Advances in lithium isitope geochemistry / Достижения в литиевой изотопной геохимии

In this book we decided to attach the permil sign (‰) to all Li isotopic quantities. One way of viewing stable isotopes denoted by δ is that the arithmetic sets the results as being part-per-thousand quantities, so to place the ‰ on a value is redundant. However, this implies a certain familiarity from the reader. Our decision regarding the ‰ in this volume was guided by the potential that the audience may include those not so steeped in the thinking of stable isotopes. This calls to mind a historical note regarding Li isotopes. Readers of the early literature on the subject (beginning with Chan in 1987) will find papers that use δ6Li. Prior to 2000, using the now-accepted δ7Li notation was viewed as an unwanted usurpation by at least one prominent geochemist. Nevertheless, being clear is important, and although δ7Li was not the first notation employed, it follows stable isotope convention. We find that students have a hard enough time understanding isotope geochemistry, so to oppose the notation used in virtually all systems (positive values are isotopically heavier than negative values) invites confusion. Hence, our use of the ‰ is a further step to make this compilation clear for all.