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.
How Deserts are Formed. Deserts are formed when rain clouds run into wind or mountains and drop rain in one area, leaving the land further away dry. Deserts that form near bodies of water are usually caused by winds. For example, the Sahara desert, near the Mediterranean. Deserts near mountains are formed when rain clouds drop their rain on one side, and the land on the other side of the mountains stays dry.