Theories Regarding Plate Tectonics With Thesis
- Length: 9 pages
- Sources: 4
- Subject: Geography
- Type: Thesis
- Paper: #89461369
Excerpt from Thesis :
d.). A researcher may determine if a rock sample is sedimentary by examining whether it consists of grains. An igneous (from the Latin word for fire) rock, known as granite, consists of minerals like quartz, mica, and feldspar. "Igneous rocks come from melted rock material, or magma, that lies under Earth's surface" ("How can you tell," n.d.), forming when magma from inside the Earth travels toward the Earth's surface, or a volcano forced it in the form of lava and ash above the Earth's surface, where it cools and crystallizes into rock. Metamorphic rocks, rocks, which may be sedimentary and igneous rocks, changed by intense heat or pressure while they form, come from hot, pressured conditions inside the Earth's crust. At times, these rocks cool and crystallize, into bands of crystals. A researcher may determine if a rock sample is metamorphic by examining the crystals to see if they are arranged in bands ("How can you tell," n.d.).
Images Worth a World of Words
On Mars's surface, magnetic stripes replicate fields in the Earth's sea floors, which some scientes assert could indicate that ancient crustal movements occurred on the Red Planet. ("Plate Tectonics on Mars?" 1999).
The following figure depicts "a map of Martian magnetic fields in the southern highlands near the Terra Cimmeria and Terra Sirenum regions centered around 180 degrees longitude from the equator to the pole" ("Plate Tectonics on Mars?" 1999).
It is where magnetic stripes possibly resulting from crustal movement are most prominent. The bands are oriented approximately east - west and are about 100 miles wide and 600 miles long, although the longest band stretches more than 1200 miles. The false blue and red colors represent invisible magnetic fields in the Martian crust that point in opposite directions. The magnetic fields appear to be organized in bands, with adjacent bands pointing in opposite directions, giving these stripes a striking similarity to patterns seen in the Earth's crust at the mid-oceanic ridges.
Imagine a thin coat of dried paint on a balloon, where the paint is the crust of Mars," explained Dr. Mario Acuna of Goddard, principal investigator on the Global Surveyor magnetometer. "If we inflate the balloon further, cracks can develop in the paint, and the edges of the cracks will automatically have opposite polarities, because nature does not allow there to be a positive pole without a negative countepart." ("Plate Tectonics on Mars?" 1999)
Plate Tectonics on Mars?" 1999). PHOTO CREDIT: NASA, Jack Connerney, Mario Acuna, Carol Ladd
Plate Tectonics on Mars?" 1999)
Info in Red not yet rewritten Apr. 29, 1999: NASA's Mars Global Surveyor has discovered surprising new evidence of past movement of the Martian crust, suggesting that ancient Mars was a more dynamic, Earth-like planet than it is today.
Scientists using the spacecraft's magnetometer have found banded patterns of magnetic fields on the Martian surface. The adjacent magnetic bands point in opposite directions, giving these invisible stripes a striking similarity to patterns seen in the crust of Earth's sea floors.
An artist's concept comparing the present day magnetic fields on Earth and Mars. Earth's magnetic field is generated by an active dynamo - a hot core of molten metal. The magnetic field surrounds Earth and is considered global (image B, below). The various Martian magnetic fields (image a, above) do not encompass the entire planet and are local. The Martian dynamo is extinct, and its magnetic fields are "fossil" remnants of its ancient, global magnetic field. IMAGE CREDIT: NASA Mario Acuna, Jack Connerney, Chris Meaney
The bands of magnetized crust apparently formed in the distant past when Mars had an active dynamo, or hot core of molten metal, which generated a global magnetic field. Mars was geologically active, with molten rock rising from below cooling at the surface and forming new crust. As the new crust solidified, the magnetic field that permeated the rock was "frozen" in the crust. Periodically, conditions in the dynamo changed and the global magnetic field reversed direction. The oppositely directed magnetic field was then frozen into newer crust.
Plate Tectonics on Mars?" 1999)IMAGE CREDIT: NASA Jack Connerney/Mario Acuna/Chris Meaney
These images are an artist's concept of the process that may have generated magnetic stripes in the crust of ancient Mars. In the left image, the blue arrows and compass needle indicate the direction of the magnetic field. The yellow-orange shape represents a pool of molten rock (magma) upwelling beneath the Martian crust. The red and blue bands are magnetized crust on either side of a spreading center, or rift. ("Plate Tectonics on Mars?" 1999)
The sedimentary record of early planetary history which Mars possesses, according to www.highbeam.com/doc/1P3-1445150761.html"10 questions that are driving 21st-century earth science" (2008), reportedly predates the oldest rocks on Earth rocks, as well as those on other star systems with planets. In the spirit of scientists, currently turning toward Mars, in the search for a number of answers contributing to life, the researcher proposes to utilize *** two geophysical methods to test the *** theory of Mars tectonics. To complete this project the researcher would initially land *** and collect data for 2-4 weeks [assuming geophysical principles on Mars replicate those on earth].
Long-term records, the researcher would prefer to begin to collect would include, but not be limited to:
Continents in Collision: Pangea Ultima. (2000, October 6). 5 Dec. 2008 http://science.nasa.gov/headlines/y2000/ast06oct_1.htm.
How can you tell rocks on another planet apart? (N.d.). Earth and Apace Sciences. University of Washington. http://depts.washington.edu/rocknout/Lesson%20Plans/Rocks_Mars_Rover.pdf.
Kerr, Richard a. "Signs of plate tectonics on an infant Mars" Science. Washington. Apr 30. 1999. Vol. 264. lss. 5416; pp. 719-721.
The Columbia Encyclopedia, Sixth Edition. 2008. HighBeam Research. 5 Dec. 2008 http://www.highbeam.com.
Mcrae, Kim a. "Martian stripes imply ancient plate tectonics." The Chronicle of Higher Education. Washington: May 7, 1999. Vol 4.5. Is.. 35; pg. A24.
A www.highbeam.com/doc/1P3-1510493381.html" Mission to Mars could bring back 'rocks and life' between 2018 and 2033." The Hindustan Times. HT Media Ltd. 2008. HighBeam Research. 5 Dec. 2008 http://www.highbeam.com.
A www.highbeam.com/doc/1P3-1511856571.html" NASA spacecraft shows diverse, wet environments on ancient Mars. U.S. Fed News Service, Including U.S. State News. HT Media Ltd. 2008. HighBeam Research. 5 Dec. 2008 http://www.highbeam.com.
A www.highbeam.com/doc/1O80-platetectonics.html" plate tectonics." A Dictionary of Astronomy. 1997. HighBeam Research. 5 Dec. 2008 http://www.highbeam.com.
Plate Tectonics on Mars? (1999, April 29). Space Science News Home
http://science.nasa.gov/newhome/headlines/ast29apr99_1.htm www.highbeam.com/doc/1O80-TharsisMontes.html" Tharsis Montes." A Dictionary of Astronomy. 1997. HighBeam Research. 5 Dec. 2008 http://www.highbeam.com.
A www.highbeam.com/doc/1P3-1445150761.html"10 questions that are driving 21st-century earth science identified." The Hindustan Times. HT Media Ltd. 2008. HighBeam Research. 5 Dec. 2008 http://www.highbeam.com.
Research, not all used/included in following:
The clay-like minerals, called phyllosilicates, preserve a record of the interaction…