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Douglas W. Rankin

Publications and source records attributed to Douglas W. Rankin.

15 recordsLinked to original sources
USGS2018

Bedrock geologic map of the Littleton and Lower Waterford quadrangles, Essex and Caledonia Counties, Vermont, and Grafton County, New Hampshire

The bedrock geologic map of the Littleton and Lower Waterford quadrangles covers an area of approximately 107 square miles (277 square kilometers) north and south of the Connecticut River in east-central Vermont and adjacent New Hampshire. This map was created as part of a larger effort to produce a new bedrock geologic map of Vermont through the collection of field data at a scale of 1:24,000. A large part of the map area consists of the Bronson Hill anticlinorium, a post-Early Devonian structure that is cored by metamorphosed Cambrian to Devonian sedimentary, volcanic, and plutonic rocks. The northwestern part of the map is divided by the Monroe fault which separates Early Devonian rocks of the Connecticut Valley-Gaspé trough from rocks of the Bronson Hill anticlinorium. The Bronson Hill anticlinorium is the apex of the Middle Ordovician to earliest-Silurian Bronson Hill magmatic arc that contains the Ammonoosuc Volcanics, Partridge Formation, and Oliverian Plutonic suite, and extends from Maine, down the eastern side of the Connecticut River in New Hampshire, to Long Island Sound. The deformed and partially eroded arc is locally overlain by a relatively thin Silurian section of metasedimentary rocks (Clough Quartzite and Fitch Formation) that thickens to the east. The Silurian section near Littleton is disconformably overlain by a thicker, Lower Devonian section that includes mostly metasedimentary rocks and minor metavolcanic rocks of the Littleton Formation. The Bronson Hill anticlinorium is bisected by a series of northeast-southwest trending Mesozoic normal faults. Primarily among them is the steeply northwest-dipping Ammonoosuc fault that divides older and younger units (upper and lower sections) of the Ammonoosuc Volcanics. The Ammonoosuc Volcanics are lithologically complex and predominantly include interlayered and interfingered rhyolitic to basaltic volcanic and volcaniclastic rocks, as well as lesser amounts of metamorphic and metasedimentary rocks. The Ammonoosuc Volcanics overlies the Albee Formation that consists of interlayered feldspathic sandstone, siltstone, pelite, and slate. During the Late Ordovician, a series of arc-related plutons intruded the Ammonoosuc Volcanics, including the Whitefield pluton to the east, the Scrag granite of Billing (1937) in the far southeastern corner of the map, the Highlandcroft Granodiorite just to the west of the Ammonoosuc fault, and the Joslin Turn tonalite (just north of the Connecticut River). To the east of the Monroe fault lies the late Silurian Comerford Intrusive Complex, which consists of metamorphosed gabbro, diorite, tonalite, aplitic tonalite, and crosscutting diabase dikes. Abundant mafic dikes of the Comerford Intrusive Complex intruded the Albee Formation and Ammonoosuc Volcanics well east of the Monroe fault. This report consists of a single geologic map sheet and an online geographic information systems database that includes contacts of bedrock geologic units, faults, outcrops, and structural geologic information.

New Hampshire, Vermont↗
USGS2018

Bedrock geologic map of the Lisbon quadrangle, and parts of the Sugar Hill and East Haverhill quadrangles, Grafton County, New Hampshire

