Chronostratigraphic relations of neogene formations of the Great Hungarian Plain based on interpretation of seismic and paleomagnetic data
No abstract available.
Great Hungarian Plain↗
Geology topics
Robert E. Mattick
Publications and source records attributed to Robert E. Mattick.
Structure, stratigraphy, and petroleum geology of the Little Plain basin, northwestern Hungary
The basement of the Little Plain (Kisalfold) basin is composed of two parts: an eastern part comprised of folded and overthrusted Triassic and Paleozoic rocks of the Pelso block (Transdanubian Central Range) compressed in the Early Cretaceous, and a western part consisting of stacked nappes of the Austroalpine zone of Paleozoic rocks, significantly metamorphosed during Cretaceous and later compression, overriding Jurassic oceanic rift-zone rocks of the Penninic zone. The evolution of the basin began in the late Karpatian-early Badenian (middle Miocene) when the eastern part of the basin began to open along conjugate sets of northeast- and northwest-trending normal faults. Neogene rocks in the study area, on the average, contain less than 0.5 wt. % total organic carbon (TOC) and, therefore, are not considered effective source rocks. Locally, however, where TOC values are as high as 3 wt. %, significant amounts of gas may have been generated and expelled. Although potential stratigraphic traps are numerous in the Neogene section, these potential traps must be downgraded because of the small amount of hydrocarbons discovered in structural traps to date. With the exception of the Cretaceous, the Mesozoic section has not been actively explored. Large anticlinal and overthrust structures involving pre-Cretaceous strata remain undrilled.
Little Plain basin↗
Structural framework, stratigraphy, and petroleum geology of the area of oil and gas lease Sale No. 49 on the U.S. Atlantic continental shelf and slope
On September 23, 1977, the U.S. Department of the Interior announced the tentative selection of 136 tracts for Sale No. 49 of oil and gas leases in the Baltimore Canyon Trough on the U.S. Atlantic Continental Shelf and Slope. This report summarizes the geology and petroleum potential of the area. The Baltimore Canyon Trough is an elongate, seaward-opening sedimentary basin filled by as much as 14 km of Mesozoic and Cenozoic sedimentary rocks. The basin first formed under the New Jersey shelf and gradually spread west and south as the area subsided after the rifting that formed the Atlantic basin. Rocks of the Triassic and Jurassic Systems together are more than 8 km thick in a depocenter areally restricted to the northern part of the trough. Basal Jurassic rocks are apparently nonmarine sedimentary rocks bedded with evaporite deposits. Direct evidence that some salt is in the basal Jurassic section comes from the Houston Oil and Minerals 676-1 well, which penetrated salt at a depth of about 3.8 km. During the Middle and Late Jurassic, more open marine conditions prevailed than in the Early Jurassic, and carbonate banks and reefs formed discontinuously along the seaward side of the shelf. Sand flats likely occupied the central part of the shelf, and these probably graded shoreward into nonmarine red beds that accumulated in a bordering coastal plain. Thick nonmarine sands and silty shales of Late Jurassic age were deposited in what is now the nearshore and midshelf area. These sedimentary rocks probably grade into thick marine carbonate rocks near the present shelf edge. During the Cretaceous, less sediment accumulated (about 4 km) than during the Jurassic, and most was deposited during Early Cretaceous time. The Cretaceous units show two main trends through time-a diminishing rate of sediment accumulation and an increase in marine character of sediments. During the Middle and Late Cretaceous, calcareous sand and mud filled the basin, buried the shelf-edge reefs and later spilled across the reefs into the oceanic basin as worldwide sea level reached a maximum. Cenozoic deposits are spread over the present shelf and adjacent Coastal Plain in overlapping sheets of marine and nonmarine sediment. The maximum thickness (1.5 km) is along the outer part of the present shelf. Major tectonic deformation in the Baltimore Canyon Trough area appears to have terminated near the end of the Early Cretaceous, when at least one large mafic intrusion (Great Stone dome) was emplaced. Upper Cretaceous sedimentary rocks are arched above older uplifted fault blocks near the shelf edge; this arching may be the result of draping due to differential compaction or, perhaps, minor movement of the fault blocks during Late Cretaceous time. The dominance of terrestrial over marine-derived organic matter in sediment samples from the COST No. B-2 well indicates that economic amounts of liquid petroleum hydrocarbons were probably not generated in the area but suggests a high potential for generation of wet or dry gas. Supporting evidence for the presence of natural-gas deposits on the slope comes from AMCOR 6021, the upper 305 m of which penetrated sediments that contained methane, ethane, and propane. Texaco, Inc., has announced that its 598-1 well yielded nearly 479,000 m s of natural gas per day from two zones during early testing. Further indication of possible gas deposits comes from analyzing the amplitude (bright spots) of seismic data. Geochemical studies of the COST No. B-2 well have shown that the shelf area of the Baltimore Canyon Trough has a relatively low geothermal gradient today and that it apparently has had a gradient as low or even lower throughout the Cretaceous to Holocene. A controversy exists concerning the maturity of the basal sediments penetrated by the COST No. B-2 well. Although significant amounts of gaseous hydrocarbons may have been generated, large amounts of liquid petroleum hydrocarbons probably hav
