INTRODUCTION

The Geological Society of America’s (GSA) membership is a demographic aggregate of individuals who join the Society, age as members, and eventually leave it either voluntarily or through death. GSA’s population structure bears the imprint of the major events that have shaped the geosciences during the past 85 years (the lifetimes of its membership). The current population structure also anticipates future changes in the Society’s membership. GSA provided the birth year, gender, and location (state or country) of active members in July 2006; the data analyzed here include only members residing in the United States (15,224 members; 85.4% of the Society’s total) to minimize demographic variations resulting from the varied social, political, and economic histories of multiple nationalities.

Manuscript received 28 June 2008; accepted 21 July 2008.

doi: 10.1130/GSATGW21A.1

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