The bedrock geologic map of the Lisbon quadrangle, and parts of the Sugar Hill and East Haverhill quadrangles, Grafton County, New Hampshire, covers an area of approximately 73 square miles (189 square kilometers) in west-central New Hampshire. This map was created as part of a larger effort to produce a new bedrock geologic map of Vermont through the collection of field data at a scale of 1:24,000. A large part of the map area consists of the Bronson Hill anticlinorium, a post-Early Devonian structure that is cored by metamorphosed Cambrian to Devonian sedimentary, volcanic, and plutonic rocks. The Bronson Hill anticlinorium is the apex of the Middle Ordovician to earliest-Silurian Bronson Hill magmatic arc that contains the Ammonoosuc Volcanics, Partridge Formation, and Oliverian Plutonic Suite, and extends from Maine, through western New Hampshire (down the eastern side of the Connecticut River), through southern New England to Long Island Sound. The deformed and partially eroded arc is locally overlain by a relatively thin Silurian section of metasedimentary rocks (Clough Quartzite and Fitch Formation) that thickens to the east. The Silurian section near Littleton is disconformably overlain by a thicker, Lower Devonian section that includes mostly metasedimentary and minor metavolcanic rocks of the Littleton Formation. The Bronson Hill anticlinorium is bisected by a series of northeast-southwest trending Mesozoic normal faults. Primarily among them is the steeply northwest-dipping Ammonoosuc fault that divides older and younger units (lower and upper sections) of the Ammonoosuc Volcanics. The Ammonoosuc Volcanics are lithologically complex and predominantly include interlayered and interfingered rhyolitic to basaltic volcanic and volcaniclastic rocks, as well as lesser amounts of slate, phyllite, ironstone, chert, sandstone, and pelite. The Albee Formation underlies the Ammonoosuc Volcanics and is predominantly composed of interbedded metamorphosed sandstone, siltstone, and phyllite. During the Late Ordovician, a series of arc-related plutons intruded the Ammonoosuc Volcanics including the Moody Ledge pluton and the Scrag granite of Billings (1937). Subsequent plutonism related to the Acadian orogeny occurred after volcanism and deposition resulted in the Littleton Formation during the Late Devonian, including the intrusion of the Haverhill pluton and French Pond Granite found in the southern part of the map. This report consists of a geologic map and an online geographic information systems database that includes contacts of bedrock geologic units, faults, outcrops, and structural geologic information. The geologic map is intended to serve as a foundation for applying geologic information to problems involving land use decisions, groundwater availability and quality, earth resources such as natural aggregate for construction, assessment of natural hazards, and engineering and environmental studies for waste disposal sites and construction projects.

New Hampshire↗
USGS2018

Bedrock geologic map of the Miles Pond and Concord quadrangles, Essex and Caledonia Counties, Vermont, and Grafton County, New Hampshire

The bedrock geologic map of the Miles Pond and Concord quadrangles covers an area of approximately 107 square miles (276 square kilometers) in east-central Vermont and adjacent New Hampshire, north of and along the Connecticut River. This map was created as part of a larger effort to produce a new bedrock geologic map of Vermont through the collection of field data at a scale of 1:24,000. The majority of the map area consists of the Bronson Hill anticlinorium, a post-Early Devonian structure that is cored by metamorphosed Cambrian to Silurian sedimentary, volcanic, and plutonic rocks. A major feature on the map is the Monroe fault, interpreted to be a west-directed, steeply dipping Late Devonian (Acadian) thrust fault. To the west of the Monroe fault, rocks of the Connecticut Valley-Gaspé trough dominate and consist primarily of metamorphosed Silurian and Devonian sedimentary rocks. To the north, the Victory pluton intrudes the Bronson Hill anticlinorium. The Bronson Hill anticlinorium consists of the metamorphosed Albee Formation, the Ammonoosuc Volcanics, the Comerford Intrusive Complex, the Highlandcroft Granodiorite, and the Joselin Turn tonalite. The Albee Formation is an interlayered, feldspathic metasandstone and pelite that is locally sulfidic. Much of the deformed metasandstone is tectonically pinstriped. In places, one can see compositional layering that was transposed by a steeply southeast-dipping foliation. The Ammonoosuc Volcanics are lithologically complex and predominantly include interlayered and interfingered rhyolitic to basaltic volcanic and volcaniclastic rocks, as well as lesser amounts of siltstone, phyllite, graywacke, and grit. The Comerford Intrusive Complex crops out east of the Monroe fault and consists of metamorphosed gabbro, diorite, tonalite, aplitic tonalite, and crosscutting diabase dikes. Abundant mafic dikes from the Comerford Intrusive Complex intruded the Albee Formation and Ammonoosuc Volcanics east of the Monroe fault. The Highlandcroft Granodiorite and Joslin Turn tonalite plutons intruded during the Middle to Late Ordovician. West of the Monroe fault, the Connecticut Valley-Gaspé trough consists of the Silurian and Devonian Waits River and Gile Mountain Formations. The Waits River Formation is a carbonaceous muscovite-biotite-quartz (±garnet) phyllite containing abundant beds of micaceous quartz-rich limestone. The Gile Mountain Formation consists of interlayered metasandstone and graphitic (and commonly sulfidic) slate, along with minor calcareous metasandstone and ironstone. Graded bedding is common in the Gile Mountain Formation. Rocks of the Devonian New Hampshire Plutonic Suite intruded as plutons, dikes, and sills. The largest of these is the Victory pluton, which consists of weakly foliated, biotite granite and granodiorite. The Victory pluton also intruded a large part of the Albee Formation to the north. This report consists of a geologic map and an online geographic information systems database that includes contacts of bedrock geologic units, faults, outcrops, and structural geologic information. The geologic map is intended to serve as a foundation for applying geologic information to problems involving land use decisions, groundwater availability and quality, earth resources such as natural aggregate for construction, assessment of natural hazards, and engineering and environmental studies for waste disposal sites and construction projects.

