Geomagnetic stratigraphic dating
An age of 821 ± 13 ka obtained for a transitionally magnetized flow (LS118) provides the first volcanic evidence for a geomagnetic excursion occurring about 40 kyr prior to the transition.This interval has been successfully correlated with intensity minima present in high-resolution deep-sea records before the Matuyama–Brunhes transition.
The palaeosecular variation rates are very low (based on present data distribution) before 2000 BCE and then start to increase and fluctuate afterward, which is generally consistent with the pattern of palaeointensity variations in this area.Our approach is to use the high throughput of the u-channel SRM to: Materials for study come from a wide range of sources, including international science programs such as the Integrated Ocean Drilling Program and the International Continental Drilling Program, PI driven field programs and retrospective research on the large core collection available at the OSU-Marine Geology Repository. After an exciting week of getting settled into my apartment, I joined graduate students, REU students, our P. by Brendan Reilly | Jun 8, 2017 The OSU P-mag group is getting bigger!by Ben Freiberg | Aug 16, 2017 Brendan arrived around mid-afternoon in academic fashion, behind the wheel of a Subaru Forrester. We welcome Ben Freiberg, from Skidmore College, and Nick Lavoie, from North Carolina State University, who have made it just in time for Mo Walczak’s research cruise off the Oregon Margin next week. n/a Website10.1093/gji/ggw351 Mailing Address: GRDScripps Institution of Oceanography UC San Diego9500 Gilman Drive #0220La Jolla CA, 92093-0220Location: Ritter Hall 300ETel: 858-534-6084Fax: 858-534-0784Lab website: ltauxe at Earth’s magnetic field, one of the most enigmatic physical phenomena of the planet, is constantly changing on various time scales, from decades to millennia and longer.Ar ages were determined using individual hand-picked sanidine crystals from ash-flow specimens used in previous paleomagnetic studies at eight sites correlated by mineralogy, stratigraphic position, and magnetic inclination.A total of 20 new reliable archaeodirectional data from 12 independent sites are obtained after thermal demagnetization experiments.
These are the first set of archaeodirectional data in China produced since the 1990s.
Site-mean ages, which range from 18.43 Ma to 18.78 Ma with analytical precision (1 s.d.) typically 0.04 Ma, were obtained from areas near Fort Rock, AZ; Mc Cullough Mts, NV; Cima Dome, Parker Dam, Danby, Ludlow, Kane Walsh, and Stoddard Wash, CA.
The regional mean age determination is 18.71 ± 0.13 Ma, after the data were selected for sanidine crystals that yielded greater than 90% radiogenic argon (N=40).
The several orders of magnitude increase in data acquisitions allows new archives to be explored and older ones to be more thoroughly examined.
Discrete samples can also be rapidly measured with this system. My name is Nick Lavoie, and I just started as a graduate student here in the P-Mag Lab at OSU.
The published data are largely from the past 2 kyr and data from older time periods are rare.