrated within the Procellarum KREEP Terrane, which is a small geologic province that encompasses most of Oceanus Procellarum and Mare Imbrium on the near side of the Moon.
		The lunar crust is composed primarily of the elements oxygen, silicon, magnesium, iron, calcium, and aluminium.
	www.clintongoveas.com /wikipedia/?title=Moon (6831 words)

	[No title]
		The prolonged geological evolution of Mars is recorded in the physical and chemical characteristics of its crust.
		Constraints on the composition and petrogenesis of the Martian crust.
		Geologic map of the MTM 40092, 40087, 35092, 35087, and 35082 quadrangles, Tempe-Mareotis region of Mars.
	www2.ess.ucla.edu /~nimmo/website/version3.doc (9526 words)

	geology. The Columbia Encyclopedia, Sixth Edition. 2001-05
		Historical geology includes paleontology, the systematic study of past life forms; stratigraphy, of layered rocks and their interrelationships; paleogeography, of the locations of ancient land masses and their boundaries; and geologic mapping, the superimposing of geologic information upon existing topographic maps.
		Each, except the Cenozoic, ended with profound changes in the disposition of the earth’s continents and mountains and was characterized by the emergence of new forms of life (see geologic timescale).
		On-site analyses of Martian soil samples and photographic mapping of its surface have given clues about its composition and geologic history, including the possibility that Mars once had enough water to form oceans.
	www.bartleby.com /65/ge/geology.html (772 words)

	Isochrons for Martian Crater Populations of Various Ages
		On the contrary, such a situation can give extremely valuable estimates of the timescale of the exhumation processes, not to mention the timescale of exposure of the original underlying surface (which in turn is a lower limit to its age).
		In general, however, in dating Martian units, we look for simpler situations where a relatively homogenous stratigraphic unit is identified, and which appears not to be contaminated by secondary-ejecta impact craters from any single, nearby, large fresh primary impact crater.
		Neukum and Ivanov (1994) challenged the Shoemaker-era conclusion and terminology, that the steep branch on the moon (or Mars) is associated with secondary ejecta from lunar (or Martian) primary craters.
	www.psi.edu /projects/mgs/chron04a.html (3665 words)

	Geotimes - July 2002 - Highlights - Planetary Geology
		Another study models the amount of liquid water that may be produced by melting of ground ice in the martian regolith when the planet is at high obliquity (105 year timescale), which results in increased surface temperatures and pressure.
		In addition to studies of martian hydrology, continuing analyses of MGS data improve models of martian gravity, magnetics, atmosphere and geologic history.
		Terrestrial analogs of martian surfaces were the topic of field trips in the Mojave desert in October of 2001, sponsored by NASA and the Lunar and Planetary Institute.
	www.agiweb.org /geotimes/july02/high_planet.html (1034 words)

	NASA MEPAG Report: Mars Science Goals, Objectives, Investigations, and Priorities: 2006 \| Mars Today - Your Daily ...
		A key to understanding the climatic and geologic record preserved in these deposits is to determine (i) the relative and absolute ages of the layers, (ii) their thickness, extent and continuity, (iii) their petrologic/geochemical characteristics (including both isotopic and chemical composition), and (iv) the environmental conditions and processes that were necessary to produce them.
		Unfortunately, the Martian atmosphere exhibits substantial variations in density at a given geometric height due to the influence of the diurnal cycle, seasonal cycle, large-scale atmospheric circulation, and the propagation of waves.
		Water is an important geologic material on Mars, influencing most geological processes including the formation of sedimentary, igneous and metamorphic rocks, the weathering of geological materials, and deformation of the lithosphere.
	www.marstoday.com /news/viewsr.rss.html?pid=19700 (12432 words)

	Areology - Wikipedia, the free encyclopedia
		The Martian geological timescale (or perhaps more properly the areologic timescale) has three broad epochs defined by the number of impact craters on the surface; older surfaces have more craters.
		With the end of volcanism and the absence of liquid water, the most notable geological process has been the oxidation of the iron-rich rocks by atmospheric peroxides, leading to the red iron oxides that give the planet its familiar color.
		There is some evidence that some portion of the Martian surface might be more silica-rich than typical basalt, perhaps similar to andesitic rocks on Earth, though these observations may also be explained by silica glass, phyllosilicates, or opal.
	en.wikipedia.org /wiki/Martian_geologic_timescale (1209 words)

