Carbon in Earth’s fluid envelopes—the atmosphere and hydrosphere—plays a fundamental role in our planet’s climate system. It is also essential for the origin and evolution of life, for a large fraction of the energy we use, and for the multitude of carbon‐based materials so essential to the modern world. Yet the source and original quantity of carbon in our planet is uncertain (Marty et al., 2013), as are the identities and relative importance of early chemical processes associated with planetary differentiation (e.g., the moon‐forming impact, core formation, the onset of plate tectonics). Numerous lines of evidence point to the early and continuing exchange of substantial carbon between Earth’s surface and its interior (Dasgupta, 2013), such as information carried by subducted carbon trapped in diamonds, mantle‐derived magmas rich in carbon, carbonate‐bearing rocks found in fossil subduction zones, and springs carrying deeply sourced carbon‐bearing gases (Burton et al., 2013; Jones et al., 2013; Ni & Keppler, 2013; Shirey et al., 2013). Although quantifying the input and output fluxes is challenging, there is little doubt that a substantial amount of carbon resides in our planet’s interior (Dasgupta and Hirschmann, 2010, Kelemen & Manning, 2015). 

Carbonate ramps are carbonate platforms which have a very low gradient depositional slope (commonly less than 0.1 ~ from a shallow-water shoreline or lagoon to a basin floor (Burchette & Wright 1992). A large proportion of carbonate successions in the geological record were deposited in ramp-like settings. Nevertheless, ramps remain one of the more enigmatic carbonate platform types. In contrast to steepersloped

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.

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 <...>