Isopach Patterns Research Articles

Constraining the effects of dynamic topography on the development of Late Cretaceous Cordilleran foreland basin, western United States

AbstractDynamic topography refers to the vertical deflection (i.e., uplift and subsidence) of the Earth's surface generated in response to mantle flow. Although dynamic subsidence has been increasingly invoked to explain the subsidence and migration of depocenters in the Late Cretaceous North American Cordilleran foreland basin (CFB), it remains a challenging task to discriminate the effects of dynamic mantle processes from other subsidence mechanisms, and the spatial and temporal scales of dynamic topography is not well known. To unravel the relationship between sedimentary systems, accommodation, and subsidence mechanisms of the CFB through time and space, a high-resolution chronostratigraphic framework was developed for the Upper Cretaceous strata based on a dense data set integrating >600 well logs from multiple basins/regions in Wyoming, Utah, Colorado, and New Mexico, USA. The newly developed stratigraphic framework divides the Upper Cretaceous strata into four chronostratigraphic packages separated by chronostratigraphic surfaces that can be correlated regionally and constrained by ammonite biozones. Regional isopach patterns and shoreline trends constructed for successive time intervals suggest that dynamic subsidence influenced accommodation creation in the CFB starting from ca. 85 Ma, and this wave of subsidence increasingly affected the CFB by ca. 80 Ma as subsidence migrated from the southwest to northeast. During 100–75 Ma, the depocenter migrated from central Utah (dominantly flexural subsidence) to north-central Colorado (dominantly dynamic subsidence). Subsidence within the CFB during 75–66 Ma was controlled by the combined effects of flexural subsidence induced by local Laramide uplifts and dynamic subsidence. Results from this study provide new constraints on the spatio-temporal footprint and migration of large-scale (>400 km × 400 km) dynamic topography at an average rate ranging from ~120 to 60 km/m.y. in the CFB through the Late Cretaceous. The wavelength and location of dynamic topography (subsidence and uplift) generated in response to the subduction of the conjugate Shatsky Rise highly varied through both space and time, probably depending on the evolution of the oceanic plateau (e.g., changes in its location, subduction angle and depth, and buoyancy). Careful, high-resolution reconstruction of regional stratigraphic frameworks using three-dimensional data sets is critical to constrain the influence of dynamic topography. The highly transitory effects of dynamic topography need to be incorporated into future foreland basin models to better reconstruct and predict the formation of foreland basins that may have formed under the combined influence of upper crustal flexural loading and dynamic subcrustal loading associated with large-scale mantle flows.

Initiation of the Western Interior foreland basin

In this issue of Geology, Fuentes et al. (2009, p. 379) present a new subsidence plot and age data from detrital zircons that help to constrain the date of initiation of the foreland basin in Montana (United States). They offer these data as evidence for the resolution of a controversy regarding the initiation of foreland basin sedimentation in the Western Interior. However, their discussion raises the question of what geological data constitute the defi nitive evidence of the foreland basin style of sedimentation, and therefore the criteria that should be used to defi ne its commencement. A useful defi nition of a foreland basin is that it is a depression that develops adjacent and parallel to a mountain belt. Foreland basins form because the mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere to bend, by a process known as lithospheric fl exure. At convergent plate margins, foreland basins develop behind the marginal arc (retroarc or retroforeland type; Jordan, 1995) or above the downgoing continental plate adjacent to a collision zone (peripheral or proforeland type; Miall, 1995). The downward fl exure is accompanied by the uplift of a forebulge in the basement, typically a few hundred kilometers out from the fold-thrust belt, and beyond that there is a shallow depression called the backbulge basin. The relationship between crustal loading and basin formation was fi rst articulated by Price (1973) with respect to the foreland basin of southern Alberta, and subsequent modeling of the Alberta Basin by Beaumont (1981) demonstrated the quantitative link between fl exural loading, the formation of a crustal depression, and its fi lling by syntectonic sedimentation. Jordan (1981) demonstrated another key criterion for the defi nition of the foreland basin style of subsidence and sedimentation: the distinctive isopach pattern of the basin fi ll, elongated parallel to the mountain front and asymmetric in cross section, with a depocenter located close to the contemporaneous fold-thrust belt, the uplift of which serves as the proximal sediment source. Cross (1986) used this criterion to distinguish foreland basin subsidence from that due to subcrustal mantle loading, which yields a much broader, wider pattern of basinal subsidence. The Western Interior basin (of which the Alberta basin and the Rocky Mountain basin are parts) was initiated as a retroarc basin as a result of a fi rst-order change in the plate kinematics of Pangea. This supercontinent, assembled by multiple plate convergence and suture between Ordovician and Permian time, began to fragment by rifting in the Triassic, and by early Middle Jurassic time, oceanic crust was forming off what is now the Atlantic coast of the United States. The North American continent began a long process of northwestward drift, which carried the plate some 70° of longitude westward, relative to the Pacifi c plate, and, some 40° of latitude northward until Paleocene time, followed by a change in trajectory and a subsequent southward drift of ~10° up to the present day (Engebretson et al., 1985). There are numerous indicators of a fi rst-order change in magmatic, tectonic subsidence and sedimentation patterns associated with this change in plate kinematics. The fi rst appearance of westerly-derived detritus from a rising arc or orogen has long been accepted as providing the timing of initiation of the Western Interior foreland basin. Prior to the establishment of the basin, the western continental margin was miogeoclinal in character, with sediment derived from easterly sources (the craton and the Canadian Shield). Ron Blakey and I (in Miall, 2008), designated the

