Institute for Rock Magnetism

N.H. Winchell School of Earth Sciences

Twin Cities Campus, University of Minnesota



Geodynamo and Environmental Change:

Interpreting Paleorecords through Rock Magnetism

St John's College

Santa Fe, New Mexico

June 25-28, 1998

Conference Program

Sponsored by the National Science Foundation, USA

Scientific Themes

Critical Observations and Constraints for Comparing Paleomagnetic Field Records and Numerical Dynamo Models

Numerical modeling of the geodynamo is reaching a critical threshold, where meaningful comparisons can begin to be made between modeled behavior and reconstructed behavior of the real field. Model behavior may suggest previously-unrecognized phenomena (e.g., inner-core super-rotation), or provide insight into unresolved observational issues (e.g., asymmetric sawtooth paleointensity variation, or preferred VGP reversal paths). What are the questions that we should be asking of the numerical models, and what should we be looking for in paleofield records?

Dynamics of Environmental and Climate Change, and the Rock Magnetic Basis of Paleorecord Interpretation

Magnetic measurements of sediment cores or stratigraphic sections can provide rapid and nondestructive high-resolution information on possible paleoclimate and paleoenvironmental variation. However paleoclimatic interpretations of magnetic data remain model-dependent and nonunique, both in the inversion of magnetic measurements for quantification of mineralogy and grain size, and in linking variations in these sediment characteristics to specific climatic changes. Where do we go from here?

Problems and Opportunities in Analysis of Long-Core Magnetometer Data and Low-Temperature Magnetometry

These two types of data have attained a new prominence in the last few years, and the new capabilities they provide us for sample characterization are inevitably accompanied by new complexities in data processing, inversion, and interpretation. What is the state of the art, and where should we focus our efforts for further development?

Conference Schedule

Thursday    Friday    Saturday    Sunday

Thursday, June 25

3:00-5:30 pm: Registration and room check-in

5:30-7:00 pm: Dinner

7:00 pm: Welcome and Opening Comments

(Subir Banerjee, IRM, U. of Minnesota)

7:10 pm: Evening Session: Keynote lecture on geodynamo models:

When you've seen one reversal, have you seen them all?

(Gary Glatzmaier, Los Alamos National Laboratory)

8:10 pm: Discussion

9:00 pm: Close

Friday, June 26

7:30-9:00 am: breakfast

9:00 am: Morning Session: The dynamo and its paleomagnetic record

(Carlo Laj, chair/discussant)

9:05 am: Paleomagnetic data constraints: Dynamo modelers' best friend

(Catherine Johnson, DTM/IRIS)

9:20 am: Paleosecular variation records: A good product that needs to get better?

(Lavas: Laurie Brown, UMass-Amherst)

(Sediments: Steve Lund, USC)

9:50 am: Relative paleointensity timeseries: How large are the error bars?

(Jim Channell, U. of Florida)

10:05 am: coffee break

10:20 am: Response from the chair

(Carlo Laj, Laboratoire des Sciences du Climat et de l'Environnement (LSCE))

10:40 am: Open mike

12:00-1:30 pm: lunch

1:30 pm: Afternoon Session: Developments in basic rock magnetism: granulometry and composition

(Horst-Ulrich Worm, chair/discussant)

1:35 pm: Magnetic granulometry: 52 years of Kittel's domain theory, and 10 years of 3-d micromagnetics

(Wyn Williams, Edinburgh U.)

1:50 pm: Interpreting rock-magnetic measurements: can we isolate the information we want?

(Andrew J Newell, U. of Washington)

2:05 pm: Low-temperature magnetic measurements: How do they work? What do they mean?

(Subir K Banerjee, IRM, U. of Minnesota)

2:20 pm: break

2:35 pm: Response from the chair

(Horst-Ulrich Worm, Universität Göttingen)

2:55 pm: Open mike

5:00-6:30 pm: dinner

7:00 pm: Evening Session: Long term plans for NSF Earth Science

(Robin Reichlin, NSF/EAR Geophysics)

8:00 pm: Discussion

9:00 pm: Close

Saturday, June 27

7:30-9:00 am: breakfast

9:00 am: Morning Session I: Keynote lecture on environmental magnetism

Evolution from a curiosity to a true proxy parameter

(Frank Oldfield, PAGES)

9:30 am: Discussion

10:00 am: coffee break

10:15 am: Morning Session II: Magnetic and nonmagnetic proxy records of paleoenvironmental change

(Richard Reynolds, chair/discussant)

10:20 am: Validation of magnetic proxies of climate and environmental change with non-magnetic data

(Andrew Roberts, U. of Southampton)

10:35 am: Cyclostratigraphy and cyclic diagenesis in various sedimentary environments: A magnetochemical story

(Cor Langereis, 'Fort Hoofddijk', U. of Utrecht)

10:50 am: Discussion

12:00-1:30 pm: lunch

1:30 pm: Afternoon Session: Magnetic and nonmagnetic proxy records of paleoenvironmental change

(Richard Reynolds, chair/discussant)

1:35 pm: Environmental change, bacterial action, and magnetic "fallouts"

(Ken Nealson, NASA JPL)

1:50 pm: Sediment magnetic signatures of human activity: What is the physico/chemical basis?

(Ken Verosub, UC-Davis)

2:05 pm: Response from the chair

(Richard Reynolds, USGS)

2:20 pm: break

2:35 pm: Open mike

5:00-6:30 pm: dinner

evening: free

Sunday, June 28

7:30-9:00 am: continental breakfast

9:00 am: Morning Session I: Long-core magnetometry

(Ken Verosub, chair)


10:15 am: Morning Session II: Low-temperature magnetometry

(Subir Banerjee, chair)


noon: check-out and departure; brunch if desired