Recent evidence indicates that large detrital aggregates, known as marine snow, are highly concentrated at pycnoclines and other density discontinuities in the water column due to turbulence, shear, and reduced sinking rates as settling aggregates encounter layers of higher density (MacIntyre et al, 1995). The characteristics of these thin layers of high aggregate abundance and their impacts on...

One of the central themes in modern ecology is the enduring debate on whether there is a relationship between the complexity of a biological community and its stability. In this paper, we focus on the role of detritus and spatial dispersion on the stability of ecosystems. Using Monte Carlo simulations we analyze two three-level models of food webs: a grazing one with the basal species (i.e., pr...

Muramic acid, a component of the muramyl peptide found only in the cell walls of bacteria and blue-green algae, furnishes a measure of detrital or sedimentary procaryotic biomass. A reproducible assay involving acid hydrolysis, preparative thin-layer chromatographic purification, and colorimetric analysis of lactate released from muramic acid by alkaline hydrolysis is described. Comparison of s...

Radionuclides, including (137)Cs, were released from the disabled Fukushima Daiichi Nuclear Power Plant and had been deposited broadly over forested areas of north-eastern Honshu Island, Japan. In the forest, (137)Cs was highly concentrated on leaf litters deposited in autumn 2010, before the accident. Monitoring of the distribution of (137)Cs among functional groups clearly showed the role of ...

New detrital-zircon geochronologic data reveal that a through-going paleoriver connected Texas with Nevada in Late Triassic time. Sandstone from the Upper Triassic Santa Rosa Sandstone (Dockum Group) from northwestern Texas contains a detrital zircon suite nearly identical to that found in western Nevada in the Upper Triassic Osobb Formation (Auld Lang Syne Group, correlative with the Chinle Fo...

Samples of Fish Canyon and Cobb Mountain sanidine monitor standards, irradiated and fused with 7 W of CO laser 2 power for ArrAr geochronology analyses, give Pb isotope composition and Pb concentrations that are indistinguishable from unprocessed aliquots of the same monitors. The absence of measurable change in Pb isotope composition indicates the feasibility of measuring the Pb isotope compos...

Deep-water depositional systems are the ultimate sink for vast quantities of terrigenous sediment, organic carbon and anthropogenic pollutants, forming valuable archives environmental change. Our understanding distribution these particles preservation signals, in deep-water is limited due to inaccessibility modern systems, incomplete nature ancient systems. Here, deposit a physically modelled t...

INTRODUCTION Forest soils are entities within themselves, selforganized and highly resilient over time. The transfer of energy bound in carbon (C) molecules drives the organization and functions of this biological system (Fisher and Binkley, 2000; Paul and Clark, 1996). Photosynthetic organisms reduce atmospheric C and store energy from solar radiation in the formation of complex C molecules. T...

U–Pb ages of individual detrital zircon grains from deltaic and turbidite sandstones of the lower to middle Pennsylvanian Haymond Formation (Marathon basin, west Texas) range from 320 Ma to 3 Ga, indicating a mixed provenance broadly similar to that of Ouachita Carboniferous turbidites and related fluvio-deltaic facies of Arkansas–Oklahoma. Differences with the Ouachita assemblage are attribute...