f3c4b9f6-30f9-435c-a4ff-607a0f9ecffc English MD_CharacterSetCode_utf8 Individual item (e.g. a one-off academic paper or single website) British Geological Survey Contact for the metadata enquiries@bgs.ac.uk pointOfContact 2024-11-07 ISO19115 2003/Cor.1:2006 Compositional data and their analysis: an introduction 2006-01-01 creation 2006-01-01 publication revision MICA WP3 2017-09-25T10:33:00 Record extracted from Batch 2 spreadsheet MICA_B2-24 https://www.mica-project.eu/ No additional information provided about the dataset A chapter In the book 'Compositional Data Analysis in the Geosciences: for theory to practice'. Compositional data are those which contain only relative information. They are parts of some whole. In most cases they are recorded as closed data, i.e. data summing to a constant, such as 100% - whole-rock geochemical data being classic examples. Compositional data have important and particular properties that preclude the application of standard statistical techniques on such data in raw form. Standard techniques are designed to be used with data that are free to range from -oo to +oo. Compositional data are always positive and range only from 0 to 100, or any other constant, when given in closed form. If one component increases, others must, perforce, decrease, whether or not there is a genetic link between these components. This means that the results of standard statistical analysis of the relationships between raw components or parts in a compositional dataset are clouded by spurious effects. Although such analyses may give apparently interpretable results, they are, at best, approximations and need to be treated with considerable circumspection. The methods outlined in this volume are based on the premise that it is the relative variation of components which is of interest, rather than absolute variation. Log-ratios of components provide the natural means of studying compositional data. In this contribution the basic terms and operations are introduced using simple numerical examples to illustrate their computation and to familiarize the reader with their use Website: http://sp.lyellcollection.org/content/264/1/1.full.pdf Purpose for data generation is not known The Geological Society of London Contact for the resource described by the metadata London W1J 0BG UK http://sp.lyellcollection.org/content/264/1/1.full.pdf WWW:LINK-1.0-http--link http://sp.lyellcollection.org/content/264/1/1.full.pdf Link for further information on the resource Party that supplies the resource https://resources.bgs.ac.uk/images/minerals/micaGraphic/B2/MICA_B2-24.JPG MICA dataCentre Geological time MICA ontology (TemporalScheme) 2 General descriptive information / Report / Trade association (Report) MICA ontology (DataScheme) 2 Requirement for data generation: Voluntary Method of data or information generation: Academic research Exploration GEMET Concepts 2014-07-25 revision 2 Geochemical GEMET Concepts 2014-07-25 revision 2 Sciences dealing with the composition, structure, origin of the Earth's rocks GEMET Concepts 2014-07-25 revision 2 Detailed geochemistry MICA ontology (DomainScheme) 2 Regional geochemistry MICA ontology (DomainScheme) 2 Available for free for all purposes Not confidential English geoscientificInformation economy Geographical coverage not applicable Other group of countries (please provide more details) Individual item (e.g. a one-off academic paper or single website) Data uncertainty Are any uncertainty measures provided (e.g. standard errors, confidence intervals, etc.)? true Quality assurance procedures Are quality assurance procedures described? true Information generation methods Are data or information generation methods formally described? true Record review Reviewed by: British Geological Survey Record validation false Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 Organisation source implies that information should be of good quality Metadata is distributed with a CC BY-ND 4.0 (Attribution-NoDerivs 4.0 International) licence