Circular↗
Summary report of the sediments, structural framework, petroleum potential, and environmental conditions of the United States Mid-Atlantic continental margin in area of proposed Oil & Gas Lease Sale No. 59
This report has been compiled to update and summarize the geological information concerning the area of the Atlantic continental margin off the U.S. Mid-Atlantic proposed for Oil and Gas Lease Sale No. 59 (fig. 1). The region of interest lies between 35° and 41° N and 70.5° and 76° W. The north-south dimension is about 660 km (356 nautical miles, 410 statute miles) and the maximum east-west dimension is approximately 250 km (135 nautical miles, 155 statute miles). The area is centered toward the outer Continental Shelf off Delaware and contains more than 154,000 km2 (38,000,000 acres) off the coasts of North Carolina, Virginia, Maryland, Delaware, New Jersey and New York. Water depths within the region range from 20 to slightly more than 4,000 m (fig. 1). This report begins with a discussion of the regional geology and geophysics, followed by a description of the oil and gas potential and potential environmental hazards.
Delaware, Maryland, New Jersey, New York, North Ca↗
Gravity, magnetic, and seismic studies of the Silver Cliff and Rosita Hills volcanic area, Colorado
No abstract available.
Colorado↗
Multichannel seismic depth sections and interval velocities over outer continental shelf and upper continental slope between Cape Hatteras and Cape Cod: Rifted margins
Six computer-generated seismic depth sections over the outer continental shelf and upper slope reveal that subhorizontal Lower Cretaceous reflectors continue 20 to 30 km seaward of the present shelf edge. Extensive erosion on the continental slope has occurred primarily during the Tertiary, causing major unconformities and retreat of the shelf edge to its present position. The precise age and number of erosional events is not established, but at least one major erosional event is thought to be Oligocene and related to a marine regression in response to a worldwide eustatic lowering of sea level. Velocities derived from the multichannel data reveal distinctive ranges and lateral trends as functions of sediment age, depth of burial, and distance from the coastline. Seismic units beneath the shelf and slope of inferred Tertiary age range from 1.7 to 2.7 km/sec, increasing with age and depth of burial. Units interpreted as Upper Cretaceous rocks beneath the shelf range from 2.3 to 3.6 km/sec and show a distinct lateral increase across the shelf followed by a decrease beneath the present continental slope. Inferred Lower Cretaceous and Upper Jurassic rocks beneath the shelf increase from 3.7 to 4.8 km/sec from nearshore to offshore and indicate a change in facies from clastic units below the inner shelf to carbonate units beneath the outer shelf and upper continental slope. Both reflection and refraction data suggest that thin, high-velocity limestone units (5.0 km/sec) are present within the Lower Cretaceous and Upper Jurassic units beneath the outermost shelf edge, but that these change lithology or pinch out before reaching the middle shelf. Although lateral changes in velocity across the shelf and local velocity inversions appear, the interval velocities along the length of the margin show excellent continuity between Cape Hatteras and Cape Cod. The high-velocity horizons within the Lower Cretaceous and Upper Jurassic shelf-edge complex indicate the presence of a carbonate bank or reef. The continental shelf off New Jersey is underlain by a trough approximately 150 km wide with up to 12 km of sedimentary fill. The oceanic basement beneath the upper continental rise is usually at a depth of 10 to 11 km and is overlain by 6 to 8 km of sediments. The rise sediment trough is separated from the shelf trough by an acoustic basement ridge 25 to 75 km wide where penetration never exceeds 6 km beneath sea level, although faulting and carbonate bank or reef complexes frequently limit penetration to 3 to 4 km in this zone. The acoustic basement ridge coincides with the East Coast Magnetic Anomaly and is interpreted as thick oceanic crust formed during the initial phase of seafloor spreading between North America and Africa. Rapid differential subsidence occurred on opposite sides of the basement ridge during the Jurassic and Early Cretaceous. Differential subsidence beneath the shelf also occurred along the margins, with narrower and shallower shelf troughs occurring off platform areas such as Cape Cod and Cape Hatteras.
