ABSTRACT Stratigraphy has been a descriptive science for most of its history. Recently, thanks to the development of the mechanis- tic view of Earth embodied in plate tectonics and to improve- ments in our understanding of sediment dynamics, the strati- graphic community has developed a first generation of quantitative models for the filling of basins and the formation of stratigraphic patterns. How do we test such models? The field is the ultimate repository of information, but exposure is limited, and it is often difficult to constrain key governing variables independently. We have developed a novel experi- mental basin—nicknamed Jurassic Tank—that allows us to produce experimental stratigraphy under precisely controlled and monitored conditions of sediment supply, subsidence, base-level variation, and transport mechanics. The unique feature of the basin is a fully programmable subsiding floor. In the first application of the system, we looked for evidence of decoupling (out-of-phase behavior) between shoreline and base level, as has been predicted by some recent strati- graphic models. We found little support for this idea, but the results demonstrate the potential that experiments have for complementing field and theoretical studies of the filling of sedimentary basins. Before you read this, try solving the problem posed in Figure 1. INTRODUCTION The central goal of sedimentary geology is to interpret the history of Earth’s surface from sedimentary rocks. We develop competing hypotheses, debate, discuss, and compare, but un- like areas of science that deal in accessible time and space scales, in sedimentary geology it is often difficult to determine unambiguously who is right. The ultimate source of truth—the stratigraphic record itself—is like a fragmentary manuscript written in a long-forgotten language. Deposits are imperfectly exposed and hard to date, seismic images are highly filtered and expensive, and the precise sequence of events that pro- duced real-world stratigraphy usually cannot be determined independently. Trying to understand the language of sedi- ments using rocks alone would be like trying to understand Russian by opening War and Peace to the middle and staring at the pages. Sedimentary geologists have long recognized this and sought Rosetta stones for the stratigraphic record through Experimental Stratigraphy Chris Paola, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414, USA, and Department of Geology & Geophysics, University of Minnesota, Minneapolis, MN 55455-0219, USA Jim Mullin and Chris Ellis, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414, USA David C. Mohrig, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA John B. Swenson, Department of Geological Sciences and Large Lakes Observatory, University of Minnesota, Duluth, MN 55812, USA Gary Parker, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414 USA Tom Hickson, Department of Geology, University of St. Thomas, St. Paul, MN 55105, USA Paul L. Heller, Department of Geology & Geophysics, University of Wyoming, Laramie, WY 82071, USA Lincoln Pratson, Earth and Ocean Sciences, Duke University, Durham, NC 27708-0230, USA James Syvitski, Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309-0450, USA Ben Sheets and Nikki Strong, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414, USA, and Department of Geology & Geophysics, University of Minnesota, Minneapolis, MN 55455-0219, USA Figure 1. Can you interpret this panel? It shows a section of basin sed- iment taken parallel to transport (i.e., a dip section), with flow from right to left. Darker material is lighter and hence more mobile. Distal part of deposit was formed under water, and proximal part is fluvial. Break between light and dark material is a good indicator of shoreline position. The challenge: Deduce history of sediment supply, subsi- dence, and base level for this section using only information above and geometry of the preserved deposits. Answer is given in Figure 5. 4 JULY 2001, GSA TODAY