Test well DO-CE 88 at Cambridge, Dorchester County, Maryland

Trapp, Henry, Jr.; Knobel, Leroy L.; Meisler, Harold; Leahy, P. Patrick

Abstract:

Test well DO-CE 88 at Cambridge, Maryland, penetrated 3,299 feet of unconsolidated Quaternary, Tertiary and Cretaceous sediments and bottomed in quartz-monzonite gneiss. The well was drilled to provide data for a study of the aquifer system of the northern Atlantic Coastal Plain. Twenty-one core samples were collected. Six sand zones were tested for aquifer properties and sampled for ground-water chemistry. Point-water heads were measured at seven depths. Environmental heads (which ranged from - 18.33 to + 44.16 feet relative to sea level)indicate an upward component of flow. A temperature log showed a maximum temperature of 41.9 degrees Celsius and a mean temperature gradient of 0.00838 degrees Celsius per foot. The water analyses delineated the freshwater-saltwater transition zone between 2,650 and 3,100 feet. The ground water changes progressively downward from a sodium bicarbonate to a sodium chloride character. Clays in the analyzed core samples belong to the montmorillonite and kaolinite groups, and mean cation exchange capacity ranged from 8.3 to 38.9 milliequivalents per 100 grams. Vertical and horizontal hydraulic conductivities measured in cores ranged from 1.5 x 10 6 to 1.3 feet per day and from 7.3 x 10 -6 to 1.3 feet per day, respectively, but the most permeable sands were not cored. Porosity was 1.5 percent in the quartz monzonite bedrock and ranged from 22.4 to 41 percent in the overlying sediments. Transmissivities from aquifer tests ranged from 25 to 850 feet squared per day; horizontal hydraulic conductivities ranged from.2.5 to 85 feet squared per day, and intrinsic permeabilities ranged from 0.8 to 23 micrometers squared. Fossils identified in core samples include palynomorphs, dinoflagellates, and foraminifers.

Genre:

USGS Numbered Series

ProdID:

746

Citation Author:

Trapp, Henry, Jr.; Knobel, Leroy L.; Meisler, Harold; Leahy, P. Patrick

Citation Contributing Office:

Citation Datum:

Citation Day:

Citation Edition:

Citation Editor:

Citation End Page:

Citation Issue:

Citation Keywords:

Citation Language:

ENGLISH

Citation Larger Work Title:

Citation LatN:

Citation LatS:

Citation LonE:

Citation LonW:

Citation Month:

Citation No Pagination:

Citation Number Of Pages:

Citation Online Only Flag:

Citation Phsyical Description:

iv, 48 p. :ill., maps ;28 cm.

Citation Projection:

Citation Public Comments:

Citation Publisher:

U.S. G.P.O.,

Citation Series:

Water Supply Paper

Citation Series Code:

WSP

Citation Series Number:

2229

Citation Search Results Text:

Test well DO-CE 88 at Cambridge, Dorchester County, Maryland; 1984; WSP; 2229; Trapp, Henry, Jr.; Knobel, Leroy L.; Meisler, Harold; Leahy, P. Patrick

Citation Start Page:

Citation Volume:

Citation Year:

1984

Type:

citation/reference

Text:

Test well DO-CE 88 at Cambridge, Dorchester County, Maryland; 1984; WSP; 2229; Trapp, Henry, Jr.; Knobel, Leroy L.; Meisler, Harold; Leahy, P. Patrick