The Meaning of Rocks

and gems, fossils, cliffs, canyons, mountains, etc.

Geology as a Historical Science

Daily Web Guide

| Syllabus | Schedule | Email Kerry Magruder |

Reading Assignment

Peters, No Stone Unturned . Preface and Chapter 3, "The Spectrum of the Sciences." (all)

Reminders

Remember to review class notes carefully to prepare for quizzes! Study before each class. Quizzes may also include questions about reading material assigned for that day and not yet covered in class. Be sure to do the reading assignments for the next class period. Daily web guides will provide study questions to guide you through new reading, in order better to prepare for quizzes and the final exam. For each quiz, expect one question about the previous lesson and one question about the assigned reading, with the former being at a higher level of difficulty. Clarification: Attendance at one of the weekly Friday night Planetarium presentations of the Mars Show will count as one journal. Complete the Mars focus and discussion questions worksheet and turn it in the week after viewing the show. Write the date you attended the Mars Show on your worksheet, and staple the worksheet to your ticket.   A $45 lab fee is required to cover costs of rock and mineral specimens and related supplies. After organizing them into a collection, these specimens will be yours to keep. This amount should be paid to Cindy Guinn, Division secretary. The first specimens will be handed out on February 25, but only to those who have paid for them.

Reading Focus Questions

Read the entire chapter, as well as the preface. Focus your attention on the following questions:

1. How might Peters respond if you asked her to define "the scientific method"? Would she say that there is such a thing?
2. What is the purpose of the discussion of figured stones? What is her point in bringing it up?
3. What does it mean to say that "almost all geologic problems are historical"?
4. How does the methodology of an historical science differ from other scientific methodologies? How is geology different from other sciences?
5. Answer questions 1 through 4 on page 39.
6. Answer questions 2, 3, and 4 on page 46.

Class Notes

Aesthetic meaning

• Are you wearing gems or ornamental rocks?
• Dante and crystals; Rime Petrose
• Romanticism, caves and fossils; Jules Verne, Journey to the Center of the Earth
• Thomas Burnet, Theory of the Earth, 1684
  • "In this smooth Earth were the first Scenes of the World, and the first Generations of Mankind; it had the beauty of Youth and blooming Nature, fresh and fruitful, and not a wrinkle, scar or fracture in all its body; no Rocks nor Mountains, no hollow Caves, nor gaping Chanels, but even and uniform all over. And the smoothness of the Earth made the face of Heaven so too; the Air was calm and serene; none of those tumultuary motions and conflicts of vapours, which the Mountains and the Winds cause in ours: 'Twas suited to a golden Age, and to the first innocency of Nature."

Moral meaning

• Staring at a rock is a ludicrous way to start a class!
• Lisbon earthquake
  • Voltaire, Candide
• Edward Hitchcock
  • The Religion of Geology, 1851
• John Muir, conservationism
• Mark Twain
  • "Man has been here 32,000 years. That it took a hundred million years to prepare the world for him is proof that that is what it was done for. I suppose it is, I dunno. If the Eiffel Tower were now representing the world's age, the skin of paint on the pinnacle-knob at its summit would represent man's share of that age; and anybody would perceive that that skin was what the tower was built for. I reckon they would, I dunno."
• James Hutton, Theory of the Earth, 1795
  • "A rock or stone is not a subject that, of itself, may interest a philosopher to study; but, when he comes to see the necessity of those hard bodies, in the constitution of this earth, or for the permanency of the land on which we dwell, and when he finds that there are means widely provided for the renovation of this necessary decaying part, as well as that of every other, he then, with pleasure, contemplates this manifestation of design, and thus connects the mineral system of this earth with that by which the heavenly bodies are made to move perpetually in their orbits...."

Economic meanings

• "How much is this worth?"
• William "Strata" Smith
• Amos Eaton, Erie Canal
• Desert Storm
• John Buchan, Prester John

Emblematic, mystical meanings

• Medieval lapidaries
  • Diamond fidelity test
• The Earth a microcosm
• Fossils sports of nature?

Social meanings

• Cabinets, museums
• Camaraderie among geologists
  • A masculine science?
• T.H. Huxley and disciplinary autonomy
• Robert Owen, "sorry swarm of lizards"

Chemical/mineralogical meaning

• Description and identification
• Minerals the alphabet of geology
• Rocks made of many different combinations of minerals

Historical meaning

• Johann Friedrich Blumenbach, 1790
  • "If one looks at fossils from the grand viewpoint that they are the most infallible documents in Nature's archives, demonstrating that our planet has gone through several upheavals, showing even the manner and to some extent the times of these major changes, thus making it possible to determine the relative ages of the various major formations&endash;it is obvious that their history must be regarded as one of the most important and instructive parts of all natural history, and especially of mineralogy."
• John McPhee, Basin and Range
  • "Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrain. In the rock itself are the essential clues to the scenes in which the rock began to form&endash;a lake in Wyoming, about as large as Huron; a shallow ocean reaching westward from Washington Crossing; big rivers that once rose in Nevada and fell through California to the sea...."
• Why are geologists storytellers?
  • Seek to reconstruct meaningful sequence of unique events
    • like a detective at the scene of a crime
    • Explanations consist of narratives of particular events rather than general laws
  • Fieldwork the most important source of evidence, not experiments or mathematical models
• T.H. Huxley on the Chalk
  • "A great chapter in the history of the world is written in the chalk. Few passages in the history of man can be supported by such an overwhelming mass of direct and indirect evidence as that which testifies to the truth of the fragment of the history of the globe, which I hope to enable you to read, with your own eyes, to-night.... During the chalk period, or 'Cretaceous epoch,' not one of the present great physical features of the globe was in existence. Our great mountain ranges, Pyrenees, Alps, Himalayas, Andes, have all been upheaved since the chalk was deposited, and the Cretaceous sea flowed over the sites of Sinai and Ararat. All this is certain, because rocks of Cretaceous or still later date, have shared in the elevatory movements which give rise to these mountain chains; and may be found perched up, in some cases, many thousand feet high upon their flanks."

Examples of historical detection

• Organic or chemical origin of...
  • chalk?
  • fossils?
  • Mud cracks, dendrites?
  • rose rocks?
  • stalactites?
  • Peters, figs. 3-1, 3-2, 3-3
  • "Difficult questions," Peters p. 39

Are fossils of organic or chemical origin?

• Location
  • Marine shells on mountain tops?
  • Creation, deluge, diminution of early sea, subterranean transport?
• Matter
  • How did soft shells/bones become hard rocks?
• Form and size
  • Why so different from living species?

Glossopetrae, tongue-stones

• Island of Malta
  • Paul, Acts
• Washed up on Mediterranean shore
• Niels Stenson, Steno
  • Comparative anatomist
  • Not chemical, but organic
  • Petrified teeth of sharks
• Relatively easy case
  • location near sea-level
  • matter not altogether different
  • form similar

Shark's head and teeth, glossopetrae
An often-reproduced illustration from Scilla, Steno, Leibniz, et al.
Now reproduced here courtesy History of Science Collections, University of Oklahoma