Richard D. Fritz, William A. Morgan, Susan Longacre, James R. Derby, Charles A. Sternbach, 2012. "Introduction", Great American Carbonate Bank: The Geology and Economic Resources of the Cambrian—Ordovician Sauk Megasequence of Laurentia, James Derby, Richard Fritz, Susan Longacre, William Morgan, Charles Sternbach
Download citation file:
The great American carbonate bank (GACB) refers to a system of carbonates and related siliciclastics that were deposited on and around the Laurentian continent during the Cambrian, Early Ordovician, and earliest Middle Ordovician. This laterally continuous and diverse sequence has been assigned different sets of formation and group names across the GACB, such as Arbuckle, Beekmantown, Bonanza King, Deadwood, Ellenburger, El Paso, Knox, Prairie du Chien, and Potsdam (to name just a few of the more widely used), but characteristic lith of acies and fauna that are found throughout North America, Greenland, northwestern Scotland, Svalbard, and the pre-Cordillera of Argentina are observed.
Fundamental to our understanding of the components of the GACB is the biostratigraphy that ties the disparate parts into a cohesive whole. The importance of biostratigraphy was recognized early on by Jim Wilson, and he worked to integrate it with lithostra-tigraphy, sedimentology, bio facies, cyclic sedimentation, and sequence stratigraphy.
Today, biostratigraphy continues to play a key function in devising a correlation framework across the GACB and in unraveling its evolution. Biostratigraph-ic zonation has advanced considerably since the days when Sloss et al. (1949) coined the term “Sauk sequence” and Palmer (1981) subdivided the Sauk into three subdivisions. It is now possible to identify more than 20 biostratigraphic zones within the Sauk succession for the Laurentian continent (with finer subdivision possible on a more local basis) using mostly trilobites and conodonts. This finer biostratigraphic zonation has led to an increased recognition of events that can
Figures & Tables
Great American Carbonate Bank: The Geology and Economic Resources of the Cambrian—Ordovician Sauk Megasequence of Laurentia
The Great American Carbonate Bank (GACB) comprises the carbonates (and related siliciclastics) of the Sauk megasequence, which were deposited on and around the Laurentian continent during Cambrian through earliest Middle Ordovician, forming one of the largest carbonate-dominated platforms of the Phanerozoic. The Sauk megasequence, which ranges upwards of several thousand meters thick along the Bank's margin, consists of distinctive Lithofacies and fauna that are widely recognized throughout Laurentia. A refined biostratigraphic zonation forms the chronostratigraphic framework for correlating disparate outcrops and subsurface data, providing the basis for interpreting depositional patterns and the evolution of the Bank. GACB hydrocarbon fields have produced 4 BBO and 21 TCFG, mostly from reservoirs near the Sauk-Tippecanoe unconformity. The GACB is also a source of economic minerals and construction material and, locally, serves as either an aquifer or repository for injection of waste material. This Memoir comprises works on biostratigraphy, ichnology, stratigraphy, depositional facies, diagenesis, and petroleum and mineral resources of the GACB. It is dedicated to James Lee Wilson who first conceived of this publication and who worked on many aspects of the GACB during his long and illustrious career.