Filters: Tags: organic matter (X)
61 results (31ms)|
Filters
Date Range
Extensions Types Contacts
Categories Tag Types
|
The nanoscale molecular composition of kerogen is a challenging parameter to characterize given the chemical and structural complexity exhibited by this important biopolymer. However, kerogen composition will strongly impact its reactivity and so is a critical parameter to understand petroleum generation processes during kerogen catagenesis. The recent advent of tip-enhanced analytical methods, such as atomic force microscopy-based infrared spectroscopy (AFM-IR), has allowed for the major compositional features of kerogen to be elucidated at spatial resolutions at or below 50 nm. Here we apply AFM-IR to examine inertinite, an important kerogen maceral type, from an immature Eagle Ford Shale sample. Our data show...
Categories: Data;
Tags: Atomic force microscopy-based infrared spectroscopy (AFM-IR),
Energy Resources,
Geochemistry,
Organic matter,
Shale,
Solid bitumen is a petrographically-defined secondary organic matter residue produced during petroleum generation and subsequent oil transformation. The presence of solid bitumen impacts many shale reservoir properties including porosity, permeability, and hydrocarbon generation and storage, amongst others. Furthermore, solid bitumen reflectance is an important parameter for assessing the thermal maturity of formations with little to no vitrinite. While the molecular composition of solid bitumen will strongly impact associated parameters such as the development of organic matter porosity, hydrocarbon generation, and optical reflectance, assessing the molecular composition of solid bitumen in situ within shale reservoirs...
Categories: Data;
Tags: Energy Resources,
Geochemistry,
Oil and gas resources,
Organic matter,
Shale,
Optical sensors measuring fluorescence of non-biological sources (e.g., dissolved organic matter, wastewater, hydrocarbons, fluorescent dyes, etc.; hereafter referred to as fDOM) are increasingly used in water quality studies because they provide proxy measurements for a variety of contaminants and constituents of concern including metals, wastewater effluent, and DOM (measured in the lab as dissolved organic carbon, (DOC)) concentrations. Similarly, sensors measuring biological (algal) fluorescence (hereafter referred to as chlorophyll (fChl) and phycocyanin (fPC), have gained popularity to measure phytoplankton concentration, biomass, and even primary productivity. As additional sensors are coupled with ongoing...
Categories: Data,
Data Release - Revised;
Tags: California,
California Water Science Center,
EXO YSI,
Organic Matter Research Laboratory,
Sacramento,
Note: this data release has been superseded by version 2.0, available here: https://doi.org/10.5066/P91LJNAU Optical sensors measuring fluorescent dissolved organic matter (fDOM) are increasingly being used in water quality studies because they provide proxy measurements for dissolved organic matter concentrations (DOC). Similarly, chlorophyll-a (chl-a) fluorescence sensors have gained popularity as a means to measure phytoplankton concentration, biomass, and even primary productivity using various approaches. As additional sensors are grouped for in situ monitoring, field calibration checks are becoming quite time consuming for even the basic set of sensors (i.e. pH, specific conductivity, turbidity) that require...
Categories: Data;
Tags: California,
California Water Science Center,
EXO YSI,
Organic Matter Research Laboratory,
Sacramento,
The tundra biome is the dominant terrestrial ecosystem of the circumpolar north, and its fate in a rapidly changing climate is of high scientific and socioeconomic concern. One of those concerns is that the majority of caribou herds throughout the circumpolar north are declining, perhaps as a result of climate change. The principal objective of this research is to reveal the connections between soil nutrient cycling, forage quality and caribou habitat selection. This framework is underpinned by the concept that tundra ecosystem productivity is ultimately driven by the thermodynamics of the system induced by climate. In winter, soil microbial processes drive N mineralization and thus N available for plant growth...
Categories: Data,
Project;
Tags: ALPINE/TUNDRA,
ALPINE/TUNDRA,
CARBON,
CARBON,
Conservation Planning,
Derived from 1:250,000-scale USGS HUC 8 boundaries, this dataset represents Mannings "n" surface roughness coefficient for the western USA. A weighted average was created for each HUC 8 watershed using approximate EMAP physical habitat substrate criteria.
