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Site content related to keyword: "Kent County"

Columbia Formation

Qcl

Yellowish- to reddish-brown, fine to coarse, feldspathic quartz sand with varying amounts of gravel. Typically cross-bedded with cross-sets ranging from a few inches to over three feet in thickness. Scattered beds of tan to reddish-gray clayey silt are common. In places, the upper 5 to 25 feet consists of grayish- to reddish-brown silt to very fine sand overlying medium to coarse sand. Near the base, clasts of cobble to small boulder size have been found in a gravel bed ranging from a few inches to three feet thick. Gravel fraction primarily quartz with lesser amounts of chert. Clasts of sandstone, siltstone and shale from the Valley and Ridge, and pegmatite, micaceous schist, and amphibolite from the Piedmont are also present. Fills a topographically irregular surface, is less than 50 feet thick, and is interpreted to be primarily a body of fluvial glacial outwash sediment (Jordan, 1964; Ramsey, 1997). Pollen indicate deposition in a cold climate during the middle Pleistocene (Groot and Jordan, 1999).

Turtle Branch Formation

Qtb

One to five feet of gray coarse sand and pebbles overlain by one to ten feet of tan to gray clayey silt to silty clay that is in turn overlain by three to five feet of fine to medium sand. Laterally, finer beds are less common away from Marshyhope Creek and the deposit is dominated by fine to medium sand with scattered beds of coarse to very coarse sand with pebbles. Sands are quartzose with some feldspar and laminae of opaque heavy minerals. Underlies a terrace with elevations ranging from 35 to 50 feet and is interpreted to be fluvial to estuarine in origin. Found in the Marshyhope Creek drainage basin in Kent County and more extensively along the Nanticoke drainage basin in Sussex County. Thickness ranges up to 20 feet closer to the valley of the Marshyhope and thins away from the river.

Lynch Heights Formation

Qlh

Heterogeneous unit of light-gray to brown to light-yellowish brown, medium to fine sand with discontinuous beds of coarse sand, gravel, silt, fine to very fine sand, and organic-rich clayey silt to silty sand. Upper part of the unit commonly consists of fine, well-sorted sand. Small-scale cross-bedding within the sands is common. Some of the interbedded clayey silts and silty sands are burrowed. Beds of shell are rarely encountered. Sands are quartzose and slightly feldspathic, and typically micaceous where very fine to fine grained. Unit underlies a terrace parallel to the present Delaware Bay that has elevations between 50 and 30 feet. Interpreted to be a fluvial to estuarine unit of fluvial channel, tidal flat, tidal channel, beach, and bay deposits (Ramsey, 1997). Overall thickness ranges up to 50 feet.

RI41 Hydrogeology and Geochemistry of the Unconfined Aquifer, West-Central and Southwestern Delaware

RI41 Hydrogeology and Geochemistry of the Unconfined Aquifer, West-Central and Southwestern Delaware

The unconfined aquifer is the major source of water supply in west-central and southwestern Delaware. The aquifer, which is composed of quartz sand, gravel, clay, and silt, ranges in thickness from 20 to 200 feet. The water table ranges from land surface to about 20 feet below land surface. Analyses of water from wells distributed throughout the area were used to study processes controlling the chemical quality of the water in the unconfined aquifer.

Scotts Corners Formation

Qsc

Heterogeneous unit of light-gray to brown to light-yellowish-brown, coarse to fine sand, gravelly sand and pebble gravel with rare discontinuous beds of organic-rich clayey silt, clayey silt, and pebble gravel. Sands are quartzose with some feldspar and muscovite. Commonly capped by one to two feet of silt to fine sandy silt. Laminae of opaque heavy minerals are common. Unit underlies a terrace parallel to the present Delaware River that has elevations less than 25 feet. Interpreted to be a transgressive unit consisting of swamp, marsh, estuarine channel, beach, and bay deposits. Climate during the time of deposition was temperate to warm temperate as interpreted from fossil pollen assemblages (Ramsey, 1997). Overall thickness of the unit rarely exceeds 20 feet.