New Hampshire, Vermont↗
USGS2014

A field trip guidebook to the type localities of Marland Billings' 1935 Paleozoic bedrock stratigraphy near Littleton, New Hampshire

Marland Billings' classic paper published in 1937 in the Geological Society of America Bulletin established a succession of six stratigraphic units in rocks of low metamorphic grade near Littleton, New Hampshire. The two youngest units are fossiliferous in the area, with ages established at the time as “middle” Silurian and Early Devonian. Billings and students mapped the same stratigraphic section in adjacent areas of progressively higher regional metamorphic grade. This work laid the foundation upon which a major part of subsequent work in New England has been directly or indirectly built. This guidebook was written for a field trip held in March 2013 to visit roadcuts that are as close as possible in March to the type localities or areas of Billings’ six-fold stratigraphic succession. Ten stops are in rocks of chlorite grade of Acadian(?) metamorphism; the final stop visits amphibolite of the Ammonoosuc Volcanics. Fieldwork by the authors over the past 20 years confirms Billings’ broad conclusions.

New Hampshire↗
USGS2012

Igneous activity, metamorphism, and deformation in the Mount Rogers area of SW Virginia and NW North Carolina: A geologic record of Precambrian tectonic evolution of the southern Blue Ridge Province

Mesoproterozoic basement in the vicinity of Mount Rogers is characterized by considerable lithologic variability, including major map units composed of gneiss, amphibolite, migmatite, meta-quartz monzodiorite and various types of granitoid. SHRIMP U-Pb geochronology and field mapping indicate that basement units define four types of occurrences, including (1) xenoliths of ca. 1.33 to ≥1.18 Ga age, (2) an early magmatic suite including meta-granitoids of ca. 1185–1140 Ma age that enclose or locally intrude the xenoliths, (3) metasedimentary rocks represented by layered granofels and biotite schist whose protoliths were likely deposited on the older meta-granitoids, and (4) a late magmatic suite composed of younger, ca. 1075–1030 Ma intrusive rocks of variable chemical composition that intruded the older rocks. The magmatic protolith of granofels constituting part of a layered, map-scale xenolith crystallized at ca. 1327 Ma, indicating that the lithology represents the oldest, intact crust presently recognized in the southern Appalachians. SHRIMP U-Pb data indicate that periods of regional Mesoproterozoic metamorphism occurred at 1170–1140 and 1070–1020 Ma. The near synchroneity in timing of regional metamorphism and magmatism suggests that magmas were emplaced into crust that was likely at near-solidus temperatures and that melts might have contributed to the regional heat budget. Much of the area is cut by numerous, generally east- to northeast-striking Paleozoic fault zones characterized by variable degrees of ductile deformation and recrystallization. These high-strain fault zones dismember the terrane, resulting in juxtaposition of units and transformation of basement lithologies to quartz- and mica-rich tectonites with protomylonitic and mylonitic textures. Mineral assemblages developed within such zones indicate that deformation and recrystallization likely occurred at greenschist-facies conditions at ca. 340 Ma.

