Deep-sea pore fluids are potential archives of ancient seawater chemistry. However, the primary signal recorded in pore fluids is often overprinted by diagenetic processes. Recent studies have suggested that depth profiles of Mg concentration in deep-sea carbonate pore fluids are best explained by a rapid rise in seawater Mg over the last 10–20 Myr. To explore this possibility we measured the M...

Carbonate sediments may be cemented by a variety of forms of aragonite. calcite. or dolomite. The mineralogy of the cement has been regarded by most investigators as the product of the physico-chemical environment within the sediment at the time of cementation. This has been a reasonable working hypothesis until it was recently demonstrated that many different kinds of cement may occur in beach...

The modern Great Barrier Reef (GBR) is part of the world’s largest and best known mixed terrigenous-carbonate continental margin. The GBR shelf contains three shore-parallel sedimentary belts: an inner shelf zone of terrigenous sedimentation at depths of 0–22m; a middle shelf zone of sediment starvation at depths of 22–40m; and an outer shelf reef tract with its inner edge at ca. 40m depth. The...

A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present), present and future (2010-2100) time periods. Reef platform sediment production is estimated at 569 m3 yr-1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate rem...

Low-latitude continental shelves, mixed siliciclastic–carbonate sedimentary systems, provide an understanding of sedimentary environments driven by paleoclimatological processes. The Bonaparte Gulf, northwestern Australian continental shelf, is among the widest in the world, ranging to 500 km, with shallow carbonate terraces and platforms that were exposed during periods of lower sea level. The...

This study uses derivative spectroscopy to assess qualitative and quantitative information regarding seafloor types that can be extracted from hyperspectral remote sensing reflectance signals. Carbonate sediments with variable concentrations of microbial pigments were used as a model system. Reflectance signals measured directly over sediment bottoms were compared with remotely sensed data from...

The Atlantic Irish Regional Survey (AIRS96) sidescan sonar survey was carried out in August 1996. Covering an area of 200,000 km 2 it represented the largest reconnaissance seabed survey of the Irish Continental Shelf region. It covered both margins, together with much of the basin floor, of the Irish sector of the Rockall Trough and extended into the northern part of the Porcupine Seabight. Th...

Introduction While a picture may say a thousand words, scientists and engineers often need to extract precise, quantitative information regarding physical processes from photographic evidence. Image analysis can, for example, be used as part of a quality control process in an industrial application, to monitor earth systems from space using satellite data, or to reconstruct changes in past clim...