	1998MarsPapers (Site not responding. Last check: )
		This is much as might be expected given that the decline in Martian geothermal heat flow should result in a progressive increase in the thickness of the cryosphere.
		Whilst the Clifford model is geologically reasonable, and can readily be described in a qualitative fashion, a quantitative approach inevitably requires estimates of its various physical parameters.
		The dichotomy between southern uplands and northern plains is shown along with the Argyre basin in the south, the Valles Marineris complex and the Chryse basin at the foot of the plains-uplands boundary.
	www.marssociety.org /content/proceedings1998/mar98060.htm (5665 words)

	Catalog Page for PIA01479
		The martian north and south polar regions are covered by large areas of layered deposits.
		Since their discovery in the early 1970's, these polar layered deposits have been cited as the best evidence that the martian climate experiences cyclic changes over time.
		It was proposed that detailed investigation of the polar layers (e.g., by landers and/or human beings) would reveal a climate record of Mars in much the same way that ice cores from Antarctica are used to study past climates on Earth.
	photojournal.jpl.nasa.gov /catalog/PIA01479 (831 words)

	Mars: A World Riven By H2O or CO2
		The fact that its most remarkable geological features, the "catastrophic outflows", seem to have erupted from areas much too small to contain them if the erupting material was liquid water.
		This includes many who still think that liquid water may also have played a significant part -- it may be, for instance, that the catastrophic outflows did mix a large outpouring of liquid water with their huge CO2 gas eruptions, turning Mars into a gigantic "soda fountain".
		This wouldn't quite rule out the possibility of Martian life -- it might conceivably have been able to evolve in those underground depths, or in small local areas where volcanic activity did allow near-surface liquid water to exist -- but it would obviously make it vastly more unlikely.
	www.spacedaily.com /news/lunarplanet-2001-01a4.html (1124 words)

	Geology 101, Timescale exercise
		To better understand the concept of geologic time, in this exercise you will produce a metaphorical time scale that relates important events in solar system history true to scale.
		Thus, in our example metaphorical time scale, if the full football field represents 5 billion years, the age of the chondrites lies only 10 meters from the oldest end, or 90 meters from the zero age end.
		The work you hand in should include your metaphorical timescale showing the location of all of the events listed above, as well as your determination of their age.
	geology.cwru.edu /~harvey/GEOL101/exercises/timescale.html (557 words)

	June GEOLOGY media highlights
		The researchers have determined that Martian rivers were about the same size as their counterparts on Earth, suggesting similar amounts of runoff from thunderstorms or rapid snowmelt.
		Even using a conservative method to estimate the amount of water discharged through the rivers, the Martian rivers matched their terrestrial counterparts in terms of the volume of water per second during these ancient episodes of flow.
		They describe how they made that map, and how it provided a geologic map of each fault surface, showing rock units on either side of the fault truncated by the fault, and how the two fault-surface maps were superimposed to create a rock-rock juxtaposition map.
	www.eurekalert.org /pub_releases/2005-06/gsoa-jgm060305.php (3624 words)

	Earth-Pages Archive News, Sensing
		Various papers reveal variations in the composition of pyroxenes in the predominantly mafic Martian surface rocks, those minerals, such as the sulphates gypsum and jarosite, which contain water and signs of weathering by water, and an awful lot about water and CO ices around the poles.
		Except perhaps for some of the current generation of geologists, who are immersed in their remote sensing training by false colour images of spectrally revealing multispectral image data, a great many professionals who engage in mapping cut their teeth on what is known simply as photogeology.
		There is an important caution: any dating on Mars depends on assuming a timescale based on counting impact craters and noting their relations to each other and different kinds of surface.
	www.earth-pages.com /archive/Remote.asp (5529 words)

	Creationist Geologic Time Scale
		Once this framework of Creationist geologic time was in place, many of their speculations could be added to other valid geologic observations which they generally ignore to produce Figure 1.
		They commonly argue that the geologic rock record and its fossil sequence is a vast conspiracy among pointy-headed academics who warp and misinterpret the evidence in an attempt to defend cherish beliefs about a science's particular version of the nature of the earth.
		Nowhere is mention given of the enormous halite deposits of the geologic record nor of their generally accepted origin by continuous evaporation of sea water flowing into semi-restricted basins.
	chem.tufts.edu /science/Geology/Wise/CreationistGeologyRefuted.htm (11926 words)

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