Cape Cod, Cape Hatteras↗
Regional geologic framework off northeastern United States
Six multichannel seismic-reflection profiles taken across the Atlantic continental margin off the northeastern United States show an excess of 14 km of presumed Mesozoic and younger sedimentary rocks in the Baltimore Canyon trough and 8 km in the Georges Bank basin. Beneath the continental rise, the sedimentary prism thickness exceeds 7 km south of New Jersey and Maryland, and it is 4.5 km thick south of Georges Bank. Stratigraphically, the continental slope–outer edge of the continental shelf is a transition zone of high-velocity sedimentary rock, probably carbonate, that covers deeply subsided basement. Acoustically, the sedimentary sequence beneath the shelf is divided into three units which are correlated speculatively with the Cenozoic, the Cretaceous, and the Jurassic-Triassic sections. These units thicken offshore, and some have increased seismic velocities farther offshore. The uppermost unit thickens from a fraction of a kilometer to slightly more than a kilometer in a seaward direction, and velocity values range from 1.7 to 2.2 km/sec. The middle unit thickens from a fraction of a kilometer to as much as 5 km (northern Baltimore Canyon trough), and seismic velocity ranges from 2.2 to 5.4 km/sec. The lowest unit thickens to a maximum of 9 km (northern Baltimore Canyon), and velocities span the 3.9 to 5.9-km/sec interval. The spatial separation of magnetic and gravity anomalies on line 2 (New Jersey) suggests that in the Baltimore Canyon region the magnetic-slope anomaly is due to edge effects and that the previously reported free-air and isostatic gravity anomalies over the outer shelf may be due in part to a lateral increase in sediment density (velocity) near the shelf edge. The East Coast magnetic anomaly and the free-air gravity high both coincide over the outer shelf edge on line 1 (Georges Bank) but are offset by 20 km from the ridge on the reflection profile. Because the magnetic-slope-anomaly wavelength is nearly 50 km across, a deep source is likely. In part, the positive free-air gravity anomaly likewise may represent the significant lateral density increase within the sedimentary section toward the outer edge of the shelf.
American Association of Petroleum Geologists Bulle↗
Summary report of the sediments, structural framework, petroleum potential, environmental conditions, and operational considerations of the United States Mid-Atlantic Continental Shelf
Explore the source record for details and available documents.
Open-File Report↗
Structure of continental margin off Mid-Atlantic states (Baltimore Canyon Trough)
Increasing interest in the Atlantic continental margin as a future petroleum province has resulted in several recent papers (Emmerich, 1974; Burk and Drake, 1974) that attempt to summarize the structure and stratigraphic framework of this area. Most papers tend to portray the margin as a wedge of Mesozoic and Cenozoic sediment that thins at the edge of the shelf over a "basement ridge" and then thickens again under the continental rise. Off the northeastern United States, the sediment wedge under the shelf attains a thickness of 8-11 km in the Georges Bank basin (Schultz and Glover, 1974; Mattick and others, 1974; Sheridan, 1974b; Behrendt and others, 1974) and 12 km in thickness in the Baltimore Canyon trough off the middle Atlantic states of Delaware, Maryland, Virginia and New Jersey (fig. 1). Seaward of the continental shelf and its sediment prism, Emery and Uchupi (1972, figs. 133-135) infer slump deposits (eroded in some areas) covering a buried ridge thought to extend from the Laurentian Channel to Cape Hatteras, where it splits in two. The lower slope and continental rise are inferred by Drake and later investigators to be a thick prism of deep sea sediment (turbidites, hemipelagic clays, slump deposits) overlying oceanic basement in a welt that parallels the continental edge and reaches a maximum thickness of 6 km (Emery and Uchupi, 1972, fig. 188). Our purpose is to present the results of a geophysical survey across the margin seaward of the middle Atlantic states that comments on the structural - stratigraphic framework of the margin.