North Carolina, Virginia↗
USGS2012

Reevaluation of the Piermont-Frontenac allochthon in the Upper Connecticut Valley: Restoration of a coherent Boundary Mountains–Bronson Hill stratigraphic sequence

The regional extent and mode and time of emplacement of the Piermont-Frontenac allochthon in the Boundary Mountains–Bronson Hill anticlinorium of the Upper Connecticut Valley, New Hampshire–Vermont, are controversial. Moench and coworkers beginning in the 1980s proposed that much of the autochthonous pre–Middle Ordovician section of the anticlinorium was a large allochthon of Silurian to Early Devonian rocks correlated to those near Rangeley, Maine. This ∼200-km-long allochthon was postulated to have been transported westward in the latest Silurian to Early Devonian as a soft-sediment gravity slide on a hypothesized Foster Hill fault. New mapping and U-Pb geochronology do not support this interpretation. The undisputed Rangeley sequence in the Bean Brook slice is different from the disputed sequence in the proposed larger Piermont-Frontenac allochthon, and field evidence for the Foster Hill fault is lacking. At the type locality on Foster Hill, the postulated “fault” is a stratigraphic contact within the Ordovician Ammonoosuc Volcanics. The proposed Foster Hill fault would place the Piermont-Frontenac allochthon over the inverted limb of the Cornish(?) nappe, which includes the Emsian Littleton Formation, thus limiting the alleged submarine slide to post-Emsian time. Mafic dikes of the 419 Ma Comerford Intrusive Complex intrude previously folded strata attributed to the larger Piermont-Frontenac allochthon as well as the autochthonous Albee Formation and Ammonoosuc Volcanics. The Lost Nation pluton intruded and produced hornfels in previously deformed Albee strata. Zircons from an apophysis of the pluton in the hornfels have a thermal ionization mass spectrometry 207 Pb/ 206 Pb age of 444.1 ± 2.1 Ma. Tonalite near Bath, New Hampshire, has a zircon sensitive high-resolution ion microprobe 206 Pb/ 238 U age of 492.5 ± 7.8 Ma. The tonalite intrudes the Albee Formation, formerly interpreted as the Silurian Perry Mountain Formation of the proposed allochthon. Collectively, these features indicate that the large Piermont-Frontenac allochthon gravity slide of Silurian-Devonian strata, as previously proposed, cannot exist. Allochthonous rocks are restricted to a 25 km 2 klippe, the Bean Brook slice, emplaced by hard-rock thrusting in the post-Emsian Devonian. The Albee Formation, the oldest unit in the study area, is older than the Late Cambrian tonalite at Bath. The correlation and apparent continuity along strike to the northeast of the Albee Formation with the Dead River Formation suggest that the Albee Formation, like the Dead River Formation, is of Ganderian affinity and that the Bronson Hill magmatic arc in the Upper Connecticut Valley was built on Ganderian crust. The Dead River Formation is unconformably overlain by Middle and Upper Ordovician volcanic units; the unconformity is attributed to the pre-Arenig Penobscottian orogeny. Some of the pre-Silurian deformation in the Upper Connecticut Valley may be Penobscottian rather than Taconian. New stratigraphic units defined herein include the pelitic Scarritt Member of the Albee Formation, the Ordovician Washburn Brook Formation consisting of synsedimentary breccia and coticule, chert, and ironstone, and the Devonian–Silurian Sawyer Mountain Formation, probably correlative with the Frontenac Formation. The Partridge Formation is partially coeval with the Ammonoosuc Volcanics.

