Paleomagnetic Study of the Portage Lake Volcanics exposed in the Quincy Mine


Autoria(s): Michels, Alexander Christopher
Data(s)

01/01/2013

Resumo

A detailed paleomagnetic and rock-magnetic investigation was conducted on thirty six basaltic flows of the ~1095 Ma Portage Lake Volcanics. The flows were sampled along the East Adit of the Quincy Mine (Hancock, MI). Thirty two flows yielded well-defined primary magnetization directions carried by magnetite. A secondary magnetization component carried by hematite was also found in twenty nine flows. After correction for serial correlation between the flows, nineteen independent mean directions were calculated. The corresponding paleomagnetic pole is located at 25.5 °N, 182.1 °W (A95 = 3.5°). The new pole overlaps with the pole from the ~1087 Ma Lake Shore Traps suggesting a standstill of the North American plate during that time period. The low angular dispersion of virtual geomagnetic poles (S = 7.9°) suggests that the flows were erupted within a short time period, or that the strength of geomagnetic secular variation was lower than that of the recent field.

Formato

application/pdf

Identificador

http://digitalcommons.mtu.edu/etd-restricted/136

http://digitalcommons.mtu.edu/cgi/viewcontent.cgi?article=1135&context=etd-restricted

Publicador

Digital Commons @ Michigan Tech

Fonte

Dissertations, Master's Theses and Master's Reports - Restricted

Palavras-Chave #Basalt #Midcontinent Rift #paleomagnetism #Portage Lake Volcanics #Quincy Mine #rock magnetism #Geology #Geophysics and Seismology
Tipo

text