Open-File Report↗
Atlantic OCS resource and leasing potential
Thick marine sedimentary sections and geologic structures favorable for the accumulation of petroleum are indicated in Georges Bank basin, the Baltimore Canyon trough, and the Southeast Georgia embayment. Undiscovered recoverable resources of petroleum on the Atlantic OCS are estimated to be 10 billion to 20 billion barrels of oil and 55 trillion to 110 trillion cubic feet of gas. Such estimates carry a high degree of uncertainty. Preliminary results suggest that the most favorable areas for leasing are under the deeper waters of the shelf.
Atlantic OCS, Baltimore Canyon trough, Georges Ban↗
Seismic-reflection records from a survey at the Rocky Mountain Arsenal near Denver, Colorado
During July 1966, after competitive bidding, a contract was awarded by the U.S. Geological Survey to GeoData Corporation and Geo Prospectors, Inc., both of Tulsa, Oklahoma, for 18 miles of continuous seismic-reflection profiling in the vicinity of a deep injection disposal well (IDW) at the Rocky Mountain Arsenal near Denver, Colorado. The purpose of this survey was to determine if structure exists in the 12,000-ft sedimentary section or in the Precambrian basement that might be related to the series of earthquakes that occurred in the area starting in the spring of 1962. A paper on the seismic-reflection profiling by Ben R. Rummerfield, A. Peter Olson, and D. B. Hoover (1968) reported the major conclusions of the survey.
Colorado↗
A geophysical study of North Park and the surrounding ranges, Colorado
A geophysical study in the North Park basin and surrounding mountains, Colorado illustrates the structural relationship of various sedimentary, metamorphic, and igneous rock units. Bouguer anomalies from 1330 gravity stations range from −210 mgal over Precambrian metamorphic rocks in the mountains to −260 mgal in the Walden syncline and —280 mgal in the North Park syncline. Steep gradients delineate a fault which strikes west-northwest along the north flank of the North Park syncline. Two models fitted to the gravity data show 1 to 2 km relief on this steeply dipping fault. Density contrasts between Precambrian metamorphic and igneous rocks produce anomalies of as much as 25-mgal amplitudes in the Park and Medicine Bow Ranges. A 30-km-long seismic refraction profile, parallel to the most negative Bouguer anomaly values in the North Park basin, shows velocities increasing from 2.5 to 3.4 km/sec within Tertiary rocks at depths ranging from 1.2 to 2.0 km. Mesozoic sedimentary rocks have a velocity of 4.0 to 4.5 km/sec, a very high velocity in view of the predominance of Upper Cretaceous rocks. Precambrian basement with a velocity of 6.25 km/sec underlies the profile at depths ranging from 3.5 to 4.5 km. Strong second arrivals across the profile, observed at distances of more than 14 km from the shotpoints and interpreted as SP reflections, verified the refraction model. An aeromagnetic survey shows numerous anomalies ranging from 100 to 200γ in the Park and Rabbit Ears Ranges and in the Never Summer Mountains, to 400γ in the Front Range, and to 1200γ over the Medicine Bow Range. Positive anomalies in the Park, Medicine Bow, and Front ranges overlie metamorphic rocks. Magnetic and gravity data suggest that the Never Summer Mountains are separated from the Front Range by a north-trending, steeply east-dipping reverse fault, extending beneath the Front Range along the Colorado River valley. The magnetic data indicate that this fault may connect with a possible fault that is parallel to the Laramie River valley. In the Rabbit Ears Range, a series of magnetic anomalies show that igneous rocks are present in the eastern part of the range. A northeast-trending positive magnetic anomaly, which is parallel to foliation trends reported in Precambrian rocks, extends from the Park Range across the North Park basin to the Medicine Bow Range. On the basis of this anomaly, the high seismic velocity of the Precambrian basement, and computed profiles fitted to the gravity and magnetic data, we infer that much of the basin is underlain by high-density metamorphic rock. As shown by gravity data, the deepest part of the basin is 2.7 km below sea level, resulting in a maximum relief of 6.7 km on the basement, relative to the Medicine Bow Range. A 25-mgal negative gravity anomaly and a zone of negative magnetic anomalies outline a large granitic intrusion in the Park Range, which probably extends northeast beneath the North Park basin and connects with granitic rocks in the Medicine Bow Range.
Colorado↗