Methods of Sample Preparation and X-Ray Diffraction Data Analysis, X-Ray Mineralogy Laboratory, Deep Sea Drilling Project, University of California, Riverside

Cook, Harry E.; Johnson, Paul D.; Matti, Jonathan C.; Zemmels, I.

doi:10.2973/dsdp.proc.28.app4.1975

Cited by 146 publications

(127 citation statements)

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“…Ten powdered sediment samples from each site were mounted as unoriented powder by the backside method (Brindley and Brown 1980) and submitted to XRD between 2u and 45u 2h. The data were analyzed in a semi-quantitative way following Cook et al (1975). The intensity of the 3.39-Å , 3.03-Å , and 3.00-Å peaks were used to estimate the mineral fractions of aragonite, lowmagnesium (Mg) calcite (LMC), and high-magnesium calcite (HMC).…”

Section: Methodsmentioning

confidence: 99%

The influence of pore‐water advection, benthic photosynthesis, and respiration on calcium carbonate dynamics in reef sands

Rao

Polerecký

Ionescu

et al. 2012

Limnology & Oceanography

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To investigate diel calcium carbonate (CaCO 3 ) dynamics in permeable coral reef sands, we measured porewater profiles and fluxes of oxygen (O 2 ), nutrients, pH, calcium (Ca 2+ ), and alkalinity (TA) across the sedimentwater interface in sands of different permeability at Heron Reef, Australia. Background flushing rates were high, most likely as a result of infaunal burrow irrigation, but flux chamber stirring enhanced pore-water exchange. Light and pore-water advection fueled high rates of benthic primary production and calcification in sunlit surface sediments. In the light, benthic photosynthesis and calcification induced surface minima in Ca 2+ and TA and peaks in pH and O 2 . Oxygen penetration depth in coarse sands decreased from , 1.2 cm during the day to , 0.6 cm at night. Total oxygen uptake (TOU) in dark chambers was three to fourteen times greater than diffusive uptake and showed a direct effect of pore-water advection. Greater sediment oxygen consumption rates were observed in higher permeability sands. In the dark, TA release was not stimulated by increasing TOU because of a damping effect of pore-water advection on metabolic CaCO 3 dissolution efficiency. On a daily basis, CaCO 3 undergoes net dissolution in Heron Reef sands. However, pore-water advection can reverse the CaCO 3 budget and promote CaCO 3 preservation under the most energetic conditions.

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Section: Methodsmentioning

confidence: 99%

The influence of pore‐water advection, benthic photosynthesis, and respiration on calcium carbonate dynamics in reef sands

Rao

Polerecký

Ionescu

et al. 2012

Limnology & Oceanography

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“…The limitation on accuracy is mainly in the use of the weighting factors (derived by Cook, et al, 1975 Strictly speaking, the weighting factors are only valid when used with the X-ray diffraction system for which they were derived. However, due to the similarity of the instruments involved, it was thought that these factors should apply to this work.…”

