Instrument data from three buoys in Lake Superior provide a reliable record of water temperatures since about 1980, and the information also shows that, with water temperatures running in the mid-to-upper 60s (and even warmer closer to shore), âwe are at record temperatures for this time of year,â according to Austin.
The talc is formed by the alteration of sedimentary magnesium carbonate rocks (dolomite and magnesite) at elevated temperature and pressure below the earth's surface. While the magnesium is fixed in situ, the silica is transported by silica-containing hot fluids to react with the Magnesium- bearing carbonates to form talc. These altered rocks are then talc-rich dolomites or magnesites. This type of deposits usually deliver the massive talcs accompanied by carbonates, chlorite and some quartz.
Last year, another Harvard team found talc - made from a mineral called hydrous magnesium silicate - raised the risk of ovarian cancer by 41% and urged women not to use it. No carbon emissions are released from the magnesium silicate raw material used, and overall more CO2 is absorbed than emitted during production.