New Hampshire;Vermont↗
USGS2002

Geology of St. John, U.S. Virgin Islands

The rocks of St. John, which is located near the eastern end of the Greater Antilles and near the northeastern corner of the Caribbean plate, consist of Cretaceous basalt, andesite, keratophyre, their volcaniclastic and hypabyssal intrusive equivalents, and minor calcareous rocks and chert. These rocks were intruded by Tertiary mafic dikes and tonalitic plutons. The oldest rocks formed in an extensional oceanic environment characterized by abundant keratophyre and sheeted dikes. Subduction-related volcanism of the east-west-trending marine Greater Antilles volcanic arc began on St. John near the transition between the Early and Late Cretaceous. South-directed compression, probably caused by the initial collision between the Greater Antilles arc of the Caribbean plate and the Bahama platform of the North American plate, deformed the Cretaceous strata into east-west-trending folds with axial-plane cleavage. Late Eocene tonalitic intrusions, part of the Greater Antilles arc magmatism, produced a contact aureole that is as much as two kilometers wide and that partly annealed the axial-plane cleavage. East-west compression, possibly related to the relative eastward transport of the Caribbean plate in response to the beginning of spreading at the Cayman Trough, produced long-wavelength, low-amplitude folds whose axes plunge gently north and warp the earlier folds. A broad north-plunging syncline-anticline pair occupies most of St. John. The last tectonic event affecting St. John is recorded by a series of post-late Eocene sinistral strike-slip faults related to the early stages of spreading at the Cayman Trough spreading center and sinistral strike-slip accommodation near the northern border of the Caribbean plate. Central St. John is occupied by a rhomb horst bounded by two of these sinistral faults. Unlike other parts of the Greater Antilles, evidence for recent tectonic movement has not been observed on St. John.

Professional Paper↗
USGS1994

Preliminary bedrock geologic map of parts of the Lower Waterford, Concord, Littleton, and Miles Pond 7 1/2-minute quadrangles, Vermont and New Hampshire

The map area, in east-central Vermont and adjacent New Hampshire, consists of parts of the Lower Waterford, Concord, Littleton and Miles Pond 7 1/2-minute quadrangles (Fig. 1) that together constitute the Littleton 15-minute quadrangle. The mapping is part of the effort to produce a new bedrock geologic map of Vermont through the collection of field data at a scale of 1:24,000. The focus of my part of the project is to map and interpret the "New Hampshire sequence" rocks (White and Jahns, 1950) that crop out in Vermont and their relationship to those of the "Vermont sequence", or the Connecticut Valley trough, west of the Monroe line, here a fault (Hatch, 1988a). The work is a continuation of mapping just initiated by N.L. Hatch, Jr., prior to his death in 1991. This particular map area was chosen as the place to initiate this study because it includes one of the largest areas of the New Hampshire sequence in Vermont, because it is adjacent to and on strike with the Littleton-Moosilauke area in New Hampshire that includes the type area of most of the units of the New Hampshire sequence (Billings, 1935, 1937), and because the Connecticut River here runs roughly east to west across the regional strike and might provide a good stratigraphic section across the rocks under study. The mapping showed that no bedrock is exposed along either bank of the Connecticut River across most of the area, but there are excellent exposures in the spillways of two large dams, Moore Dam on the east and Comerford Dam on the west (about 100 m west of the Lower Waterford quadrangle), along Interstate Highway 93 (1-93), and adequate exposures in the hills above the river. My mapping was mostly in the Vermont parts of the Littleton 15-minute quadrangle but included some work in the Barnett 7 1/2 x 15-minute quadrangle to the west and a zone along the New Hampshire side of the Connecticut River that included Albee Hill, Partridge Lake, Highland Croft farm, the former Fitch farm, and the outskirts of Littleton. The Vermont mapping is thus tied to the classic Littleton-Moosilauke area of Billings (1937) and the fossiliferous Fitch and Littleton Formations in their type areas.

