Abstract Sand aprons are distinctive landforms that offer important insights into sedimentary dynamics for reef platform development. Here we link temporal and spatial scales of 21 sand in the southern Great Barrier Reef to understand their Holocene formation evolution response relative sea-level changes, depth Pleistocene base, contemporary morphodynamics. Our results show lagoon infilling is ...

In this paper, we present a new technique for collecting pore-water samples in coarseto fine-grained sandy sediments. We have used the technique both for in situ sampling and for pore-water extraction from sediment cores brought back to the laboratory, in both cases with a depth resolution as fine as 1 cm. The key device is a long, thin (;2 mm) stainless steel tube with a specially designed tip...

Stromatolites, laminated columnar and branched structures of limestone and dolomite, are the only macroscopic evidence of life for the first few billion years of earth history. These organo-sedimentary structures are a prominent constituent of Precambrian carbonate successions and occur sporadically throughout the Phanerozoic. They are hosts for metallic ores and serve as reservoir rocks for hy...

During ODP Leg 155, color reflectance was routinely measured downhole at all but one site to determine light-reflectance levels in the wavelength band of visible light (400 to 700 nm) of the sediments recovered. Reflectance measurements taken on previous ODP legs have demonstrated that lithologic changes in carbonate-rich (>20%) pelagic and hemipelagic sediments can be characterized using these...

Major processes of the nitrogen cycle (i.e., nitrogen fixation, denitrification, ammonia mineralization and nitrification) were investigated in coastal sediments of several Seychelles Islands. Sediments were represented by carbonate sands, except in Victoria Harbor where they were carbonate silt. Nitrogen fixation was measured by acetylene reduction assay, other processes were studied by an exp...

The carbon-cycle significance of soil carbonate fluxes is subject to large uncertainties because it is not clear precisely how much calcium is derived from atmospheric sources compared with that from the chemical weathering of silicate minerals. In the petrocalcic horizon (calcrete) of a Pleistocene soil from the USDA–SCS Desert Project area near Las Cruces, NM, approximately 1.5 g Ca=cm3 has b...

Sedimentary facies and foraminiferal assemblages of sediments sampled into seven Posidonia oceanica meadows from Western Mediterranean Sea were investigated. Six sampling sites are localised in Italy (Maratea, Ponza Island, Santa Marinella, Giglio Island, Osalla and Alghero), and one in France (Argentella, Crovani Bay, Corsica). The role of P. oceanica meadows in the sedimentary processes was i...

The redistributive transport of sedimentary, redox-sensitive metals such as iron (Fe) and manganese (Mn) along depth gradients in lakes or marine basins, particular the concentration these elements at local depressions, has been described “geochemical focusing.” However, impact variable redox conditions sediment–water interface on this process is not entirely understood. In study, we report tha...

Concentrated seabed deposits of polymetallic nodules, which are rich in economically valuable metals (e.g., copper, nickel, cobalt, manganese), occur over vast areas of the abyssal Pacific Ocean floor. Little is currently known about the diversity of microorganisms inhabiting abyssal habitats. In this study, sediment, nodule, and water column samples were collected from the Clarion-Clipperton Z...

fractionation studies on the sediment samples provide valuable information on the nature of the metals bound to the sediments. thirty three sediment samples of river adyar were collected during two seasons and speciation study was carried out. the industrial and domestic effluents are directed into the river course at many points in the middle and lower of the adyar river. to ascertain the exte...