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confidence: 99%

Studies of deep-sea sedimentary microtopography in the North Atlantic Ocean

Flood¹

1978

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partial fulfillment of the requirements for the degree of Doctor of Philosophy.. ABSTRACTMany of the small-scale topographic features (dimensions of centimeters to kilometers) found on the Blake-Bahama Outer Ridge (western North Atlantic, water depth greater than 4000 m) and in the Rockall Trough (northeastern North Atlantic, water depth greater than 2000 m) have been formed as bed forms of deep currents. These bed forms, all developed in cohesive sediments, include current ripples (spacings of tens of centimeters, formed transverse to the flow), longitudinal triangular ripples (spacings of meters, formed in sandy muds and parallel to the flow), furrows (spacings of tens to 100's of meters, formed parallel to the flow and presently either erosional or depositional), and regular sediment waves (spacings of a few kilometers, now found oblique to the flow and migrating either upstream or downstream).The local distribution of any given bed form is influenced by the presence of larger features. Bed forms are often found in zones which strike parallel to the regional contours.Debris flows, affecting areas of 1000's to 10,000's of square kilometers, are also present in these areas. A debris flow studied in the Rockall Trough is erosional at its shallowest depths and depositional at greater depths. Gravitational flows strike perpendicular to the contours. Pockmarks (tens of meters in diameter, marking fluid seeps) are also found on the Blake-Bahama Outer Ridge.The larger topographic features (greater than several meters) with steep slopes (greater than about 200) can be observed on surface echo-sounding profiles either as fields of regular hyperbolic echoes (e.g., echoes from regularly spaced furrows), fields of irregularly spaced, dissimilar hyperbolae (e.g., echoes from blocks, ridges, and folds in debris flows), or as regular features whose structfre is often obscured by side echoes (e.g., echoes fro .sediment waves).Although nearbottom investigations are required to describe the features, the nature of the sea floor can often be inferred from the character of the echo-sounding profile. Similar echo-sounding records in different areas of the ocean indicate the presence of similar sea-floor features.The morphology of the bed forms studied and the current and temperature structure of the overlying water column lead to conclusions about bed form origin and present-day interactions with deep currents.Furrows form as erosional bed forms during high-velocity (>20? cm/sec) current events by large, helical secondary circulations in the bottom boundary layer. Once formed, furrows may develop into depositional features, or they may continue as erosional ones, depending on the local currents and the sediment supply.Large, regular sediment waves may be formed at current speeds of 5 to 10 cm/sec by lee waves generated by topographic irregularities on the sea floor, such as submarine canyons, or by instabilities in the flow of deep, contour-following currents. Sediment waves develop where there is an abundant supply of sediment an...

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“…Pre-processing included sieving the previously dried samples using a 30 µm sieve, mixing the sample with 10 mL of ethanol, processing in the micronizer and centrifuge, and drying overnight at 60°C (Cook et al, 1975). After pre-processing, samples were analyzed on the XRD by the Reflective Transmission Spinner with the automatic divergence slit between 4° and 70° scans.…”

Section: Laboratory Methodsmentioning

confidence: 99%

Testing the effectiveness of beryllium-7 as a tracer of the movement of sediment over short periods along a cave stream in Hidden River Cave, Kentucky U.S.A.

Broderick¹,

Wicks²,

Paylor³

2017

JCKS

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testinG tHe effeCtiveness of BerylliuM-7 as a traCer of tHe MoveMent of sediMent over sHort Periods alonG a Cave streaM in Hidden river Cave, KentuCKy u.s.a. AbstractA feasibility study using beryllium-7 ( 7 Be) as a tracer of the movement of sediment through a karstic basin over short timescales of 2 to 3 months was undertaken. If 7 Be is an effective tracer of sediment movement, then the average 7 Be activity measured on sediment collected from backwater facies after high-flow events would be higher than that measured after periods of low-flow conditions. To test this, sediment was collected along a cave stream in Hidden River Cave, Kentucky, U.S.A. At the most basic level, collected sediment had measureable 7 Be activities, so using 7 Be to track movement of sediment from the surface into karstic basins is a viable method. In addition, the measured 7 Be activities were higher after a period of rainfall and presumably high flow events (> 1 d m) than after a period of relatively few rainfall events and presumably low-flow conditions (0.16 d m).Caroline A. Broderick, Carol M. Wicks, and Randall L. Paylor. Testing the effectiveness of beryllium-7 as a tracer of the movement of sediment over short periods along a cave stream in Hidden River Cave, Kentucky U.S

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Methods of Sample Preparation and X-Ray Diffraction Data Analysis, X-Ray Mineralogy Laboratory, Deep Sea Drilling Project, University of California, Riverside

Cited by 146 publications

References 1 publication

The influence of pore‐water advection, benthic photosynthesis, and respiration on calcium carbonate dynamics in reef sands

The influence of pore‐water advection, benthic photosynthesis, and respiration on calcium carbonate dynamics in reef sands

Studies of deep-sea sedimentary microtopography in the North Atlantic Ocean

Testing the effectiveness of beryllium-7 as a tracer of the movement of sediment over short periods along a cave stream in Hidden River Cave, Kentucky U.S.A.

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