Pg. 33. Jasper Creek shales in Graford Formation. Shales with 4 sandstones, each 10 to 15 feet thick. The shales are light-colored with yellow and brown beds; are often sandy or carry thin beds of ripple-marked sandstone flags. The sandstones pinch out to northeast and the shales change to limestone on north side of Trinity River. Thickness 300+ feet. Lie in valley of Jasper Creek and on the slopes of escarpment to west, Wise County, central northern Texas. Are exact stratigraphic equivalent of Chico Ridge limestone to north of Trinity River. Contain characteristic Graford fossils and belong in that formation. [Age is Pennsylvanian.]

Source: US geologic names lexicon (USGS Bull. 896, p. 1041).

Mapped as a formation of Canyon Group in the southeastern part of mapped area, north-central TX (ascending): Palo Pinto Formation, Wolf Mountain Shale, Winchell Limestone, Placid Shale, Ranger Limestone, Colony Creek Shale, and Home Creek Limestone. Farther east, Canyon is divided into (ascending): Willow Point Formation, Jasper Creek Formation with its Chico Ridge Limestone [unranked], Ventioner Formation, Ranger Limestone, and Colony Creek Shale. Present in southeastern Jack Co, on Fort Worth syncline, and extends onto adjacent Sherman sheet. Partially equivalent to Wolf Mountain Shale. Mapped with Chico Ridge Limestone [unranked]; the Chico Ridge (not present on this sheet) is present on the adjacent Sherman sheet. Consists of shale, gray, weathers tan, silty and sandy, locally abundant ferruginous nodules, sparsely fossiliferous, contains numerous flaggy sandstone beds bearing ripple marks and horizontal laminae, local fine-grained channel-fill bodies in upper part with soft-sediment-deformed beds and fossil plant debris. Separately mapped is an unnamed sandstone. Thickness of portion of Jasper Creek within map area is about 90 ft; entire formation is depicted on Sherman sheet. Age is Missouri (Late Pennsylvanian). Geologic map.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Pamphlet [p. 14]. Jasper Creek Formation of Canyon Group. [Intertongues with beds of partly equivalent Chico Ridge Limestone of Canyon Group, notably Rock Hill Limestone Member, which separates upper and lower parts of Jasper Creek Formation. Underlies and in places intertongues with Devils Den Limestone Member of Chico Ridge. Upper part of formation (Jasper Creek beds; between the Devils Den and Rock Hill), gray, reddish-gray, greenish-gray, tan, silty, sandy, fossiliferous shale with thin beds of sandstone and siltstone; includes separately mapped sandstone units, descending, ss5, ss4, and ss3. Lower part of formation (Lake Bridgeport shales; beneath the Rock Hill), gray, tan- and yellowish-brown-weathering shale, locally containing thin fossiliferous limestone lentils; includes separately mapped sandstone units, ss2 and ss1.] Total thickness of formation 310 to 330 feet. Lies above Willow Limestone Member of /Willow Point Formation of Canyon Group. = lower part of Wolf Mountain Shale and Palo Pinto Formation exposed in adjacent Wichita Falls-Lawton sheet. Age is Late Pennsylvanian (Missourian).
[Mapped in Lake Bridgeport area, Jack and Wise Cos., central northern TX; western edge of map sheet. Rocks previously (1967 ed. of map) mapped as Jasper Creek Shale Member of Graford Formation. See also adjacent Wichita Falls-Lawton sheet, Texas Geol. Atlas, 1987.]

Source: Publication.