New Hampshire, Vermont↗
USGS1991

E-4 Central Kentucky to the Carolina Trough

E-4 is one of eight Geodynamics transects that cross the Atlantic margin of North America between Georgia and Newfoundland. Five of the transects are in the United States and three are in Canada. Transect E-4, which is 110 km wide and more than 1,100 km long, extends from the stable North American craton just west of the Grenville front near Lexington, Kentucky southeastward across Cape Fear, North Carolina, on the Atlantic coast to oceanic crust east of the Blake Spur magnetic anomaly. Like all of the other U.S. Atlantic coast transects, it crosses Cambrian and Jurassic continental margins of North America as well as the Appalachian orogen. The display, based upon published information, portrays the geology, tectonic style and geophysical expression of this segment of the eastern North American continental margin and interprets its Phanerozoic history. The Decade of North American Geology 1983 geologic time scale (Palmer, 1983) is used throughout the display and text.

Book↗
USGS1977

Studies related to the Charleston, South Carolina, earthquake of 1886: A preliminary report

PART A: The seismic history of the southeastern United States is dominated by the 1886 earthquake near Charleston, S.C. An understanding of the specific source and the uniqueness of the neotectonic setting of this large earthquake is essential in order to properly assess seismic hazards in the southeastern United States. Such knowledge will also contribute to the fundamental understanding of intraplate earthquakes and will aid indirectly in deciphering the evolution of Atlantic-type continental margins. The 15 chapters in this volume report on the first stage of an ongoing multidisciplinary study of the Charleston earthquake of 1886. The Modified Mercalli intensity for the 1886 earthquake was X in the meizoseismal area, an elliptical area 35 by 50 km, the center of which was Middleton Place. Seismic activity is continuing today in the Middleton Place-Summerville area at a higher level than prior to 1886. The present seismicity is originating at depths of 1 to 8 km, mostly in the crystalline basement beneath sedimentary rocks of the Coastal Plain. The crystalline basement beneath the Charleston-Summerville area is not simply a seaward extension of crystalline rocks of the Appalachian orogen that are exposed in the Piedmont to the northwest, but has a distinctive magnetic signature that does not reflect Appalachian orogenic trends. The area underlain by this distinctive geophysical basement, the Charleston block, may represent a broad zone of Triassic and (or) Jurassic crustal extension formed during the early stages of the opening of the Atlantic Ocean. The Charleston block is characterized in part by prominent, roughly circular magnetic and gravity highs that are thought to reflect maflc or ultramafic plutons. A continuously cored borehole put down over the shallowest (about 1.5 km deep) of these magnetic anomalies on the edge of the meizoseismal area bottomed at 792 m in amygdaloidal basalt. Although the K-Ar ages of about 100 m.y. for the basalt are consistent with the Late Cretaceous (Cenomanian) age of the overlying Cape Fear Formation, this must be a minimum age as a result of chemical alteration. The interpreted magmatic composition of the basalt most closely resembles the high-Ti quartz-normative tholeiites of Late Triassic and Early Jurassic age from eastern North America; age of the basalt is probably similar. Various geophysical surveys suggest that Coastal Plain sedimentary rocks do not simply dip homoclinally to the southeast on a gently dipping basement surface but are disturbed by structures not yet clearly deciphered. The present stress regime of the Charleston-Summerville area appears to be one of NE-SW. compression rather than of extension as it presumably was in the Mesozoic. The present stress regime seems similar to that of much of the eastern United States. Comparison of several seismic source areas in eastern North America shows that epicenters are typically near the periphery of positive gravity features interpreted to represent mafic or ultramafic bodies. Earthquakes may be caused by the concentration of regional stress around the peripheries of these inhomogeneities in an otherwise more homogeneous plate. Whether the inhomogeneities are more or less rigid than the. surrounding material is uncertain. PART B: In 1889, C. E. Dutton published all his basic intensity data for the 1886 Charleston, S.C., shock but did not list what intensity values he assigned to each report, nor did he show the distribution of the locations of these data reports on his isoseismal map. The writer and two other seismologists have each independently evaluated Dutton's 1,300 intensity reports (at least two of the. three interpreters agreed on intensity values for 90 percent of the reports), and the consensus values were plotted and contoured. One map was prepared on which contours emphasized the broad regional pattern of effects (with results similar to Dutton's) ; another map was contoured to depict the more

South Carolina↗