Marine transgressions in the mid-Cretaceous of the Cordilleran foreland basin re-interpreted as orogenic unloading deposits

Abstract A detailed stratigraphic and sedimentologic study of the Early Cenomanian Fish Scales Formation and the Barons Sandstone in southern Alberta, based on detailed core measurement and well log correlation, was undertaken in order to assess the principal controlling factors on the mid-Cretaceous stratigraphic fill of the Cordilleran foreland basin. Fine-grained units in the basin, such as the Fish Scales Formation (Mowry equivalent) and the Early Turonian Second White Specks Formation (Greenhorn equivalent), have traditionally been attributed to deposition during episodes of high eustatic sea levels. However, facies, allostratigraphy, and isopach patterns of the latest Albian Westgate, Fish Scales, mid–late Cenomanian Belle Fourche and Second White Specks formations in southern Alberta suggest that strata were deposited alternately during orogenic loading periods and unloading periods. We interpreted the Fish Scales Formation, a deposit formed during the marine transgression of the Mowry Seaway in the latest Albian–earliest Cenomanian, to have been deposited in a wide shallow interior seaway during an orogenic unloading period. The Barons Sandstone, interbedded with the mudstone of the Fish Scales Formation, is interpreted as a regressive shoreface, distributary channel and barrier island sandstone deposited during the unloading period. We also tentatively interpreted the Second White Specks Formation, a regional stratigraphic marker deposited during the so-called peak eustatic sea level in the Early Turonian, to have been deposited in a wide shallow interior seaway during a period of regional orogenic unloading. This study questions the significance of the Mowry Shale and Greenhorn Formation as indicators of eustatic highstands of sea level, and suggests regional tectonism as the primary control on basin evolution.

Structural Configuration of the Early Cretaceous Cordilleran Foreland‐Basin System and Sevier Thrust Belt, Utah and Colorado

Abstract Stratigraphic and provenance data from Lower Cretaceous rocks in Utah and Colorado and structural evidence from the Sevier belt in west‐central Utah allow recognition of the ties between early thrust‐belt evolution and foreland‐basin system development. Regional isopach patterns of Lower Cretaceous strata define foreland‐basin system depozones. Lower Cretaceous strata in west‐central Utah that thicken westward from ∼100 m to ∼1.2 km were deposited within the flexurally subsiding foredeep depozone. Correlative units in eastern Utah and western Colorado ∼100 m thick were deposited in the back‐bulge depozone. These thickness trends indicate the Lower Cretaceous foreland‐basin system consisted of a foredeep ∼100–180 km wide and forebulge ∼260–460 km wide. A computer‐generated flexural model of the foreland‐basin system produces a reasonable match of the observed basin geometry using a 400‐km‐wide l...

