Fractures in the northern plains, stream patterns, and the midcontinent stress field

1987 ◽  
Vol 24 (6) ◽  
pp. 1086-1097 ◽  
Author(s):  
Mel R. Stauffer ◽  
Don J. Gendzwill
Keyword(s):  
Stress Field ◽  
Horizontal Stress ◽  
The Body ◽  
North American Plate ◽  
Plate Motion ◽  
Viscous Drag ◽  
Near Surface ◽  
The North ◽  
Elastic Rebound ◽  
Western North Dakota

Fractures in Late Cretaceous to Late Pleistocene sediments in Saskatchewan, eastern Montana, and western North Dakota form two vertical, orthogonal sets trending northeast–southwest and northwest–southeast. The pattern is consistent, regardless of rock type or age (except for concretionary sandstone). Both sets appear to be extensional in origin and are similar in character to joints in Alberta. Modem stream valleys also trend in the same two dominant directions and may be controlled by the underlying fractures.Elevation variations on the sub-Mannville (Early Cretaceous) unconformity form a rectilinear pattern also parallel to the fracture sets, suggesting that fracturing was initiated at least as early as Late Jurassic. It may have begun earlier, but there are insufficient data at present to extend the time of initiation.We interpret the fractures as the result of vertical uplift together with plate motion: the westward drift of North America. The northeast–southwest-directed maximum principal horizontal stress of the midcontinent stress field is generated by viscous drag effects between the North American plate and the mantle. Vertical uplift, erosion, or both together produce a horizontal tensile state in near-surface materials, and with the addition of a directed horizontal stress through plate motion, vertical tension cracks are generated parallel to that horizontal stress (northeast–southwest). Nearly instantaneous elastic rebound results in the production of second-order joints (northwest–southeast) perpendicular to the first. In this manner, the body of rock is being subjected with time to complex alternation of northeast–southwest and northwest–southeast horizontal stresses, resulting in the continuous and contemporaneous production of two perpendicular extensional joint sets.

Assessing the geodynamics of strongly arcuate subduction zones in the eastern Caribbean subduction setting

2020 ◽  
Author(s):  
Menno Fraters ◽  
Wim Spakman ◽  
Cedric Thieulot ◽  
Douwe Van Hinsbergen
Keyword(s):  
Stress Field ◽  
Subduction Zones ◽  
Focal Mechanisms ◽  
North American Plate ◽  
Plate Motion ◽  
Caribbean Region ◽  
The North ◽  
Eastern Caribbean ◽  
Subduction Setting ◽  
Subduction System

<p>The eastern Caribbean Lesser-Antilles subduction system is a strongly arcuate subduction system. We have investigated the dynamics of this system through numerical modelling, demonstrating the developed capabilities and computational feasibility for assessing the 3D complexity and geodynamics of natural subductionsystems and applied this to the eastern Caribbean region. We show the geodynamic feasibility of westward directed trench-parallel slab transport through the mantle, i.e. slab dragging, on the northern segment of the slab, while the eastern segment of the slab is subducting by a mantle-stationary trench. The resistance of the mantle against slab dragging by the North American plate motion, as well as the deformation associated with the arcuate geometry of the slab, creates a complex 3D stress field in the slab that deviates strongly from the classical view of slab-dip aligned orientation of slab stress. More generally this means that the process of slab dragging may reveal itself in the focal mechanisms of intermediate and deep earthquakes. The characteristics of the arcuate subduction such as slab dragging and a complex 3D stress field as studied in the Caribbean region can be more generically applied to other arcuate subduction systems as well, such as the Izu-Bonin-Marianas or the Aleutians-Alaskasystems, where anomalous focal mechanisms of slabs are observed.</p>

Geodynamic implications of the Cenozoic stress field on Seymour Island, West Antarctica

2008 ◽  
Vol 20 (2) ◽  
pp. 173-184 ◽  
Author(s):  
A. Maestro ◽  
J. López-Martínez ◽  
F. Bohoyo ◽  
M. Montes ◽  
F. Nozal ◽  
...  
Keyword(s):  
Stress Field ◽  
Antarctic Peninsula ◽  
Horizontal Stress ◽  
Weddell Sea ◽  
Scotia Sea ◽  
Compressional Stress ◽  
The North ◽  
Stress States ◽  
Bransfield Basin ◽  
Minimum Horizontal Stress

AbstractPalaeostress inferred from brittle mesostructures in Seymour (Marambio) Island indicates a Cenozoic to Recent origin for an extensional stress field, with only local compressional stress states. Minimum horizontal stress (σ3) orientations are scattered about two main NE–SW and NW–SE modes suggesting that two stress sources have been responsible for the dominant minimum horizontal stress directions in the north-western Weddell Sea. Extensional structures within a broad-scale compressional stress field can be linked to both the decrease in relative stress magnitudes from active margins to intraplate regions and the rifting processes that occurred in the northern Weddell Sea. Stress states with NW–SE trending σ3are compatible with back-arc extension along the eastern Antarctic Peninsula. We interpret this as due to the opening of the Larsen Basin during upper Cretaceous to Eocene and to the spreading, from Pliocene to present, of the Bransfield Basin (western Antarctic Peninsula), both due to former Phoenix Plate subduction under the Antarctic Plate. NE–SW σ3orientations could be expressions of continental fragmentation of the northern Antarctic Peninsula controlling eastwards drifting of the South Orkney microcontinent and other submerged continental blocks of the southern Scotia Sea.

