ADVANCEMENTS IN UNDERSTANDING THE NEOPROTEROZOIC AND EARLY PALEOZOIC STRATIGRAPHY IN WESTERN LAURENTIA: A SESSION RECOGNIZING THE ACHIEVEMENTS OF JOHN D. COOPER

Few people have played such an important role in deciphering the early history of the Cordilleran margin as John D. Cooper. In the last thirty years, a vast literature has developed around the strings of events surrounding the Precambrian-Cambrian boundary, from Snowball Earth hypotheses, to the Ordovician radiation and extinction. Much of John's research has landed within this critical interval in Earth history, and his contributions have added key insight to many of the events spanning this 300 million year time frame. John has achieved this with an armory of principally undergraduate student "colleagues," whose intellectual enrichment was an important focus of the research. One resonant theme developed in John's research has been the cornerstone contribution of quality paleoenvironmental analysis in interpreting the stratigraphic record. Such data has strongly impacted broader lithologic and sequence correlations, as well as deciphering a detailed relative sea-level rise and fall record. His results began with detailed analysis of the Cambrian Nopah Formation in the Death Valley region, which culminated in a highly sought after SEPM volume and field guide entitled "Cavalcade of Carbonates." From there John spent a number of years working with students on primarily clastic units spanning the Precambrian-Cambrian boundary, with results impacting the interpretation of rifting events leading to the formation of the Cordilleran margin and regional to global relative sea-level change. John's most current research has centered on karstification and sequence stratigraphy in Ordovician carbonates as part of a broader project unraveling Ordovician events in the Cordillera. Many individuals have worked in this region, but few have developed the depth and breadth of knowledge John has by choosing to understand a large part of the stratigraphic section in such detail. This session comes in honor of John's many contributions, but it is hardly a retrospective because, even in retirement, some of the most important "new perspectives" are his.