Identification info

Metadata Language

English (en)

Dataset Reference Date ()

2023-04-06

Identifier

http://data.bgs.ac.uk/id/dataHolding/13608066

Maintenance and update frequency

asNeeded

GEMET - INSPIRE themes

• Geology

BGS Thesaurus of Geosciences

• X ray spectroscopy
• Imagery
• Drill core

Keywords

• NERC_DDC

Limitations on Public Access

otherRestrictions

Other constraints

licenceOGL

Other constraints

Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Use constraints

otherRestrictions

Other constraints

The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints

Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Spatial representation type

vector

Topic category

• Geoscientific information

Extent

Cheshire County [id=12343]

Dataset Reference Date ()

2009

N

S

E

W

Begin date

2022-02-08

End date

2023-03

Code

OSGB 1936 / British National Grid (EPSG::27700)

Distribution Information

Data format

• JPG ()

• xml ()

• csv ()

• doc ()

• text files ()

Quality Scope

dataset

Other

dataset

Statement

The core was stored inside sealed PVC core liner prior optical imaging and XRF point measurements. The core was slabbed 1/3 to 2/3 down its length using a specially designed core clamp to allow for asymmetric core slabbing (Monaghan et al., 2021). High-resolution optical images of the slabbed and wet core sections within the core clamps were collected shortly after slabbing the core using a Geoscan V colour line-scan camera set to 10 ms exposure and a visible resolution of 50 µm. To visually enhance core features and structures the images were scaled using GQuickView (Geotek Ltd) and compressed into jpgs. The processed outputs are available in two folders LS_Processed_Images the scaled images and LS_Processed_Images_Ruler the scaled images with a ruler showing drilling depths. The jpg images are named using the core box number. The top of the image is the top of the core box, the base of the image is the base of the core box. Each corebox ID relates to a depth range listed within TH0424_Corebox_Depths.csv. In addition, a colour chart image was taken under the same illumination condition every 5th core section, which can be used for colour calibration and colour reference. The colour chart images are named using drillers depth of the 5 core sections imaged. XRF point measurements on the slabbed and wet core sections within the core clamps shortly after slabbing the core were collected at 5 cm intervals and 10 s exposure using a Geotek XYZ Core Workstation. The XRF data was acquired with no filter at 10kV for low Z range elements and with a 25-micron silver filter at 40kV for high Z range elements. XRF elemental data is presented as raw counts (peak area). The raw count data provides an indication of variation in elemental abundances along the core, but is not a quantitative analysis. Ka-Area is the peak area for the K-alpha emission line for that particular element. Ka AreaSd is the relative error, which is a function of uncertainty in the Ka emission line intensity and uncertainty in the background intensity at the line position. This uncertainty/error is expressed as 2 standard deviation (sd). The peak areas were fitted using bAxil, a software for XRF spectrum analysis and one fitting template. In this software, the overall chi-square value (Chi-squared) indicates the goodness-of-fit of the mathematical model compared to the experimental data, with lower values indicating a better fit. Ka-Areas of <500 counts should be considered with caution as signals for very low counts are primarily dominated by noise. The dataset was then processed to remove data points over cracks, missing core intervals and heavily fractured sections of core where no reliable data could be collected. The final dataset has been aggregated into XYZ_Processed_Data.csv and is presented in drillers depth. The XRF spectral data can be requested from ukgeosenquiries@bgs.ac.uk. In addition, replicate scans as well as reference sample points have been performed to ensure consistent acquisition conditions and to identify any instrumental drift. Replicate scans can be used to identify poor core condition, and corresponding poor XRF data quality. This data is compiled in XYZ_Replicates.csv and indicated within XYZ_Processed_Data.csv ("Replicate Scan?" column). The impact of water on X-ray fluorescence (XRF) point measurements was investigated using the last 7 m of core recovered from UKGEOS TH0424 borehole (94 to 101 m bgl). This core was slabbed, scanned wet in the clamps and then allowed to dry fully in the clamps for 54 days prior to re-scanning. The dataset: XRF_wet_vs_dry.csv provides a comparison of the wet (i.e. freshly slabbed) vs dry core XRF analysis.

Metadata

File identifier

f8aa0830-c6f1-2c75-e053-0937940a85ea XML

Metadata Language

English (en)

Resource type

dataset

Metadata Date

2023-12-01

Metadata standard name

UK GEMINI

Metadata standard version

2.3