Fish: Phlyum Chordata

Fish: Phlyum Chordata <br>Source:  PBS.org

While sampling the lower Miocene Calvert Formation at the Pollack Farm Site, 30 fossil fish taxa were collected, consisting of 24 cartilaginous and 6 osteichthyes fishes. The fossils found in the lower Miocene bed have similar characteristics to an equally aged Formation in southern Delaware suggesting deposition occured in a subtropical, shallow-water, near shore environment.

Insects and Crustaceans: Phylum Arthropoda

Insects and Crustaceans: Phylum Arthropoda <br>Source:  PBS.org

The majority of Arthropods recovered at the lower Miocene bed are from various species of crustaceans (lobsters, shrimp, barnacles). Fossils from crustaceans often consist of small body parts such as claws. However, crustaceans such as ghost shrimp (callichirus) tend to construct burrows that resemble lumpy tubes called Ophiomorpha. These corn-stalked resembling tunnels, are created from mud and depository waste to form burrows in which the creatures reside. In comparison to claws and pincher fossils, "trace fossils", such as Ophiomorpha tubes, are often commonly found in greater number than that of various body parts.

Bivalves: Phylum Mollusca, Class Bivalvia

Mollusca Bivalvia - Miocene Fossils <br>Source:  Wikimedia Commons

Clams, mussels, oysters, and scallops are members to the class Bivalvia (or Pelecypodia). Bivalves have two shells, connected by a flexible ligament, which encase and shield the soft vulnerable parts of the creature. All 15,000 known species of bivalves are aquatic in nature, with close to 80% being marine (saltwater environments).

Snails and Slugs: Phylum Mollusca, Class Gastropoda

Mollusca Gastropoda - Miocene Fossils<br>Source:  Wikimedia Commons

The Class Gastropoda includes the groups pertaining to snails and slugs. The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn. The shell of these creatures is often what is recovered in a fossil dig. Gastropods are by far the largest class of molluscs, comprising over 80% of all molluscs.

Miocene Fossils Overview

Miocene Fossils of Pollack Farm

Located in Kent County, Delaware, the Pollack Farm Site was a surprise to many to contain numerous fossils. The fossils discovered range from a simple Arthropod, small insect, to large vertebrates, such as sharks. In 1991, while Delaware Geological Survey staff collected earth minerals during a highway construction, they came across an upper shell bed full of molluscan fossils. As digging continued numerous fossils of various species and phylum were found.

Characterization of Tidal Wetland Inundation in the Murderkill River Estuary

Webbs Marsh, Murderkill River Estuary
Project Contact(s):

The project supports work by the Kent County Levy Court (Kent County) to evaluate the nutrient TMDLS for the tidal portion of the Murderkill River. The project will contribute to a more robust parameterization of river-marsh interaction in the water-quality model that is being developed for the Murderkill River by Kent County. The purpose of the project is to characterize the spatial and temporal inundation of a salt marsh in the Murderkill River Estuary and to determine the feasibility of using heat as a tracer of flow to characterize inundation of other marshes in the estuary.

Groundwater Resources of Sussex County (with an update for Kent County)

Project Contact(s):

This project is an integrated geologic/hydrologic study that will update our knowledge of the unconfined aquifers, confined aquifers, and groundwater resources of Sussex County. In addition, this project will utilize the results of recently completed study of the aquifer geology of Kent County (McLaughlin and Velez, 2005) to better define the groundwater resources of Kent County. The products to be produced by this study include aquifer depth and thickness maps and geologic cross sections for Sussex County. Products will also include a summary of basic hydrologic characteristics of aquifers in Kent and Sussex County and an analysis of water use for each aquifer.

OFR48 Results of the Domestic Well Water-Quality Study

OFR48 Results of the Domestic Well Water-Quality Study

The Delaware Geological Survey conducted a review of existing ground-water quality data collected from shallow (less than 100 feet deep) domestic water-supply wells and small public water-supply wells (serving fewer than 100 residents) to determine the extent to which toxic and carcinogenic compounds are present in the shallow ground water serving domestic water supply wells. These data were generated by several agencies including the Delaware Geological Survey, U.S. Geological Survey, Delaware Department of Natural Resources and Environmental Control, Delaware Division of Public Health Office of Drinking Water, and the Delaware Department of Agriculture Pesticide Management Program.

