ТЬе intention of this book is to provide а detai!ed synthesis of the enormous body of research which has Ьееп published оп carbonate sediments and rocks. Such rocks аге worthy of attention for severa! reasons. ТЬеу аге vo!umetrically а most signifcant part of the geo!ogica! record and possess тисЬ of the fossil гес-ord of !ife оп this p!anet. Most importantly they contain at !east 40% of the wor!d's known hydroсагЬоп reserves. ТЬеу a!so р!ау host to base meta! deposits and groundwater resources, and аге raw materia!s for the construction and chemica! industries. No other rock type is as economically important.

Sedimentology and stratigraphy are neighbors yet distinctly separate entities within the earth sciences. Put in a nutshell, sedimentology searches for the common traits of sedimentary rocks regardless of age as it reconstructs environments and processes of deposition and erosion from the sediment record. Stratigraphy, by contrast, concentrates on changes with time, on measuring time and correlating coeval events. Sequence stratigraphy straddles the boundary between the two fields. It is a sedimentologic concept as it uses depositional anatomy to reconstruct environments and lateral facies change, and it is part of stratigraphy as it studies the vertical succession of sedimentary rocks and their succession and correlation. <...>

A very large part of our understanding of carbonate sediments and rocks is derived from studies made with the microscope. Field work lays bare the gross relationships, but is apt to be hampered by the failure of many limestones to reveal themselves clearly in the hand specimen-a serious handicap in so complex a group of rocks. Geochemical and X-ray studies, though profoundly influential, suffer not only from the length of time between question and answer, but, above all, from their inability to take cognizance of the complex fabrics which are of such critical importance in this group of multicomponent rocks. The immediacy of the microscopical approach has sustained this method as the major research tool throughout the rapid expansion of carbonate studies since World War 11: the newer and more discerning classifications depend on it. The development of refined staining techniques, of replication, including the shadowing of acetate peels, combined with the use of the transmission and scanningelectron microscopes, have shown, along with the subtle methods of cathodoluminescence, that the microscope has a rich future <...>

The rare earth elements (REEs) are not as rare in nature as their name implies, but economic deposits with these elements are not common and few deposits have been large producers. In the past 25 years, demand for REEs has increased dramatically because of their wide and diverse use in hightechnology applications. Yet, presently the global production and supply of REEs come from only a few sources. China produces more than 95 percent of the world’s supply of REEs.