Implications of Jurassic, Cretaceous, and Proterozoic piercing lines for Laramide oblique-slip faulting in New Mexico and rotation of the Colorado Plateau

Research Article| June 01, 1999 Implications of Jurassic, Cretaceous, and Proterozoic piercing lines for Laramide oblique-slip faulting in New Mexico and rotation of the Colorado Plateau Steven M. Cather Steven M. Cather 1New Mexico Bureau of Mines and Mineral Resources, Socorro, New Mexico 87801 Search for other works by this author on: GSW Google Scholar Author and Article Information Steven M. Cather 1New Mexico Bureau of Mines and Mineral Resources, Socorro, New Mexico 87801 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1999) 111 (6): 849–868. https://doi.org/10.1130/0016-7606(1999)111<0849:IOJCAP>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Steven M. Cather; Implications of Jurassic, Cretaceous, and Proterozoic piercing lines for Laramide oblique-slip faulting in New Mexico and rotation of the Colorado Plateau. GSA Bulletin 1999;; 111 (6): 849–868. doi: https://doi.org/10.1130/0016-7606(1999)111<0849:IOJCAP>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Regional isopach patterns and pinch-out data for nine stratigraphic units of Jurassic and Cretaceous age are either permissive or supportive of significant dextral slip of Laramide age along the eastern Colorado Plateau boundary in New Mexico. The best-constrained dextral offset estimates are for the Sand Hill–Nacimiento fault system (20–33 km) and the previously published 13 km estimate for the Defiance monocline, which together yield a cumulative offset of 33–46 km. Mesozoic stratigraphic constraints for other Laramide fault systems are less precise, and typically provide only maximum limits for possible dextral offsets because of widely spaced control points and broad areas of Tertiary erosion. These less precise constraints allow as much as 40–60 km of Laramide dextral slip along what is now the Rio Grande rift and as much as 110 km across the entire breadth of the Laramide deformed zone in central and northern New Mexico.Well-documented dextral offsets of Proterozoic lithologies and structures across the Tusas-Picuris fault system (15 km) and Picuris-Pecos fault (37 km) probably represent minimum Laramide displacements because of the need to account for sinistral components related to other deformations. These displacements, when combined with dextral offsets along Sand Hill–Nacimiento and Defiance structures, yield a minimum dextral offset of ∼85 km for Laramide structures in northern New Mexico. This minimum dextral offset is approximately equivalent to the amount of Laramide crustal shortening on and northward of the Colorado Plateau, a result that argues against nearby Euler pole locations for Laramide rotation of the Colorado Plateau relative to cratonic North America. Geological constraints allow ∼0° to 3° of Laramide clockwise rotation of the Colorado Plateau. Additional clockwise plateau rotation during late Cenozoic development of the Rio Grande rift was 1° to 1.5°. Geological constraints thus indicate that clockwise rotation of the Colorado Plateau from combined Laramide and Rio Grande rift deformations was between about 1° and 4.5°. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Controls on Upper Jurassic sediment distribution in the Durward–Dauntless area, UK Blocks 21/11, 21/16

The Upper Jurassic shallow marine Fulmar sands are widespread in the West Central Graben but have an increasingly irregular distribution when traced westwards across the West Central Shelf (Western Platform). This is strikingly illustrated in the Durward and Dauntless fields (Blocks 21/11 and 21/16), located 20 km west of Kittiwake, where several exploration, appraisal and development wells failed to find the Fulmar sands objective. The main aim of this paper is to offer an explanation for this irregular sand distribution in the Durward/Dauntless area. This study represents an integrated analysis of the thin (50–250 ft) Upper Jurassic succession (equivalent to the Fulmar and Kimmeridge Clay formations) based on around 90 wells and a sub-regional 3D seismic dataset, which covers most of the West Central Shelf. A combination of sedimentological, biostratigraphical and well log criteria has been used to define up to nine genetic depositional sequences bounded by regionally correlatable maximum flooding surfaces. This stratigraphic framework provides a linkage between the previously unpublished Durward Dauntless area and the Kittiwake Field. Typical ‘Fulmar sands’ facies are restricted to the Kimmeridgian in this area and occur in up to five depositional sequences, which extend from the Base Jurassic unconformity (earliest Kimmeridgian) up to the eudoxus and autissiodorensis maximum flooding surfaces (mfs) (latest Kimmeridgian). These sequences display marked lateral facies changes from sand to mud, while stratal patterns and thickness variations indicate onlap against earlier deposits. This is in striking contrast to the younger mud-dominated depositional sequences (Volgian to Ryazanian), which display complex local subsidence patterns bearing little relationship to Fulmar sand isopach patterns within the Kimmeridgian. The 3D seismic data have enabled mapping of the Base Cretaceous, Top Zechstein Salt and Top Basement (pre-Zechstein), but is unable to directly resolve the thin Upper Jurassic interval. However, these data have enabled a regional structural/stratigraphic model to be developed, particularly in relation to the effects of the nature and rate of accommodation space creation. Conclusions derived from the 3D seismic interpretations have been integrated with those from the well-based sequence stratigraphic studies. The resulting geological model for the Upper Jurassic concludes that Fulmar sand distribution was largely controlled by pre-existing topography, which had evolved during a significant period of (late Triassic–pre Upper Jurassic) subaerial exposure. This topography was critical in controlling highstand sand distribution and its ultimate preservation potential. The importance of pre-Upper Jurassic topography in determining accommodation space became secondary to dissolution of the Zechstein during the suspension-dominated sedimentation of the Volgian and Lower Cretaceous. These local controls vary on a kilometre scale and are superimposed upon the longer wavelength control of regional eastwards dip, which evolved from the cymodoce mfs until the Albian and caused a general westwards onlap of Upper Jurassic and early Cretaceous successions across the West Central Shelf. The model suggests that 3D topographic reconstruction of the pre-Jurassic substrate is the single most critical factor in predicting Fulmar reservoir distribution on the transgressed surface of the West Central Shelf.

