Figure 1. Grand Canyon nationwide playground preserves an iconic geologic surroundings and methods which range from 1,840 to 270 million years of age, including diverse paleontological sources;

Figure 1. Grand Canyon nationwide playground preserves an iconic geologic surroundings and methods which range from 1,840 to 270 million years of age, including diverse paleontological sources;

unconsolidated exterior build up; an intricate tectonic and erosion record; and Pliocene to Holocene volcanic build up. The Colorado River set up the training course through the canyon about six million years ago, and most likely developed from pre-existing drainages to its existing program. Geologic processes, including erosion of tributaries and slopes, and active tectonics still figure the canyon these days. The geologic record in Grand Canyon is a vital scientific chronicle and is also mostly responsible for their inspirational landscape.


Dominant for its geologic value, the fantastic Canyon the most learned geologic landscapes in this field. It includes a great record of three from the four eras of geological time, a rich and varied non-renewable record, a huge array of geologic functions and stone types, and numerous caverns containing extensive and considerable geological, paleontological, archeological and biological information. Truly regarded the best types of arid-land erosion on earth. The Canyon, incised by Colorado River, are immense, averaging 4,000 base deep because of its entire 277 kilometers. It’s 6,000 foot deep at the strongest aim and 15 miles at the widest. The image below shows the layers of rock that are revealed into the canyon.

Figure 2. drawing revealing the position, era and depth of the stone products uncovered for the large Canyon.

This is a geologic cross-section (maybe not interested in size) that presents the stratigraphy associated with the big Canyon. Put differently, it signifies just what rock levels would seem like should you decide got a knife and sliced lower through the Earth at certain place, like easy. You might be seeing those levels from the “side” associated with the easy within picture. Note that all three different rock (sedimentary, metamorphic, and igneous) are present in this cross section. Note the way the many years of the rock reduction in get older from the bottom to reach the top. Whether it weren’t already described, you think you will be able to spot the fantastic Unconformity near the bottom with the canyon?

How Old could be the big Canyon? (optional)

Hear experts mention age the great Canyon and also the debate throughout the relationships. Push the enjoy option in the remaining associated with the webpage to concentrate. (Transcripts available on the left menu as well.)

This associated informative document originates from the big Canyon manual papers, printed because of the big Canyon nationwide playground.


You will end up determining the relative order wherein geological occasions took place, as revealed inside general stratigraphic cross section (below). Stratigraphy will be the study on the stone strata, or levels, dating an artist and is usually used on sedimentary (and quite often volcanic) stones.

Figure 3. drawing showing cross-cutting interaction in geology. These interaction can help provide structures a relative years. Information: A – folded rock strata cut by a push error; B – large attack (slicing through A); C – erosional angular unconformity (cutting off A & B) upon which rock strata were placed; D – eruptive dyke (cutting right through A, B & C); Elizabeth – even more youthful rock strata (overlying C & D); F – regular failing (cutting right through A, B, C & E).

  1. Examine the 3-D cross section above. The cross section consists of proof folding in coating G (a squeezing associated with stone considering compression— we’ll find out more about that in module 11) and faulting among the list of numerous stone layers.
  2. Just what stone type(s) tend to be represented in each one of the layers B, grams, D, age (sedimentary, igneous, or metamorphic)? Describe the method that you determined this.
  3. Which kind of unconformity really does C represent? Explain. (sign: the options are disconformity, nonconformity, angular unconformity, or paraconformity.)
  4. That letter(s) or layer(s) of rock really does the Principle of Superposition utilize, and just why? Mention.
  5. Write the order for which each lettered occasion (A-H) took place the sequence, from oldest to youngest. (Hint: keep in mind that one and F were fault lines, D are a dike, and C try an unconformity.)
  6. At what part of the series do you believe the folding of unit G occurred, and just why? Clarify.
  7. In 3 – 4 sentences, describe the way the legislation of corner Cutting Relations relates to the cross section and the sequence where you purchased the occasions.
  8. Perform some searching on the web (or somewhere else) to find another simple geologic cross section that you choose.
    • Feature a graphic of your cross-section inside review, and explain the order in which activities took place the point.
    • Kindly set tags on your cross section in the event it does not already have them, so that it is clear which occasions you will be referring to.
    • Cite your origin for the cross-section, kindly!

Grading Rubric

10 details: All issues happened to be replied completely and precisely. Full sentences were utilized to answer the sample questions.

8 factors: All questions happened to be responded and had been primarily precise. Only 2 or 3 minor problems.

5 details: responses are as well quick and 1 – 2 inquiries are unanswered.

2 guidelines: Only really partial suggestions supplied.

0 points: would not complete the project.

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