GEOLEX

Summary of Citation: Hornerstown

Publication:
Clark, W.B., 1907, The classification adopted by the U.S.
   Geological Survey for the Cretaceous deposits of New Jersey,
   Delaware, Maryland, and Virginia, IN Notes from the Geological
   Laboratory, 1906-1907: Johns Hopkins University Circular,
   no. 7, p. 1-4

Usage in Publication:
Hornerstown marl*

Modifications:	Geologic Province:	Dominant Lithology:
Named	Atlantic Coast basin	Marl

Summary:
Term Hornerstown marl is here proposed to replace Sewell, which is preoccupied. Unit is basal formation of Rancocas group. Underlies Vincentown sand. Early Eocene age assigned.

Summary of Citation: Hornerstown

Publication:
Fox, S.K., Jr. and Olsson, R.K., 1955, Stratigraphy of Late
   Cretaceous and early Tertiary formations in New Jersey [abs.]:
   Journal of Paleontology, v. 29, no. 4, p. 736

Usage in Publication:
Hornerstown sand

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Atlantic Coast basin

Summary:
Stratigraphic evidence indicates an unconformity between Cretaceous and Tertiary formations in NJ. Hornerstown rests successively from northeast to southwest on Tinton, Red Bank, and Navesink formations. In each case, the Hornerstown lies upon a weathered surface, and basal few feet contain fragments of the underlying formation.

Summary of Citation: Hornerstown

Publication:
Miller, H.W., Jr., 1956, Correlation of Paleocene and Eocene
   formations and Cretaceous-Paleocene boundary in New Jersey:
   American Association of Petroleum Geologists Bulletin, v.
   40, no. 4, p. 722-736

Usage in Publication:
Hornerstown formation

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Atlantic Coast basin

Summary:
Formation correlated with midway stage (Paleocene) of Gulf Coast. Presence of "middle greensand" unit between Navesink (Cretaceous) and Hornerstown formation recognized, and it is suggested that this is southwestward extension of Red Bank formation (Cretaceous).

Summary of Citation: Hornerstown

Publication:
Loeblich, A.R., Jr. and Tappan, Helen, 1957, Correlation of the
   Gulf and Atlantic Coastal Plain Paleocene and lower Eocene
   formations by means of planktonic Foraminifera: Journal of
   Paleontology, v. 31, no. 6, p. 1109-1137

Usage in Publication:
Hornerstown formation

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Atlantic Coast basin

Summary:
Age of the Hornerstown is Paleocene (Danian-Landenian). Determination made on basis of foraminiferal studies. Overlies Monmouth group; underlies Vincentown formation. Report summarizes opinions of several workers.

Summary of Citation: Hornerstown

Publication:
Richards, P.W., 1957, Geology of the area east and southeast of
   Livingston, Park County, Montana, IN Contributions to general
   geology, 1955: U.S. Geological Survey Bulletin, 1021-L, p.
   L385-L438

Usage in Publication:
Hornerstown marl

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits Overview	Atlantic Coast basin

Summary:
Hornerstown marl lies disconformably on Navesink marl in southern NJ. In Monmouth Co. where Red Bank and Tinton formations are present, relationship may be conformable. Consists of glauconite with clay and sand; resembles parts of Navesink, but is distinguished from it by its more sandy nature. Thickness at outcrop 30 ft; average dip 30 ft per mi. Exact age uncertain; recent work on microfossils has shown formation should be regarded as Paleocene. Geographically extended into DE.

Summary of Citation: Hornerstown

Publication:
Owens, J.P. and Minard, J.P., 1962, Pre-Quaternary geology of
   the Columbus quadrangle, New Jersey: U.S. Geological Survey
   Geologic Quadrangle Map, GQ-160, 1 sheet, scale 1:24,000

Usage in Publication:
Hornerstown Sand*

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Atlantic Coast basin

Summary:
Name of unit changed from Marl to Sand.

Summary of Citation: Hornerstown

Publication:
Minard, J.P., 1974, Geology of the Betterton quadrangle, Kent
   County, Maryland, and a discussion of the regional stratigraphy:
   U.S. Geological Survey Professional Paper, 816, 27 p.

Usage in Publication:
Hornerstown Sand*

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits	Atlantic Coast basin

Summary:
Hornerstown Sand of Rancocas Group is geographically extended into northeastern MD.

Summary of Citation: Hornerstown

Publication:
Conant, L.C., 1990, The coastal plain of Cecil County, IN Higgins,
   M.W., and Conant, L.C., The geology of Cecil County, Maryland:
   Maryland Geological Survey Bulletin, no. 37, p. 118-183

Usage in Publication:
Hornerstown Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits Overview	Atlantic Coast basin

Summary:
Hornerstown "is remarkable for its uniformity in composition and thickness over long distances." Unit has been traced from Raritan Bay, NJ, to eastern MD (125 mi) and is approximately 20 ft thick for the entire distance. In a measured section at Georgetown Post Office in Fredericktown, Cecil Co., the Hornerstown is 19.0 ft of fine to medium, olive-gray glauconite sand containing about 80 percent glauconite. Color is somewhat lighter at top because of weathering. Lower 2 ft contain abundant nodules of goethite. Unconformably overlies unnamed upper portion of Monmouth Group. Underlies Aquia Formation. [Apparently not assigned to Rancocas Group in this report.]