‘Laramide’ events: Mid North Sea High (UK Quadrants 38 &amp; 39)

The Mid North Sea High is a broad, approximately east-trending structural high that extends from the coast of the Scottish Borders region to the UK North Sea median line. Recently acquired seismic reflection profiles were used to map isopach patterns of the Chalk Group (Upper Cretaceous and lowermost Paleocene), of the combined Montrose and Moray groups (Paleocene and lowermost Eocene), and of the lower Stronsay Group (lower Eocene) in UK Quadrants 38 and 39, on the eastern Mid North Sea High. In an anomalous and undrilled part of this area, the Chalk Group thins over an area broadly centred on a long lived, buried, NNW-trending structural high with a core largely comprised of Devono-Carboniferous sediments. In contrast, the combined Montrose and Moray groups and the lower Stronsay Group sediments thicken over the buried high. We informally name the buried high the α Ridge. Signal processing techniques were applied to the original stack sections to help clarify the geometry of seismic reflections, especially from within the Chalk Group and Palaeogene successions of the anomalous zone, and to interpret deep erosion at the top of the Chalk Group that probably occurred in Danian times. The area of deeply eroded Chalk was subsequently buried beneath an anomalously thick Palaeogene succession. The area of eroded Chalk is more extensive than the α Ridge and extends northwards beyond the survey area. From a regional perspective, the processes that may have controlled the observed depositional pattern are discussed. It is considered whether rapidly changing tectonic stress may have caused local ‘Laramide’ (mid Paleocene–Danian) uplift and erosion of the α Ridge and its immediately surrounding area, swiftly followed by enhanced subsidence (inversion) and deposition in the mid Paleocene (Danian), or whether the stratal pattern is better explained by the infilling of a large erosional hollow; mechanisms involving the local halokinesis and/or dissolution of Zechstein salt are discounted. We conclude that additional seismic and palaeogeographical information is required to fully test the models proposed in this paper.

Three-dimensional computer-assisted basin modelling to generate exploration target areas: an example from the late Archaean-early Proterozoic Transvaal Supergroup, South Africa

Second- and third-order fault-bounded Precambrian basins frequently host deposits of the sedimentary massive sulphide group. Three-dimensional geometric modelling of the thickness of preserved basin-fill successions of the Transvaal Supergroup, using DATAMINE software, and residual gravity modelling of the contemporary basement floor, help delineate areas of exploration potential in this unit. Two main depositional axes are tentatively identified for the basal volcano-sedimentary protobasinal Transvaal successions. A sheet-like geometry was indicated for the succeeding Black Reef sandstones and Chuniespoort Group chemical sedimentary rocks. The uppermost Pretoria Group thickness model delineates eastern and western second-order basins separated by a central submerged palaeohigh. A similar isopach pattern is noted for the thick shales of the Silverton Formation in this group, with, in addition, a well-defined third-order basin in the northwest of the western second-order basin. The residual gravity model indicates two linear palaeovalleys adjacent to this western basin, one coincident with one of the axes inferred for the protobasinal rocks. The fault-bounded second- and third-order basins and depositional axes postulated here are consistent with known geological data and suggested sedimentation models. Cumulative distortions implicit in the DATAMINE computer modelling technique are reduced when the method is applied on the basin-wide scale, enabling identification of regional exploration target areas rather than immediate prospecting targets.

