Bryn Mawr Formation
Reddish-brown to yellowish-brown silty quartz sand to sandy silt that interfingers with medium to coarse clayey sand with gravel. Sand fraction, where a sandy silt, is fine- to very fine-grained and angular to subangular. Iron-cemented zones are common. Gravel fraction is primarily quartz. Sands are quartzose with minor amounts of weathered feldspar. Opaque heavy minerals form up to 3 percent of the sand fraction. Unit ranges up to 70 ft thick but generally less than 30 ft thick and commonly less than 10 ft thick. Surface forms a distinctive terrace that has elevations between 350 ft and 425 ft, and it overlies saprolite of the Piedmont rocks. No macrofossils have been recovered. Fossil pollen from the York Pit in Cecil County, Maryland (Pazzaglia, 1993; unpublished DGS data) indicate a Miocene age. Owens (1999) considered the unit late Oligocene in Pennsylvania.
SP4 Generalized Geologic Map of Delaware
The Generalized Geologic Map of Delaware is a brief summary for general use indicating the major types and locations of rocks present throughout the State, and their interrelationships. The map is preliminary as it is a first step in a continuing program of detailed geologic mapping. It is based upon many existing sources of data; additional detail may be found in the references listed.
GM13 Geologic Map of New Castle County, Delaware
This map shows the surficial geology of New Castle County, Delaware at a scale of 1:100,000. Maps at this scale are useful for viewing the general geologic framework on a county-wide basis, determining the geology of watersheds, and recognizing the relationship of geology to regional or county-wide environmental or land-use issues. This map, when combined with the subsurface geologic information, provides a basis for locating water supplies, mapping ground-water recharge areas, and protecting ground and surface water. Geologic maps are also used to identify geologic hazards, such as sinkholes and flood-prone areas, to identify sand and gravel resources, and for supporting state, county, and local land-use and planning decisions.
- alluvial deposits
- Appalachian Piedmont
- Ardentown Granitic Suite
- Atlantic Coastal Plain
- Baltimore Gneiss
- Barley Mill Gneiss
- Brandywine Blue Gneiss
- Bridgeton Formation
- Bringhurst Gabbro
- Bryn Mawr Formation
- Calvert Formation
- Chesapeake and Delaware Canal
- Christianstead Gneiss
- Cockeysville Marble
- Columbia Formation
- Cretaceous Period
- cross-sections
- Delaware Bay Group
- dredge disposal deposits
- Englishtown Formation
- Faulkland Gneiss
- fill
- Holocene
- Hornerstown Formation
- Iron Hill Gabbro
- Lynch Heights Formation
- Magothy Formation
- Manasquan Formation
- mapping
- Marcus Hook
- marsh deposits
- Marshalltown Formation
- Merchantville Formation
- Metapyroxenite and metagabbro (undifferentiated)
- Middletown
- Mill Creek Metagabbro
- Miocene
- Mount Laurel Formation
- Navesink Formation
- Neogene
- New Castle County
- Newark
- Odessa
- Old College Formation
- Oligocene
- Pegmatite
- Pennsylvanian Period
- Perkins Run Gabbronorite Suite
- Permian Period
- Pliocene
- Potomac Formation
- Quaternary Period
- Rockford Park Gneiss
- rocks
- Scotts Corners Formation
- Serpentinite
- Setters Formation
- Shark River Formation
- STATEMAP
- surficial geology
- swamp deposits
- undrained depression deposits
- Upper Cretaceous
- upper Eocene
- upper Holocene
- upper Pleistocene
- upper Pliocene
- Vincentown Formation
- Wilmington
- Wilmington Complex
- Wissahickon Formation
- Carboniferous Period
- Eocene
- Jurassic Period
- Lower Cretaceous
- lower Holocene
- lower Pliocene
- middle Eocene
- middle Pleistocene
- Miocene
- Mississippian Period
- Paleogene
- Pleistocene
- Tertiary Period
- upper Miocene
- Devonian Period
- lower Eocene
- lower Pleistocene
- middle Miocene
- Paleocene
- Triassic Period
- lower Miocene
- Silurian Period
- Ordovician Period
- Cambrian Period
- Mesozoic Era
- Paleozoic Era
- Precambrian
DGS Geologic Map No. 13 (New Castle County) Dataset
This dataset contains the geologic polygons used for the creation of DGS Geologic Map 13. This dataset shows the surficial geology of New Castle County, Delaware, at a scale of 1:100,000.
- Appalachian Piedmont
- ArcGIS
- Ardentown Granitic Suite
- Atlantic Coastal Plain
- Baltimore Gneiss
- Barley Mill Gneiss
- Brandywine Blue Gneiss
- Bridgeton Formation
- Bringhurst Gabbro
- Bryn Mawr Formation
- Calvert Formation
- Chesapeake and Delaware Canal
- Christianstead Gneiss
- Cockeysville Marble
- Columbia Formation
- cross-sections
- Delaware Bay Group
- dredge disposal deposits
- Englishtown Formation
- Faulkland Gneiss
- fill
- Hornerstown Formation
- Iron Hill Gabbro
- Lynch Heights Formation
- Magothy Formation
- Manasquan Formation
- Marcus Hook
- marsh deposits
- Marshalltown Formation
- Merchantville Formation
- Metapyroxenite and metagabbro (undifferentiated)
- Middletown
- Mill Creek Metagabbro
- Mount Laurel Formation
- Navesink Formation
- New Castle County
- Newark
- Odessa
- Old College Formation
- Pegmatite
- Perkins Run Gabbronorite Suite
- Potomac Formation
- Quantum GIS
- Rockford Park Gneiss
- rocks
- Scotts Corners Formation
- Serpentinite
- Setters Formation
- Shark River Formation
- surficial geology
- swamp deposits
- undrained depression deposits
- Vincentown Formation
- WFS Feature Service
- Wilmington
- Wilmington Complex
- Wissahickon Formation
- WMS Map Service
- Shapefile



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