4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4 From: William Rose <raman@xxxxxxx> 4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4 *Help from field volcanologists familiar with basalt flows needed!!* I found a lava flow feature that I havenâ??t seen before, and I hope that some field observations somewhere exist. I hope that you will look at this description and give feedback: *Have you seen something like this? Where? Have you a photo to share?* Rusty rings resembling liesegang <https://en.wikipedia.org/wiki/Liesegang_rings_(geology)> in lava flows along the Lake Superior shoreline. The basaltic lavas are within a formation called the Copper Harbor Conglomerate within a member called the Lake Shore traps. They are found along a 60 km stretch of shoreline, above a below the present lake level. They are rusty globular rings up to 1m in diameter. We have not done any microscopic or mineralogical examination at this point. Our first look at liesegang literature reveals visual similarity, but they are thought to occur in sediments and not lavas. several photographs are included see: http://www.geo.mtu.edu/~raman/HazComm other possibly relevant links http://www.geo.mtu.edu/KeweenawGeoheritage/BlackLavas/Hunters_Point.html http://www.geo.mtu.edu/KeweenawGeoheritage/BlackLavas/Welcome.html Bill Rose Research Professor Michigan Tech raman@xxxxxxx ============================================================== Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI). ASU - http://www.asu.edu/ PSU - http://pdx.edu/ GVP - http://www.volcano.si.edu/ IAVCEI - http://www.iavcei.org/ To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx. To contribute to the volcano list, send your message to: volcano@xxxxxxx. Please do not send attachments. ============================================================== ------------------------------
