Geochemical data

• Published in: Using Geochemical Data pp. 1 - 18
• Main Author: Rollinson, Hugh R.
• Format: Book Chapter
• Language: English
• Published: United Kingdom Routledge 1993; Taylor & Francis Group
• Edition: 1
• Subjects: Geochemistry; IDMS; Melt Partition Coefficients; AFM Diagram; Electron Microprobe Analysis; INAA; Trace Element; AFM; X-ray Fluorescence Spectrometry; Stable Isotopes; Major Element Analysis; XRF Analysis; Geochemical Data; Neutron Activation Analysis; Oxygen Isotopes; High Field Strength Elements; Mass Spectrometry; AFC Process; ICP; RNAA; Radiogenic Isotopes; Continental Island Arc; Sulphur Isotope Fractionation; Sample Preparation; Trace Element Analysis
• ISBN: 9781138836990; 1138836990; 9780582067011; 0582067014
• DOI: 10.4324/9781315845548-1

This book is about geochemical data and how they can be used to obtain information about geological processes. Conventionally geochemical data are subdivided into four main categories: the major elements, trace elements, radiogenic isotopes and stable isotopes (see Table 1.1). These four types of geochemical data each form the subject of a chapter of this book. Each chapter shows how the particular form of geochemical data can be used and how it provides clues to the origin of the suite of rocks in question. Different methods of data presentation are discussed and their relative merits evaluated. Table 1.1 Whole-rock geochemistry of komatiite flows from the Belingwe greenstone belt, Zimbabwe (Data from Nisbet et al., 1987) ZV14 ZV85 ZV10 Major element oxides (wt%) SiO2 48.91 45.26 45.26 TiO2 0.45 0.33 0.29 Al2O3 9.24 6.74 6.07 Fe2O3 2.62 2.13 1.68 FeO 8.90 8.66 8.70 MnO 0.18 0.17 0.17 MgO 15.32 22.98 26.21 CaO 9.01 6.94 6.41 Na2O 1.15 0.88 0.78 K2O 0.08 0.05 0.04 P2O5 0.03 0.02 0.02 S 0.04 0.05 0.05 H2O+ 3.27 3.41 2.20 H2O− 0.72 0.57 0.28 CO2 0.46 0.84 1.04 Total 100.38 99.03 99.20 ZV14 ZV85 ZV10 Selected trace elements (ppm) Ni 470 1110 1460 Cr 2080 2770 2330 V 187 140 118 Y 10 6 6 Zr 21 16 14 Rb 3.38 1.24 1.38 Sr 53.3 32.6 31.2 Ba 32 12 10 Nd 2.62 1.84 2.31 Sm 0.96 0.68 0.85 Radiogenic isotope ratios εNd +2.4 +2.4 +2.5 87Sr/86Sr 0.7056 0.70511 0.70501 Stable isotope ratios (‰) δ18O +7.3 +7.0 +6.8 Note: Major elements and Ni, Cr, V, Y, Ba determined by XRF; FeO determined by wet chemistry; H2O and CO2 determined by gravimetry; Rb, Sr, Sm, Nd determined by IDMS.