Melbourne property prices have passed Sydney as the nation's fastest growing, although they still lagged well behind in terms of absolute cost. Melbourne's year-on-year dwelling price growth of 11 per cent is the nation's fastest. Sydney's annual property price growth of 10.5 per cent is the slowest in 29 months. Less than half the properties auctioned in Sydney over the weekend sold.
How Is Chalk Formed. Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. It forms under relatively deep marine conditions from the gradual accumulation of minute calcite plates (coccoliths) shed from micro-organisms called coccolithophores. It is common to find flint and chert nodules embedded in chalk.
Why Rock Strata Form. Sedimentary rocks form as more-or-less horizontal layers because of the way in which sediment (sand, mud, rock debris, shell fragments and so one) is deposited. All sedimentary rocks form when moving water, wind or ice erodes, transports and deposits sediment.