Lehigh's Paleomagnetism Laboratory has a 2G superconducting magnetometer with a built in af demagnetizer and an automatic sample delivery system. Our ASC thermal demagnetizer has been modified to allow a DC magnetic field to be turned on and off at preset temperatures during the cooling cycle. This will let us study remanence magnetic fabrics in red beds more efficiently. Our shielded room, built by Lodestar Magnetics (Gary Scott) is 3m by 5 m in size and has a nominal field of 1000 nT. Considering that the measurement space had a field of 90,000 nT before shielding, this is a huge improvement. We also have a GSD-5 Schonstedt af demagnetizer that has been modified to impart partial ARMs between alternating fields of 100 mT and 0 mT. This is used extensively for our remanence anisotropy studies of magnetite-bearing rocks. AMS can be measured with our KLY-3S Kappabridge. We routinely measure AMS for all the paleomagnetic samples we collect. We have a water tank consolidometer based on a design by Hamano (1980) that we have used over the years to study the effects of burial compaction on sedimentary rocks. Finally, we have two Pomeroy modified chain saws for collecting oriented rock cores samples.

Paleomagnetism students at Lehigh also have access to excellent electron optical facilities at Lehigh's Materials Science department. TEM, SEM, and microproble analyses are all possible. In the basement of Williams Hall (the EES building) is the Keck-funded lake core laboratory. It has a large cold room for storing lake cores and a Geotek multisensor track that can measure bulk susceptibility, P wave velocity, and gamma ray attenuation (porosity) downcore. The Keck lab is also equipped with a Mackereth piston corer which can be deployed on the lakes studied by EES faculty and students. The Mackereth corer takes 4" diameter cores up to 6 m long.

Paleomagnetism Laboratory Facilities:
2G 755 superconducting magnetometer with built in alternating field degausser and automatic sample delivery system
ASC TD-48 thermal demagnetizer
Lodestar Magnetics magnetically shielded room (nominal field 1000 nT)
KLY-3S Kappabridge for bulk susceptibility and anisotropy of magnetic susceptibility measurements
ASC impulse magnetizer
Schonstedt GSD-5 af demagnetizer modified for partial ARMs
Water tank consolidometer
2 Pomeroy sampling drills
 

Current Graduate Students
Dario Bilardello-Dario is working on red bed remanence and inclination shallowing in Maritime redbeds.

Dario at work in Newfoundland.

Michael Newton-Mike is measuring the rock magnetic properties of marls from the Pyrenees.

Mike sampling in New Brunswick, Canada

Recent NSF-funded Projects:
Developing an Inclination Correction for Red Bed Remanence and Its Application to Anomalously Shallow Inclinations in Tertiary Red Beds, Tarim Basin, China-This project demonstrated that the magnetic fabric of red beds can explain the anomalously shallow inclinations observed in Cretaceous and younger rocks from central Asia.  There is no need to appeal to standing non-dipole fields or cryptic shear zones.

Fold in the Neogene near Kuche, China      Mr. Sun, our expert driller, in redbeds near Kuche.   Field sampling area near Kuche.

Collaborative Research: Cretaceous Paleomagnetic Tests of the Baja British Columbia Hypothesis-This work showed that the 3000 km of paleolatitudinal offset originally attributed to the Nanaimo group is partially an artifact of compaction shallowing of inclination. Our data suggests that the offset is reduced by about one half.

                    Hornby Island-where we sampled the Nanaimo.         Taking a break to write up field notes on Hornby.

Collaborative Research: An Inclination Correction for the Valle Group Strata: Determining Cretaceous Paleolatitude of the Southern Peninsular Ranges Terrane-This work demonstrated that very shallow inclinations measured for the Valle Group are the result of secondary, post-tilting remagnetization in the Tertiary. However, anisotropy of remanence results indicate that primary magnetizations in the mid-Cretaceous Perforada Formation from the lowermost part of the Valle Grouphave been shallowed by compaction. After correction, there is no evidence for motion of the Peninsular Ranges terrane since the mid-Cretaceous.

Determining the cause of a magnetic mineral-paleorainfall correlation in recent lake sediments-Our work here focused on magnetotactic bacteria that dominate the magnetic signal of the recent sediments of Lake Ely in northeastern Pennsylvania. Our work showed that the variations in magnetic concentration (magnetosomes) correlates with historically recorded rainfall variations showing a link between magnetosome production and environmental factors.

Taking a freeze core through the ice and taking water samples through the ice on Lake Ely.

Current NSF-funded Projects:
The Red Bed Paleomagnetic Inclination Correction and the Accuracy of the Late Paleozoic North American Apparent Polar Wander Path-This work continues our study of red bed remanence anisotropy and inclination shallowing. We are applying an inclination shallowing correction to coeval red bed units in Maritime Canada to compare to our corrected results from the Mauch Chunk Formation from Pennsylvania. Preliminary results indicate a good correlation of corrected paleopoles, suggesting that red bed remanence needs to be checked for inclination shallowing, as well as magnetite-bearing rocks.



Sampling in Newfoundland.                        Sampling in New Brunswick.                     Heading for the sampling sites in Newfoundland.

Collaborative Research: High-Resolution Deformation Rates, Spain.  In this project we are using Milankovitch cycles recorded by magnetic mineral concentrations in Tertiary marls in the Pyrenees as a high resolution chronometer to time fold development. We have been quite successful using rock magnetism to provide a high resolution temporal framework of carbonate deposition in Mexican Cretaceous limestones.

Sampling the marls for rock magnetism.  Dave Anastasio using GPS for site location.      Preparing for a day's work.

Visit Ken Kodama's web page