AboutC. Robert Reszka, Jr. Expertise I can answer any general geology question (rocks, minerals, stratigraphy, geomorphology etc.). My expertise is in the geology of the Michigan Basin, PreCambrian, Paleozoic and Recent. I can answer questions concerning mining and petroleum exploration and production and the laws concerning those activities. I can also answer questions concerning stratigraphy of the Michigan Basin. I will also answer questions about mineral and rock collecting in the Basin. I won`t be able to answer many specific questions on hydrology, geophysics or geochemistry. I may be able to answer very general questions in those venues.
Experience I have been working for the State of Michigan for 24 years as a Geologist and a Resource Analyst. I have experience with Subsurface Geology and Petroleum Geology, mining in Michigan, and Sand Dune Mining and Protection issues.
Organizations Michigan Basin Geological Society
Publications Decade of North American Geology.
Bedrock Geology of Michigan
Question Would you please explain how bimodal vocalnics formed?
Answer Hi Ben,
Bimodal volcanic rocks are formed when both felsic and mafic material is emplaced from a single erupting vent. This usually happens where the crust is stretched and thinned due to an initial rifting event. The Basin and Range province of North America is a good example of such a location.
The process is not completely understood but what is thought to happen is that an upwelling plume of basaltic magma nears the surface and causes a melt of continental rocks to form. Most continental rocks are granitic. The basalt (mafic) and the granitic (felsic) melts form separate magma chambers. As the crust is thinned enough to fail, an eruption occurs that is fed by both chambers. So you get flows of felsic and mafic lavas.
