Mineral Resources On-Line Spatial Data
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|Name||Mount Mineral Formation|
|Geologic age||Proterozoic Z|
|Original map label||Zmmu|
|Comments||Part of Bronson Hill Zone (Ordovician and Older Rocks) Single detrital zircon analyses from the muscovite-garnet bearing upper quartzite member of the Mount Mineral Formation yield ages of 459-439 Ma, indicating that the quartzite is younger than earliest Silurian and may correspond to the Clough Quartzite. Older grains include 1000 Ma, 900 Ma, and 600 Ma groups. Authors state that "drastic rethinking" is required if the rocks of the upper quartzite member of the Mount Mineral, which lie beneath 200 m of Ordovician plutonic rock, are actually Silurian, rather than Proterozoic. The middle mica schist and amphibolite member is shown as Ordovician(?) and the basal quartzite member as Proterozoic(?). The Mount Mineral overlies the Proterozoic Poplar Mountain Gneiss (Robinson and others, 1992) per MA016.|
|Primary rock type||peridotite|
|Secondary rock type||serpentinite|
|Other rock types|
Metamorphic > Metaigneous > SerpentiniteLenses of partially serpentinized harzburgite containing abundant veins of anthophyllite.
Igneous > Plutonic > Ultramafic > PeridotiteLenses of partially serpentinized harzburgite containing abundant veins of anthophyllite.
Unpublished Digital Geologic Map of Massachusetts received from Rudi Hon at Boston College in 1998.
Zen, E-An (ed.), Goldsmith, R. (comp.), Ratcliffe, N.M. (comp.), Robinson, P. (comp.), Stanley, R.S. (comp.), Hatch, N.L., Jr., Shride, A.F., Weed, E.G.A., Wones, D.R., 1983, Bedrock Geologic Map of Massachusetts: U.S. Geological Survey, Reston, VA, scale 1: 250,000.
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