Moscow Formation
16-625: Ludlowville Formation Skaneatales Formation Marcellus Formation The Hamilton Group is a Devonian -age geological group which is located in the Appalachian region of the United States . It is present in New York , Pennsylvania , Maryland , Ohio , West Virginia , northwestern Virginia and Ontario, Canada , and is mainly composed of marine shale with some sandstone . There are two main formations encompassed by
32-708: A specific stratigraphic formation in New York state is a stub . You can help Misplaced Pages by expanding it . Tioga Bentonites The Tioga Bentonites are a series of ash bed layers occurring in three Sedimentary basins in the eastern and midwestern United States. The primary basin they are found in is the Appalachian Basin , as well as the Illinois Basin and the Michigan Basin . Due to an unconformity these ash beds are not present in
48-400: Is a good source of road material, riprap and building stone, that is used locally for shale aggregate and common fill. Loyalsburg Formation 40°44′05″N 77°46′42″W / 40.73472°N 77.77833°W / 40.73472; -77.77833 Ludlowville Formation The Ludlowville Formation is a geologic formation in New York , Ohio and Pennsylvania. It dates to
64-625: Is one of the fossils the Owasco is noted for. The Jaycox Formation is a geologic formation in New York. It preserves fossils dating back to the Devonian period. The basial Jaycox contains the Hills Gulch bed, a fossiliferous bed with corals and shells, as well as megaburrows at its basial contact. The Hills Gulch is a calcareous siltstone. The Centerfield Limestone is a geologic formation in New York , and Pennsylvania . It dates back to
80-960: The Brallier Formation (formerly Woodmont Shale, dark laminated shale) at its southern extent. Further north, it is overlain by the Tully Limestone , though some consider the Tully Limestone a subunit of the Mahantango Formation. The Tully Limestone is succeeded by the dark laminated Harrell Shale . In 2012, Read and Erikson reported the group as dating from the Eifelian to Famennian in Virginia. Source: Tropidoleptus carinatus Nucfeospira concinna Mucrospirifer Athyris Pleurodictyum americanum Orthonota undulate Dipleura The Hamilton
96-460: The Devonian period . The Owasco is a thin distinct silty unit. It has sharp distinct boundaries at its top and base. It is flaggy, locally fossiliferous and is displays cross bedding in some locations. The upper contact maybe a diastem , rather than an erosional disconformity. This unit is fairly thin only 1-2' thick in outcrops. It thickens westward. The brachiopod AIlanella tullius
112-685: The Devonian period . It is the lowest member of the Ludlowville Formation and it overlies the Skaneateles Formation . The Peppermill Gulf bed is included within the Centerfield Lime. The unit was named by Smith (1930) This Limestone unit contains fossils of crinoids , rugosa , bivalvia , trilobites and brachiopods. This unit also contains several corals including; Eridophyllum and Heliophyllum hali. Loyalsburg Formation This article about
128-646: The Marcellus Shale , a fissile gray-black to black, thinly laminated, pyritic , carbonaceous thin shale with sparse marine fauna and siderite concretions. The total thickness of the Hamilton Group in Pennsylvania runs about 970 feet. In New York State, it thickens from 250 feet near Lake Erie to over 2,500 feet in Ulster and Greene counties. Depths ranging from outcrops to 8,000 feet below
144-917: The Romney Formation . Relative age dating of the Hamilton places it in the middle and lower Devonian period. In Maryland, it rests conformably atop the Tioga Metabentonite, a thin layer of laminated shale lying over the Needmore Shale . In other regions, the Needmore Shale is replaced by laterally equivalent units such as limestone and shale of the Onondaga Formation , or chert of the Huntersville Chert . The Hamilton Group lies conformably below
160-522: The Hamilton Group consists of the Mahantango Formation , a gray, dark gray, brown, and olive laminated shale; siltstone; and very fine-grained sandstone or claystone containing marine fossils. The uppermost clay layers of the Mahantango Formation are particularly rich in fossils. In New York, central and eastern Pennsylvania the upper sections contain several thick grey shale formations, occasionally marked with limestone stringer. It overlies
176-641: The Hamilton Group formations are, in ascending order, Bell , Rockport Quarry , Arkona , Hungry Hollow , Widder , and Ipperwash ; the Kettle Point Formation of the late Devonian lies unconformably above. The Mahantango Formation includes these members in descending order: Sherman Ridge, Montebello sandstone, Fisher Ridge, Dalmatia, and Turkey Ridge. In south-central Pennsylvania, it includes Clearville, Frame, Chaneysville, and Gander Run Members. Its thickness in Maryland ranges from 600 feet in
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#1732793698995192-846: The Tioga Middle Coarse Zone (MCZ) is located in the Onondaga Group deposited 391.4 million years ago. Finally Tioga A-G K-bentonites are located in the Onodaga Group and the Union Springs Member of the Marcellus Formation deposited 390.0 million years ago. The volcanic ash was deposited in sea water. After sedimentation covered these beds the ash was slowly converted to a meta- Bentonite called Illite . These layers are important because they allow very precise dating of
208-485: The group: the Mahantango Formation and the Marcellus Shale . In southwestern Virginia , where the two sub-units are not easily distinguishable, the Hamilton Group is broadly equivalent to the Millboro Shale or Millboro Formation . The group is named for the village of Hamilton, New York . These rocks are the oldest strata of the Devonian gas shale sequence. In western Pennsylvania, Ohio and West Virginia
224-593: The southern Appalachians. There are 7–15 layers of ash depending on the location covering ~30 million years. These numerous layer are broken down into 4 clusters. The Bald Hill K-bentonites are located in the Kalkberg Formation or New Scotland Formation were deposited 417.6 million years ago. The Sprout Brook K-bentonites are located in the Esopus Formation or Needmore Shale deposited 408.3 million years ago. One cluster called
240-542: The surface of Sullivan County , in the southeastern part of New York state. In the interior lowlands of New York and north eastern and north central Pennsylvania, the Hamilton Group contains the Marcellus , Skaneateles , Ludlowville , and Moscow Formations, in ascending order, with the Tully Limestone above. These units are divided by the Stafford , Centerfield , and Tichenor limestones. In Ontario , Canada,
256-448: The west, increasing to 1,200 feet in the east, and approximately 1000 feet thick in central Pennsylvania. The Marcellus Formation contains a local limestones Purcell Member and Cherry Valley as well as Tioga Bentonites at the base in central and eastern Pennsylvania. Its thickness in Maryland ranges from 250 feet in east, increasing to 500 feet in the west. The Hamilton Group, Tioga Bentonites , and Needmore Shale were formerly called
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