Late Cretaceous-Paleocene synorogenic sedimentation and kinematic history of the Sevier thrust belt, northeast Utah and southwest Wyoming

Integration of cross-cutting structural relationships, overlapping sedimentary units, new conglomerate provenance data, and radiometric and palynological dates provides a basis for reinterpretation of the distribution and timing of Late Cretaceous through Paleocene thrust faulting in the northeast Utah-southwest Wyoming part of the Sevier thrust belt. These data indicate a general eastward progression of deformation that was punctuated by local out-of-sequence and hinterlandward-verging events. Provenance data delimit a sequential restoration of a regional cross section. The principal thrust systems in northeast Utah and southwest Wyoming are the Willard, Ogden, Crawford, Absaroka, and Hogsback thrusts. The Willard is the westernmost, structurally highest, and oldest of the thrusts; it carries a unique section of thick Proterozoic sedimentary rocks, as well as Paleozoic rocks, and was folded during displacement on younger thrust systems. The next youngest thrust system is the Ogden, which comprises several basement-rooted imbricate thrusts that together form a large antiformal stack with a structural culmination in the Wasatch Range. Growth of the Wasatch culmination took place during Coniacian through Paleocene time, contemporaneous with sequential displacement on the frontal Crawford, Absaroka, and Hogsback thrusts. Total shortening in this part of the thrust belt was ∼100 km, and structural relief of ∼25 km developed in the area of the Wasatch culmination. During Coniacian through Paleocene time, thrusting followed an overall eastward progression that was interrupted by local out-of-sequence and hinterlandward-verging events. Several episodes of synchronous displacement on two or more thrusts can be demonstrated. Shortening occurred in three main episodes. The first episode (∼89-84 Ma) involved ∼33 km of shortening on the Crawford thrust and its footwall imbricates. Approximately 19 km of structural relief on the basement-cover contact developed in the area of the Wasatch culmination. The second episode (∼84-62 Ma, with a break between ∼75-69 Ma) involved ∼30 km of shortening, mainly on the Absaroka thrust, and development of an additional ∼6 km of structural relief in the culmination. The third episode of shortening (∼56-50 Ma) took place on the Hogsback thrust, involved ∼21 km of horizontal shortening, and produced no significant increase in structural relief in the culmination. Long-term rates of shortening ranged between 3.0 mm/yr and 6.6 mm/yr. These three episodes of shortening produced three large accumulations of synorogenic conglomerate, totaling ∼3 km in thickness. The Henefer Formation and Echo Canyon and Weber Canyon Conglomerates were deposited during Crawford thrusting. The Evanston Formation was deposited during and after Absaroka thrusting, and the lower conglomeratic part of the Wasatch Formation was deposited during and after Hogsback thrusting. Most of the sediment in these synorogenic units, however, was derived from repeated uplift of the Willard thrust sheet and from the eastern flank of the Wasatch culmination in the rear part of the thrust belt. Only local, minor accumulations were derived from the frontal ramp anticlines. Sediment accumulation and structural deformation were generally out-of-phase. Periods of regional shortening and uplift were marked by development of unconformities and sediment bypassing to distal parts of the foreland basin. Periods of structural inactivity were marked by accumulation of aerially widespread, braided-river conglomerate on top of the thrust belt. One exception to this pattern is the Henefer-Echo Canyon-Weber Canyon conglomerate deposit, which contains evidence of progressive deformation in close proximity to the tip of the Crawford thrust. Comparison of the sequential restoration with the Late Cretaceous subsidence history and isopach patterns in the distal foreland basin of western Wyoming demonstrates that the principal controls on regional subsidence and sediment supply were the growth and erosion of the Wasatch culmination. Growth of the duplex beneath the culmination may have been a means of maintaining critical taper in the thrust wedge.