Summary of Citation: Hornerstown

Publication:
Gallagher, W.B., 1992, Geochemical investigations of the
   Cretaceous/Tertiary boundary in the Inversand pit, Gloucester
   County, New Jersey: New Jersey Academy of Science, The
   Bulletin, v. 37, no. 1, p. 19-24

Usage in Publication:
Hornerstown Formation

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Atlantic Coast basin

Summary:
Cretaceous/Tertiary boundary is within the basal portion of the Hornerstown Formation in the Inversand pit in the town of Sewell, Mantua Township, NJ. Boundary is illustrated just above the "Main Fossiliferous Layer" of the Hornerstown, which contains the last remains of Cretaceous fauna including a concentration of skeletal materials interpreted as the mass mortality layer. Geochemical investigations, however, revealed no significant differences in toxic metal levels between the Navesink and overlying Hornerstown, though previous studies of this stratigraphic interval in other areas have documented high levels of iridium.

Summary of Citation: Hornerstown

Publication:
Gallagher, W.B., 1993, The Cretaceous/Tertiary mass extinction
   event in the northern Atlantic Coastal Plain: The Mosasaur,
   Journal of the Delaware Valley Paleontological Society, v.
   5, p. 75-129

Usage in Publication:
Hornerstown Formation

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Atlantic Coast basin

Summary:
Hornerstown Formation of Rancocas Group is a grayish olive green to dusky yellowish green massive, burrowed, poorly to moderately sorted, medium to fine-grained clayey and virtually pure glauconite sand. Clay content increases downdip. Thickness ranges from 6 to 9 m. Contains a Cretaceous marine fauna at its base, but in the middle and at the top has a Tertiary assemblage. Basal fossiliferous layer has yielded a late Cretaceous avifauna according to Olson and Parris (1988). Unit extends from Raritan Bay in the northeast to the Sassafras River on the eastern shore of the Chesapeake Bay in MD. Exposures of Hornerstown are now limited largely to streambank outcrops, temporary excavations, and the single remaining marl pit in Sewell, Gloucester Co. Age is late Maastrichtian and Danian.

Summary of Citation: Hornerstown

Publication:
Hansen, H.J. and Drummond, D.D., 1994, Upper Cretaceous and
   Tertiary stratigraphy of core-hole Ken-Bf 180 clarifies
   aquifer nomenclature in Kent County, Maryland, IN Schultz,
   A.P., and Rader, E.K., eds., Studies in eastern energy and
   the environment: Virginia Division of Mineral Resources
   Publication, no. 132, p. 50-56, Also, 1994, American Association
   of Petroleum Geologists, Eastern Section Special Volume,
   Williamsburg, VA, September 19-21, 1993.

Usage in Publication:
Hornerstown Formation

Modifications:	Geologic Province:	Dominant Lithology:
Overview Biostratigraphic dating	Atlantic Coast basin

Summary:
Hornerstown Formation occupies the interval from 204.2 ft to 109.1 ft in the core-hole Ken-Bf 180. Unit is considered largely, if not entirely, early Paleocene (Danian) in age. Age is bracketed by the last occurrence of Maastrichtian ostracodes at 204.2 ft and the first occurrence of OLENEOTHYRIS HARLANI (brachiopod) at about 109 ft. Described as a massive, fine to medium, locally coarse, glauconitic sand. Hornerstown is widely distributed in central and eastern Kent Co. In eastern Kent Co., unit is thinner and more clayey than elsewhere in the county. Sharply overlies Late Cretaceous Severn Formation of Monmouth Group and underlies late Paleocene Aquia Formation.

Summary of Citation: Hornerstown

Publication:
Bybell, L.M. and Self-Trail, J.M., 1994, Evolutionary,
   biostratigraphic, and taxonomic study of calcareous nannofossils
   from a continuous Paleocene-Eocene boundary section in New
   Jersey: U.S. Geological Survey Professional Paper, 1554, 36
   p.

Usage in Publication:
Hornerstown Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified Biostratigraphic dating	Atlantic Coast basin

Summary:
Hornerstown Formation in NJ shown on several lithologic sections as early Paleocene age, corresponding to calcareous nannofossil zones NP 3 and 4. Report includes fossil lists and several stratigraphic/lithologic sections.

Summary of Citation: Hornerstown

Publication:
Owens, J.P., Sugarman, P.J., Sohl, N.F., Parker, R.A., Houghton,
   H.F., Volkert, R.A., Drake, A.A., Jr. and Orndorff, R.C.,
   unpub., Bedrock geologic map of New Jersey, central sheet:
   U.S. Geological Survey Miscellaneous Investigations Series
   Map, I-__, scale 1:100,000, Also, 1995, U.S. Geological Survey
   Open-File Report, OF-95-253, 60 p. (incl. geologic map, scale
   1:100,000).

Usage in Publication:
Hornerstown Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Atlantic Coast basin

Summary:
The Hornerstown Formation in NJ consists of massive, extensively bioturbated, locally clayey, dark-gray to dusky-green, fine- to medium-grained, glauconite sand. Thickness is 2 to 7 m in outcrop and rarely exceeds 8 m in the subsurface. Unconformably overlies the Tinton Formation in the north, Red Bank Formation in the northwest and west-central areas, and the Navesink Formation in the west-central and southern areas. Unconformably underlies the Vincentown Formation. The Hornerstown is of early Paleocene (Danian) age.