Geologic History

Overview of Geologic History

1. Pertinent Readings

Spaulding & Namowitz, Heath Earth Science, ch.

2. Pertinent E2C Workshops and Resources

Few LDEO scientists conduct research into what most people usually think of as “geologic history” as it is usually included in Earth Science courses; that is, fossils of reptiles, mammals, and other large organisms, evolution through the eras of the geologic time scale, and other familiar topics. However, LDEO is part of the Columbia Earth Institute, and many Columbia scientists are affiliated with such investigations through the American Museum of Natural History. LDEO scientists have been among those who utilized variations in paleomagnetism to develop our understanding of the age of the oceans. Micropaleontology—the study of the tiny fossils of diatoms, foraminifera and other planktonic organisms—have been key areas of research at LDEO. Much has been learned by studying microorganisms extracted from cores housed in the LDEO Deep-Sea Sample Repository. In addition, the Lamont campus is home to the East Coast Repository of the Ocean Drilling Project (now the Integrated Ocean Drilling Program, www.iodp.org).

Deep-Sea Core Repository

Apr. 2001—Scientist: Rusty Lotti

LDEO Deep-Sea Sample Repository

Feb. 2002—Scientist: Rusty Lotti

Visit To The Deep Sea Sample Repository

Feb. 2003—Scientist: Rusty Lotti

3. Key General Concepts

Relative and absolute time

Stratigraphic Principals—superposition, original horizontality, intrusions and extrusions, cross-cutting relationships

Index Fossils

Radioisotopes and half-life

Paleomagnetism

Geologic Time Scale

4. Questions about the Key Concepts (These are to be answered and submitted.)

1. Compare and contrast information available through relative versus absolute dating techniques.

2. Explain how to distinguish intrusions from extrusions, and what each indicates about the comparative age of the igneous and sedimentary rock layers.

3. What are the two most important characteristics of index fossils?

4. Explain how to use the index fossils represented in the ESRT.

5. Describe how to determine the age of a sample knowing the percent of “parent” (original) and “daughter” (decay product) isotopes remaining.

6. Why has paleomagnetism been so useful in determining the age of the sea floors?

7. Using adding machine tape, construct a time line model of the geological time scale.

8. Compare the methods used in piston coring with deep-sea drilling.

9. Briefly list at least three important discoveries made using microfossils recovered from deep sea cores.

10. Briefly list at least three important discoveries made using cores recovered by the JOIDES Resolution.

5. Educational Technology

Fossils have been among the major attractions for museum visitors for more than a century. Beginning as “curio cabinets,” museum displays have expanded exponentially. Since it is often difficult to bring student groups to museums, consider how to bring “virtual museums” to your classroom. Explore what is available pertinent to geologic time at the following museums:

American Museum of Natural History, New York www.amnh.org

Natural History Museum, Smithsonian Institution, Washington, D.C.

Royal Tyrrell Museum, Drmheller, Calgary, Canada

6. DLESE review

Open www.dlese.org. Follow the appropriate prompts to locate at least two web sites dealing with imaging. Send the URLs as part of your course submission materials. If possible, provide feedback to DLESE using the Community Review System.

7. Planning for Your Course

2. Identify representative state science education standards pertinent to this session’s theme.

3. Describe one activity in which students might utilize information or data available through the resources you used for this session.

Optional Opportunity

Through the efforts of Julie Ann and Brian Hugick, teachers in New York State have been able to receive samples of Eurypterids, the state fossils, by arrangement with Lang’s Fossils of Ilion. Glenn Dolphin, STANYS Director-at-Large for Earth Science, and Susan Sharp, Earth Science Subject Area Representative for the STANYS Central Section, are able to make arrangements for collecting visits by teachers to Lang’s Fossils.

There are also many other opportunities to participate in field experiences and discover more about the geologic history of our area. Each September, the New York State Geological Association offer guided field trips (www.nysgaonline.org.) Each spring, the Eastern Section of the National Association of Geoscience Teachers conducts its spring meeting and includes a variety of trips during the Saturday program (www.nagt.org.)

If possible, try to join your colleagues for these.