Revision to Nomenclature of the Zarah Subgroup of the Kansas City Group (Pennsylvanian) in Kansas

This paper provides a summary review of proposed nomenclatural revisions to the Zarah Subgroup of the Kansas City Group (Pennsylvanian) in Kansas and outlines changes adopted by the Kansas Geological Survey. The Iola Limestone, which comprises in ascending order the Paola Limestone, Muncie Creek Shale, and Raytown Limestone Members, is now considered the basal formation of the Zarah Subgroup. We reinstate the overlying Liberty Memorial Shale as originally defined by Clair (1943) in the area of Kansas City, Missouri. We also restrict the Wyandotte Limestone to include only, in ascending order, the Frisbie Limestone, Quindaro Shale, and Argentine Limestone Members. Furthermore, the Lane Shale is restricted in use and encompasses all strata within the shale-dominated interval between the top of the Argentine Limestone Member of the Wyandotte Limestone and the base of the overlying Plattsburg Limestone. Within the revised Lane Shale, the KGS now formally recognizes, in ascending order, the Lower Farley Limestone, Middle Farley Shale, and Upper Farley Limestone Members. The Bonner Springs Shale is now demoted in rank and included as the uppermost member within the Lane Shale.

Geological characterization of the Patterson CO2 storage site from 3-D seismic data

Approximately 26 square miles of new 3-D seismic data were acquired in July 2019 over the Patterson Site (Kearny County, Kansas) to assess its potential for carbon dioxide (CO2) storage. Seismic interpretation revealed that the Patterson Site contains multiple structural closures that lie on uplifted fault blocks, bounded by two reverse faults that strike nearly perpendicular to each other. These faults offset Precambrian through Pennsylvanian sections, including several primary reservoir and seal intervals. Fault displacements are maximum at the Precambrian basement and decrease upward. Data indicated a range of structural and combination traps exists at the Patterson Site in the Cambrian-Ordovician Arbuckle through Mississippian Osagian reservoirs. The three-way closures along the NW–SE fault have structural relief of ~130 ft (40 m), and the four-way closures contain relief of ~60 ft (18 m). Erosional surfaces and multiple basement fractures also are observed on the top of the Precambrian. A Mississippian-aged incised valley system also was observed at the Patterson Site. The incised valleys formed during the Meramecian-Chesteran Stages with an incised depth up to 250 ft (76 m). The motion of the reverse faults likely captured existing meandering and linear channels, causing the current deeply incised morphology. The incised valleys observed at Patterson are similar in age, structural style, shape, incision depth, and seismic attribute properties to incised valleys observed by other workers at Pleasant Prairie South, Eubank, and Shuck oil fields (southwest Kansas). Further research should focus on estimating reactivation tendency and sealing characteristics of the reverse faults to evaluate the seal integrity of the saline reservoirs. This will reduce uncertainty concerning the risk of CO2 migration during injection and storage. Further reservoir description, modeling, and simulation are also underway to characterize the storage potential at the Patterson Site