This statement, adapted from the opening sequence of STAR TREK is may be an exaggeration, but I consider it not too far from the truth.
Shales contain the lion's share of earth history that is recorded in sedimentary rocks.
Understanding their deposition is key to the reconstruction of past oceans, landscapes, climates, and climatic cycles. Yet, whereas students of sandstones and carbonates have been able to learn a great deal about the deposition of these rocks from studying bedforms and sedimentary structures in the context of experimental data and direct observations in modern environments, the situation is not as fortunate when we examine our current knowledge concerning shales and mudstones. Basically I think that shales are fascinating rocks, and that there is much we can learn from them about earth history and geologic processes. Shales that I had an opportunity to study with this approach range in age from Proterozoic to Eocene and come from the Proterozoic Belt Supergroup of Montana, the Cambrian Wheeler Shale of Utah, the Ordovician Athens Shale of Alabama, the Devonian Chattanooga Shale of Tennessee, the Triassic Moenkopi Formation of Utah, the Posidonia Shale of Germany, the Mancos Shale of Utah, and the Green River Formation of Wyoming. In addition to my broad interest in shales, I am also curious about the formation of sedimentary mineral deposits and the diagenesis of sediments.