Most recent fall deposits of Ksudach Volcano, Kamchatka, Russia

Three of four Plinian eruptions from Ksudach Volcano are among the four largest explosive eruptions in southern Kamchatka during the past 2000 years. The earliest of the eruptions was voluminous and was accompanied by an ignimbrite and the fifth and most recent caldera collapse event at Ksudach. The isopach pattern is consistent with a column height of 23 km. The three more recent and smaller eruptions were from the Shtyubel' Cone, within the fifth caldera. Using isopach and grain size isopleth patterns, column heights ranged from ≥ 10 to 22 km. Although the oldest eruption may have produced a large acidity peak in the Greenland ice, the three Shtyubel' events may not be related to major acid deposition. Thus it is possible that few if any of the uncorrelated acidity peaks of the past 2000 years in Greenland ice cores result from eruptions in southern Kamchatka.

Cause of tectonic reactivation and subtle uplifts in the Rocky Mountain region and its effect on the stratigraphic record

Stratigraphic studies show that widespread, albeit subtle, topographic uplifts have occurred throughout the U.S. Rocky Mountain region during middle and late Mesozoic time. Individual paleotopographic highs generally have wavelengths on the order of tens of kilometres and amplitudes on the scale of metres. In places, these features correspond to sites of previous or later deformation and so suggest the possibility of tectonic reactivation along pre-existing zones of structural weakness in the crust. Observations of modern features and modeling studies indicate that uplifts of small magnitude are both a common and expected result of changes in intraplate stress levels. Finite-element modeling suggests that broad-wavelength, low-amplitude topography can develop in a heterogeneous elastic plate under high-stress magnitudes along preexisting faults and under low-stress magnitudes where zones of high and low strength are juxtaposed. Although these features are small, they have sufficient topography to bring about large changes in paleocurrent patterns for low-gradient streams and significantly affect isopach patterns. Although subtle uplifts from this cause are difficult to predict, they are likely a common occurrence and may be the most dramatic features in an area that is otherwise tectonically quiescent. Thus, subtle uplift may be a background noise rather than a harbinger of regional orogenesis.

Structural Development of Billings and McKenzie Counties, Southwestern North Dakota

Billings and southern McKenzie counties contain about 40 active oil and gas fields. In the same area, two major structural highs and several minor ones can be recognized. The Billings anticline extends approximately 60 km (18 mi) along a north-south line in central Billings County and is composed of two parallel folds. A second major structure, the Rough Rider anticline, lies west of the Billings anticline and also extends about 60 km (18 mi) along a north-south line from north-central Billings County into southern McKenzie County. Both of these structures are fault bounded on their eastern sides and are sites of significant hydrocarbon accumulation. Episodes of tectonic activity within the area were identified by study of isopach patterns derived from wireline log picks and by subsidence analysis. Although the subsidence of the Williston basin was the principal regional tectonic activity, the structural features in Billings and McKenzie counties were intermittently decoupled from the larger scale basin movement, producing local highs. The two major positive features, as well as several minor ones, have behaved independently of each other through time. Most of the development of these structures took place during the Devonian and Mississippian.

Morphology of the Frontal fault zone, southwest Oklahoma: Implications for deformation and deposition in the Wichita uplift and Anadarko basin

Research Article| July 01, 1990 Morphology of the Frontal fault zone, southwest Oklahoma: Implications for deformation and deposition in the Wichita uplift and Anadarko basin David A. McConnell; David A. McConnell 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: GSW Google Scholar Michael J. Goydas; Michael J. Goydas 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: GSW Google Scholar Graham N. Smith; Graham N. Smith 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: GSW Google Scholar John P. Chitwood John P. Chitwood 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: GSW Google Scholar Author and Article Information David A. McConnell 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 Michael J. Goydas 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 Graham N. Smith 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 John P. Chitwood 1Department of Geology, Kansas State University, Manhattan, Kansas 66506 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1990) 18 (7): 634–637. https://doi.org/10.1130/0091-7613(1990)018<0634:MOTFFZ>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation David A. McConnell, Michael J. Goydas, Graham N. Smith, John P. Chitwood; Morphology of the Frontal fault zone, southwest Oklahoma: Implications for deformation and deposition in the Wichita uplift and Anadarko basin. Geology 1990;; 18 (7): 634–637. doi: https://doi.org/10.1130/0091-7613(1990)018<0634:MOTFFZ>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Structural fabrics along the northern margin of the Wichita uplift, southwestern Oklahoma, are compared with depositional patterns in the adjacent Anadarko basin. The Frontal fault zone, the structural transition between the uplift and basin, is divisible into three segments that reflect the partitioning of deformation along the northern margin of the uplift. Variations in Pennsylvanian isopach patterns within the Anadarko basin suggest changing conditions of tectonic loading along the basin's southern margin. Anomalously thin sections of syntectonic rocks in the deep basin are interpreted to have been deposited on the crests of growing anticlines. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Determination of offset across the northern margin of the Wichita uplift, southwest Oklahoma