B18 Clay and Clay-Size Mineral Composition of the Cretaceous-Tertiary Section, Test Well Je32-04, Central Delaware

B18 Clay and Clay-Size Mineral Composition of the Cretaceous-Tertiary Section, Test Well Je32-04, Central Delaware

This study complements Delaware Geological Survey Bulletin No. 17 and deals exclusively with clays and clay-size minerals. The cored section at the location of Je32-04 has been subdivided into 25 clay zones on the basis of major changes in trends and degree of crystallinity of clay minerals. The composition of clay minerals varies from zone to zone. These clay minerals have been identified: kaolinite, berthierine, chlorite, illite, smectite, chlorite/smectite, illite/smectite, glauconite/smectite, and glauconite pellets. Other minerals present in the section include: zeolites (clinoptilolite-heulandite), gypsum, and elemental sulfur.

B17 Geological Studies of Cretaceous and Tertiary Section, Test Well Je32-04, Central Delaware

B17 Geological Studies of Cretaceous and Tertiary Section, Test Well Je32-04, Central Delaware

A cored well 1,422 feet (433 meters) deep drilled two miles southeast of Dover is the basis for this integrated study of the lithology and paleontology of the Cretaceous-Tertiary section in central Delaware. The section is subdivided into lithostratigraphic, biostratigraphic, chronostratigraphic, and heavy mineral units. Data and results are presented on a common base in three plates.

B16 Ground-Water Resources of the Piney Point and Cheswold Aquifers in Central Delaware as Determined by a Flow Model

B16 Ground-Water Resources of the Piney Point and Cheswold Aquifers in Central Delaware as Determined by a Flow Model

A quasi three-dimensional model was constructed to simulate the response of the Piney Point and Cheswold aquifers underlying Kent County, Delaware to ground-water withdrawals. The model included the Magothy, Piney Point, Cheswold, and unconfined aquifers, and was calibrated using historical pumpage and water-level data. Model calibration was accomplished through the use of both steady-state and transient-state simulations.

B15 Digital Model of the Unconfined Aquifer in Central and Southeastern Delaware

B15 Digital Model of the Unconfined Aquifer in Central and Southeastern Delaware

The unconfined aquifer in central and southeastern Delaware occurs as a southward-thickening blanket of fine to coarse sand, and is recharged almost totally by precipitation and discharge is principally by seepage to streams, bays, and the ocean.

RI29 Digital Model of the Piney Point Aquifer in Kent County, Delaware

RI29 Digital Model of the Piney Point Aquifer in Kent County, Delaware

A two-dimensional digital model was developed to simulate the effects of increased pumping on the Piney Point aquifer in Kent County, Delaware. The calibrated digital model was used to predict water-level declines as the aquifer responded to both changes in the distribution and increases in the quantity of pumping to the year 2000.

Coastal Plain Rock Units (Stratigraphic Chart)

The geology of Delaware includes parts of two geologic provinces: the Appalachian Piedmont Province and the Atlantic Coastal Plain Province. The Piedmont occurs in the hilly northernmost part of the state and is composed of crystalline metamorphic and igneous rocks. This chart summarizes the age and distribution of the geologic units that are recognized in the state by the Delaware Geological Survey.

HM11 Ground-Water Recharge Potential Kent County, Delaware

Ground-Water Recharge Potential Kent County, Delaware

The ground-water recharge potential map of Kent County, Delaware, is a compilation of 1:24,000-scale maps of the water-transmitting properties of sediments in the interval between land surface and 20 ft below land surface. Water-transmitting properties are a key factor in determining the amount of water that recharges Delaware’s aquifers and the susceptibility of aquifers used as sources of water supply to contamination from near-surface pollutant sources. The mapping methodology was developed by Andres (1991) for the geologic characteristics of the Atlantic Coastal Plain portion of Delaware. Mapping and methods development started in 1990 and the final maps were completed in 2002 (Andres et al., 2002). Additional information about the map and methodology and a list of cited references are presented on the reverse side. The mapping program was funded by the Delaware Department of Natural Resources and Environmental Control and the Delaware Geological Survey.