The amount of carbon plants allocate to mycorrhizal symbionts exceeds that emitted by human activity annually. Senescent ectomycorrhizal roots represent a large input of carbon into soils, but their fate remains unknown. Here, we present the surprising result that, despite much higher nitrogen concentrations, roots colonized by ectomycorrhizal (EM) fungi lost only one-third as much carbon as non-mycorrhizal roots after 2 years of decomposition in a piñon pine (Pinus edulis) woodland. Experimentally excluding live mycorrhizal hyphae from litter, we found that live mycorrhizal hyphae may alter nitrogen dynamics, but the afterlife (litter-mediated) effects of EM fungi outweigh the influences of live fungi on root...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: 15N,
Decomposition,
Ecology Letters,
Pinus edulis,
ectomycorrhizal roots,
Derived from 1:250,000-scale USGS HUC 8 boundaries, this dataset represents the soil sodium absorption ratio for the western USA. A weighted average was created for each HUC 8 watershed using approximate EMAP physical habitat substrate criteria. The values are expressed as percent by weight of the <2 mm fraction.
Decomposition of plant matter is one of the key processes affecting carbon cycling and storage in tidal wetlands. In this study, we evaluated the effects of factors related to climate change (temperature, inundation) and vegetation composition on rates of litter decay in seven tidal marsh sites along the Pacific coast. In 2014 we conducted manipulative experiments to test inundation effects on litter decay at Siletz Bay, OR and Petaluma marsh, CA. In 2015 we studied decay of litter in high and low elevation marshes at seven Pacific coast sites. These data support the following publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R., Thorne, K.M., Dugger, B.D. and Takekawa, J.Y., 2017. Inundation, vegetation,...
Categories: Data;
Types: Citation;
Tags: Deschampsia cespitosa,
Distichlis spicata,
Pacific coast,
Salicornia pacifica,
USGS Science Data Catalog (SDC),
These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the geomorphic floodplain as derived from light detection and ranging (LiDAR) data and aerial photographic imagery. The floodplain represents...
These data were compiled to demonstrate new predictive mapping approaches and provide comprehensive gridded 30-meter resolution soil property maps for the Colorado River Basin above Hoover Dam. Random forest models related environmental raster layers representing soil forming factors with field samples to render predictive maps that interpolate between sample locations. Maps represented soil pH, texture fractions (sand, silt clay, fine sand, very fine sand), rock, electrical conductivity (ec), gypsum, CaCO3, sodium adsorption ratio (sar), available water capacity (awc), bulk density (dbovendry), erodibility (kwfact), and organic matter (om) at 7 depths (0, 5, 15, 30, 60, 100, and 200 cm) as well as depth to restrictive...
To assess the effect of organic matter on the transport of Cryptosporidium parvum oocysts in a geochemically heterogeneous saturated porous medium, we measured the breakthrough and collision efficiencies of oocysts as a function of dissolved organic matter concentration in a flow-through column containing ferric oxyhydroxide-coated sand. We characterized the surface properties of the oocysts and ferric oxyhydroxide-coated sand using microelectrophoresis and streaming potential, respectively, and the amount of organic matter adsorbed on the ferric oxyhydroxide-coated sand as a function of the concentration of dissolved organic matter (a fulvic acid isolated from Florida Everglades water). The dissolved organic matter...
Categories: Publication;
Types: Citation;
Tags: Cryptosporidium parvum,
Ferric oxyhydroxide,
Oocyst,
Organic matter,
Transport,
Derived from 1:250,000-scale USGS HUC 8 boundaries, this dataset represents the soil organic matter content for the western USA. A weighted average was created for each HUC 8 watershed using approximate EMAP physical habitat substrate criteria. The values are expressed as percent by weight of the <2 mm fraction.