The Wichita uplift represents a tectonic element within the Ancestral Rocky Mountains, a series of basement-involved uplifts and associated basins within the foreland of the Ouachita orogen. Contrasting tectonic models for the evolution of the Wichita uplift are evaluated by (i) analyzing the suite of structures within the Frontal fault zone, which separates the uplift from the adjoining Anadarko basin, and (ii) undertaking a palinspastic restoration of Houton Group (Late Ordovician-Devonian) thickness trends between the basin and the Frontal fault zone to estimate the magnitude and sense of offset across the principal uplift-bounding faults. Cross sections from uplift to basin show basement-involved thrusts and folds similar to those recognized within the Laramide (Late Cretaceous-Tertiary) foreland of the Rocky Mountains. Structural patterns in map view possess elements that have been previously interpreted as resulting from reverse slip and/or left slip on the uplift-bounding faults. Palinspastic restoration of isopach patterns between the Frontal fault zone and Anadarko basin indicates that offset across the frontal faults may be explained by oblique slip (left reverse slip) on the uplift bounding faults. The component of left slip is nearly an order off magnitude less than proposed in some previous models of Carboniferous tectonism within the foreland of the Ouachita orogen.

Lithofacies and paleogeography of the Conasauga Group, (Middle and Late Cambrian) in the Valley and Ridge province of east Tennessee

A comprehensive data base for the Conasauga Group (Middle and Late Cambrian) throughout the Valley and Ridge province in east Tennessee was compiled from published and unpublished sources. Lithofacies and isopach maps and stratigraphic cross sections were constructed from this data base on both present-day and palinspastic bases to define regional depositional patterns of the Conasauga Group. Isopach and lithofacies trends recognized on present-day base maps are generally consistent with those previously recognized. Lithofacies data are consistent with a shelf-intrashelf-basin-carbonate-ramp model proposed by other investigators for the Nolichucky Shale. Our study suggests that the southern edge of an intrashelf basin recognized within the Conasauga Group in southwest Virginia was 20 to 50 km southwest of present-day Knoxville. Palinspastic-base lithofacies and isopach patterns for the Conasauga Group in east Tennessee suggest (1) the existence of a generally elliptical intrashelf basin that closes to the southwest and the north east; (2) that the eastern margin of the intrashelf basin consists of shaly limestone and dolostone, the dolostone being dominant eastward; (3) that basin sediments are limestone, shale, and shaly limestone (40%-80% limestone); and (4) that the western basin margin sediments are mostly calcareous shale and siltstone (20%-60% limestone) that become terrigenous west of the basin. A sub-basin within the regional intrashelf basin has been identified. The axis of this sub-basin is oriented northwest, perpendicular to the regional trend of the shelf and Appalachian structure. Approximately 2,900 ft (883 m) of Conasauga strata accumulated in the subbasin, which first appeared during Pumpkin Valley Shale deposition and persisted through Maynardville Limestone deposition. We interpret the abrupt thickening at the margin of this basin to result from basement faulting, which produced a graben that subsided intermittently during basin filling. This structure may have economic significance in that there is an apparent correlation between the margin of this second-order basin and zinc mineralization in overlying carbonates of the Knox Group.

