Geologic map of the Fredericksburg 30' x 60' quadrangle, Virginia and Maryland
No abstract available.
Virginia, Maryland↗
Geology topics
L. W. Ward
Publications and source records attributed to L. W. Ward.
A New Species of Pulvinites (Mollusca: Bivalvia) from the Upper Paleocene Paspotansa Member of the Aquia Formation in Virginia
Pulvinites lawrencei n.sp. is described from the upper Paleocene (Landenian Stage) Paspotansa Member of the Aquia Formation in Stafford County, Virginia. This is the first report of a member of the pteriacean family Pulvinitidae in the Tertiary on either side of the Atlantic, the only other post-Mesozoic records of Pulvinites being in the Paleocene of California and the present-day Pacific off southeast Australia. The stratigraphic setting and co-occurring molluscan assemblage of the new species indicate shallow-shelf, open-marine conditions with near normal salinities.
Journal of Paleontology↗
Outline of tertiary stratigraphy and depositional history of the U.S. Atlantic Coastal Plain
No abstract available.
Book chapter↗
Age of the Comfort Member of the Castle Hayne Formation, North Carolina
The biostratigraphic and chronostratigraphic position of the Comfort Member of the Castle Hayne Formation has been the subject of much debate. At the Martin-Marietta Quarry at Castle Hayne, New Hanover County, North Carolina, the planktic foraminifers indicate an assignment within an interval of the uppermost Turborotalia frontosa Zone to the Turborotalia pomeroli Zone. The calcareous nannofossils indicate an assignment to the middle part of the Chiasmolithus solitus Zone. The dinocyst data indicate placement in the upper part of the Kisselovia coleothrypta Zone of Costa and Downie. These zonal units are considered to be within the middle Eocene of international usage, and, on the basis of the time scale used in this paper, the Chiasmolithus solitus Zone represents a time interval of 42.1 to 45.4 megaannums (Ma). This differs significantly from a Rb/Sr glauconite date of 34.8 ± 1.0 Ma previously obtained at the same locality.
North Carolina↗
Biostratigraphy and paleoecology of lower Paleozoic, upper Cretaceous, and lower Tertiary rocks in U.S. Geological Survey New Madrid test wells, Southeastern Missouri
The paleontology and biostratigraphy of Tertiary, Cretaceous, and Paleozoic rocks in the upper Mississippi embayment are incompletely known because marine fossils are only locally present in these rocks. This study concerns material from two U.S. Geological Survey test wells drilled in New Madrid County, southeastern Missouri, as part of earthquake hazard studies in the northern Mississippi Embayment. Test well1 sampled lower Tertiary strata to a depth of 146ft; these strata were found to be late Eocene in age on the basis of sporomorphs. Test well1-X, 29ft northwest of well1, provided cuttings and cores from lower Tertiary, Upper Cretaceous, and lower Paleozoic rocks to a total depth of 2,316 ft below the Kelly bushing (at an altitude of 288 ft). Lithologic evidence suggests that the base of the Jackson Formation may be at 270 ft, but sporomorphs indicate that the base of the Jacksonian Stage (upper Eocene) is possibly at a depth of about 350ft in test well1-X. Lithologic units of the Claibornian Stage (middle Eocene) here consist of the Cockfield(?) and Cook Mountain(?) Formations and Memphis Sand, in descending order. The Claibornian could not be subdivided using sporomorphs from cuttings, but sporomorphs show that the top of the Sabinian Stage (top of the lower Eocene) is at about 1,055 ft; lithologically, the top of the Wilcox Group (top of the Flour Island Formation) is at 1,048 ft. Sporomorphs suggest that the top of the lower Sabinian (top of the Paleocene) is within the Flour Island Formation at about 1,105 ft. The next major lithologic break, the top of the Fort Pillow Sand at 1,186 ft, does not coincide with any detectable biostratigraphic boundary. Lithologically, the interval from 1,339 to 1,377 ft may belong to the Old Breastworks Formation; dinoflagellates from cuttings indicate that this interval is likely to be late Midwayan in age and, therefore, correlative with the Naheola Formation of the eastern Gulf Coast. The Porters Creek Clay extends from a probable top at 1,377 ft to 1,691 ft, and the base of the underlying Clayton Formation (Tertiary-Cretaceous contact) is at 1, 703 ft. Calcareous nannofossils, dinoflagellates, foraminifers, mollusks, ostracodes, and sporomorphs from continuous cores of the Porters Creek Clay and Clayton Formation indicate that the upper half of the Porters Creek correlates with the upper part of the same formation or perhaps partly with slightly younger rocks in the eastern Gulf Coast, the lowermost Porters Creek appears to correlate with the upper part of the Clayton Formation of the eastern Gulf Coast and with the Kincaid Formation of Texas, and the thin Clayton of the test well probably correlates with only the lower part of the thicker Clayton of the eastern Gulf Coast. Sporomorphs from McNairy Sand (Upper Cretaceous) cores indicate Maestrichtian and perhaps latest Campanian Age. Lower Paleozoic dolostone from 2,023 ft to total depth at 2,316 ft is barren of identifiable fossils except for a probable fragment of the fish Anatolepis; the dolostone is probably Late Cambrian in age. The McNairy Sand of New Madrid well 1-X seems to have been deposited in nonmarine to nearshore marine environments; the Clayton Formation and lower part of the Porters Creek Clay were deposited under marine conditions during an early Paleocene marine transgression. A major regression followed that continued through the end of Porters Creek time and perhaps into Naheola (late Midwayan) time; the Sabinian, Claibornian, and Jacksonian strata in southeastern Missouri were deposited primarily or entirely in nonmarine environments.
Missouri↗