These data were compiled to demonstrate new predictive mapping approaches and provide comprehensive gridded 30-meter resolution soil property maps for the Colorado River Basin above Hoover Dam. Random forest models related environmental raster layers representing soil forming factors with field samples to render predictive maps that interpolate between sample locations. Maps represented soil pH, texture fractions (sand, silt clay, fine sand, very fine sand), rock, electrical conductivity (ec), gypsum, CaCO3, sodium adsorption ratio (sar), available water capacity (awc), bulk density (dbovendry), erodibility (kwfact), and organic matter (om) at 7 depths (0, 5, 15, 30, 60, 100, and 200 cm) as well as depth to restrictive...
Here the spatial variation in Raman estimates of thermal maturity within individual organic domains from several shale geologic reference materials originating from the Boquillas, Marcellus, Niobrara, and Woodford Formations are assessed from the respective Raman response. We show that for all four shales the thermal maturity parameters extracted from Raman spectra by iterative peak fitting can vary widely across distances of ≤5 µm within the same organic domain.
Categories: Data;
Tags: CEMEX quarry,
Carter County, Oklahoma,
Del Rio, Val Verde County, Texas,
Energy Resources,
Geochemistry,
Here we report ultra-high resolution infrared mapping of organic matter functional group distribution in Tasmanites (algal microfossils) from the Upper Devonian Ohio Shale using optical photothermal infrared spectroscopy (O-PTIR). O-PTIR is capable of rapidly measuring the vibrational response of samples in situ with ~500-nm spatial resolution, well below the infrared diffraction limit. Our results indicate that organic matter within the fold apices regions (zones of greatest deformation) of relatively large Tasmanites is more aliphatic and less oxygen-rich than organic matter in the surrounding Tasmanites body. This contrasts with data from relatively thinner Tasmanites which show statistically invariant chemical...
These data were compiled to demonstrate new predictive mapping approaches and provide comprehensive gridded 30-meter resolution soil property maps for the Colorado River Basin above Hoover Dam. Random forest models related environmental raster layers representing soil forming factors with field samples to render predictive maps that interpolate between sample locations. Maps represented soil pH, texture fractions (sand, silt clay, fine sand, very fine sand), rock, electrical conductivity (ec), gypsum, CaCO3, sodium adsorption ratio (sar), available water capacity (awc), bulk density (dbovendry), erodibility (kwfact), and organic matter (om) at 7 depths (0, 5, 15, 30, 60, 100, and 200 cm) as well as depth to restrictive...
Derived from 1:250,000-scale USGS HUC 8 boundaries, this dataset represents the distance proximity to stream riparian zones for the western USA. A weighted average was created for each HUC 8 watershed using approximate EMAP physical habitat substrate criteria. The values are expressed in meters. Zero or null values represent sites where no stream was identified.
The role of saline lake sediments in preserving organic matter has long been recognized. In order to further understand the preservation mechanisms, the role of clay minerals was studied. Three sediment cores, 25, 57, and 500 cm long, were collected from Qinghai Lake, NW China, and dissected into multiple subsamples. Multiple techniques were employed, including density fractionation, X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM), total organic carbon (TOC) and carbon compound analyses, and surface area determination. The sediments were oxic near the water-sediment interface, but became anoxic at depth. The clay mineral content was as much as 36.8%, consisting mostly of illite, chlorite,...
Categories: Publication;
Types: Citation;
Tags: Carbon Compounds,
Clay Minerals,
Organic matter,
Pres
These data were compiled to demonstrate new predictive mapping approaches and provide comprehensive gridded 30 meter resolution soil property maps for the Colorado River Basin above Hoover Dam. Random forest models related environmental raster layers representing soil forming factors with field samples to render predictive maps that interpolate between sample locations. Maps represented soil pH, texture fractions (sand, silt clay, fine sand, very fine sand), rock, electrical conductivity (ec), gypsum, CaCO3, sodium adsorption ratio (sar), available water capacity (awc), bulk density (dbovendry), erodibility (kwfact), and organic matter (om) at 7 depths (0, 5, 15, 30, 60, 100, and 200 cm) as well as depth to restrictive...
|
|