Geology of Middle to Upper Ordovician Sebree Trough Northwest of Cincinnati Arch, Ohio, Indiana, and Kentucky: ABSTRACT

The Sebree trough, which has attracted interest in hydrocarbon exploration, is a broadly linear, northeast-oriented, troughlike structure northwest of the Cincinnati arch that can be traced from western Ohio through southeastern Indiana to western Kentucky. The post-Black River, pre-upper Kope succession of the Sebree trough differs markedly in lithology from that of the Cincinnati arch, in which limestones dominate (Trenton and Lexington Limestones), in that it consists mainly of dark-brown to grayish shales (Utica of drillers). The Sebree trough is not displayed by the isopach pattern of the Black River, nor by that of post-Kope strata. Apparently, this feature is restricted to the upper Middle and lower Upper Ordovician. Absence of biostratigraphic control in the Utica, as well as poor well control in the area bordering the Cincinnati arch carbonate region, made previous interpretations of the stratigraphic relations between the Utica and the Lexington-Trenton hypothetical. Recent detailed study of two cores from eastern Indiana and one from western Ohio led to the discovery of a succession of biostratigraphically diagnostic graptolites in the Utica that can be tied into that of the C. spiniferus and C.pygmaeus zones in the Utica Shale of New York. The new evidence shows that at leastmore » the major parts of the Utica and the Lexington-Trenton are correlatives, although these units are developed in quite different facies.« less

Depositional Systems and Reservoir Quality of Clinton Sandstone, Guernsey County, Ohio: ABSTRACT

The Lower Silurian Clinton sandstone is the best producer of gas and oil in eastern Ohio. Successful exploration for its subtle stratigraphic traps requires detailed knowledge of its depositional systems, which were defined by sandstone thickness maps, gamma-ray log cross sections covering a 25-mi area, log signatures, and four slice thickness maps. Two cores and some thin sections helped substantiate environmental interpretations based on logs. These deltaic deposits produce from multistory and laterally discontinuous distributary mouth bars, distributary channels, and delta-plain point bars that are predictably interrelated, each having a unique isopach pattern, log signature, and production characteristics. Distributary mouth-bar reservoirs occur in more than 70% of the wells. They have coarsening-upward log signatures and elongate isopach patterns, and are 0-22 ft thick. They also exhibit poor production, with median payout times exceeding 5 years. Distributary channel-fill reservoirs are superimposed on underlying mouth-bar deposits. They have blocky log signatures and form linear, narrow shoestrings. These reservoirs are found in 18% of the wells, and more than 70% of the wells reach payout in less than 2 years. Meander point-bar reservoirs are the best economically but are encountered in only 8% of the wells. These fining-upward, ovoid to kidney-shaped reservoirs aremore » prolific gas producers and range up to 25 ft thick. Isopach maps define and project the extent of distributary channels, but point bars, because they are thin, are not apparent and must be identified by cross sections, log signatures, and stratigraphic position.« less

Comment and Reply on “Isopach pattern of the Lower Cambrian Zabriskie Quartzite, Death Valley region, California-Nevada: How useful in tectonic reconstructions?”

Research Article| September 01, 1986 Comment and Reply on “Isopach pattern of the Lower Cambrian Zabriskie Quartzite, Death Valley region, California-Nevada: How useful in tectonic reconstructions?”: COMMENT John H. Stewart John H. Stewart 1U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Author and Article Information John H. Stewart 1U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1986) 14 (9): 810–811. https://doi.org/10.1130/0091-7613(1986)14<810:CAROIP>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation John H. Stewart; Comment and Reply on “Isopach pattern of the Lower Cambrian Zabriskie Quartzite, Death Valley region, California-Nevada: How useful in tectonic reconstructions?”: COMMENT. Geology 1986;; 14 (9): 810–811. doi: https://doi.org/10.1130/0091-7613(1986)14<810:CAROIP>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract No Abstract Available. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Comment and Reply on “Isopach pattern of the Lower Cambrian Zabriskie Quartzite, Death Valley region, California-Nevada: How useful in tectonic reconstructions?”

Comment and Reply on “Isopach pattern of the Lower Cambrian Zabriskie Quartzite, Death Valley region, California-Nevada: How useful in tectonic reconstructions?”

Isopach pattern of the Lower Cambrian Zabriskie Quartzite, Death Valley region, California-Nevada: How useful in tectonic reconstructions?

New thickness measurements of the Lower Cambrian Zabriskie Quartzite indicate an original isopach pattern much less regular than once supposed, and thus less useful as an indicator of the magnitude of lateral slip on the Death Valley fault system. But within a wide range of possible restorations, the isopachs conform with the locations of Proterozoic highlands and basins. The Zabriskie Quartzite, being mature, laterally persistent, and, unlike the underlying formations, devoid of evidence of rifting, apparently records the beginning of the passive stage of the developing Cordilleran miogeocline.