scholarly journals Plate Motion and Earth Orientation

1988 ◽  
Vol 129 ◽  
pp. 363-364
Author(s):  
A. Mallama ◽  
M. Kao
Keyword(s):  
A Priori ◽  
Terrestrial Reference Frame ◽  
North American Plate ◽  
Plate Motion ◽  
Earth Orientation ◽  
Root Mean Square Residual ◽  
The North ◽  
Tectonic Motion ◽  
Analysis System ◽  
Simple Rotation

Earth orientation series are linked to the terrestrial reference frame in which the observing site locations are measured. The effect of tectonic motion is a simple rotation for any given plate, but the overall effect depends on the distribution of sites. The magnitude of this motion is large enough to be evident in the data. For example, the coefficient of rotation for the North American plate around the Earth's Y-axis is −0.8 millarcseconds per year in the AMO-2 plate motion model of Minster and Jordan. The VLBI analysis system at NASA/GSFC for computing earth orientation series has recently been enhanced by including the Minster and Jordan model for a priori tectonic effects. Tests indicate that the weighted-root-mean-square residual of observations to the solution is decreased by using this model.

Breakouts in Alberta and stress in the North American plate

1983 ◽  
Vol 20 (9) ◽  
pp. 1445-1455 ◽  
Author(s):  
C. K. Fordjor ◽  
J. S. Bell ◽  
D. I. Gough
Keyword(s):  
United States ◽  
North American ◽  
Horizontal Stress ◽  
The United States ◽  
Oil Wells ◽  
North American Plate ◽  
Mantle Flow ◽  
Orientation Data ◽  
The North ◽  
Canadian Basin

The paper reports a detailed statistical study of breakout azimuths in 48 oil wells widely distributed in the Alberta sedimentary basin, bringing the number of oil wells contributing azimuths to 94 for the western Canadian basin. The azimuths show significant regional variation between the northern, central, and southern parts of the basin. Twenty-one wells, in which breakouts cover depth ranges greater than 600 m, were used to investigate regression of breakout azimuths on depth. Ten wells give positive regression coefficients, 11 are negative, and no coefficient is significant at 95% confidence level. If the dominant northwest–southeast orientation of the long axes of breakouts gives the orientation of the lesser horizontal principal stress Sh, following the hypothesis of Bell and Gough, the inferred stress orientations indicate that throughout the whole basin the direction of the maximum horizontal stress SH is northeast–southwest. Stress measurements, by strain-relief techniques in a mine and from hydraulic fracture in wells, support the stress orientation given by the breakouts. The insignificant regression of breakout azimuths on depth supports the view that the orientation data represent stress in the lithosphere rather than in the sediments only. Directions of the lesser horizontal compression Sh, from Zoback and Zoback in the United States and from breakout studies in western Canada, are combined to suggest that the Mid-Continent stress province of North America may include the western Canadian basin and the Canadian Shield as well as the central United States. Coherent stress with the observed orientation, over the continent east of the Rocky Mountains, would result from northeastward basal drag on the North American plate, as Zoback and Zoback have pointed out. Basal drag to the northeast could arise either if the plate were sliding southwestward over a passive asthenosphere, as suggested by Zoback and Zoback, or if northeastward mantle flow were driving the asthenosphere and the plate northeastward.

Stress magnitudes in the crust: constraints from stress orientation and relative magnitude data

1991 ◽  
Vol 337 (1645) ◽  
pp. 181-194 ◽  
Keyword(s):  
Stress Field ◽  
Plate Boundary ◽  
Horizontal Stress ◽  
Crustal Thickening ◽  
Viscous Drag ◽  
Stress Orientation ◽  
Relative Stress ◽  
Stress Orientations ◽  
Intraplate Stress

The World Stress Map Project is a global cooperative effort to compile and interpret data on the orientation and relative magnitudes of the contemporary in situ tectonic stress field in the Earth's lithosphere. Horizontal stress orientations show regionally uniform patterns throughout many continental intraplate regions. These regional intraplate stress fields are consistent over regions 1000-5000 km wide or ca . 100 times the thickness of the upper brittle part of the lithosphere ( ca . 20 km) and about 10-15 times the thickness of typical continental lithosphere ( ca . 150-200 km). Relative stress magnitudes or stress regimes in the lithosphere are inferred from direct in situ stress measurements and from the style of active faulting. The intraplate stress field in both the oceans and continents is largely compressional with one or both of the horizontal stresses greater than the vertical stress. The regionally uniform horizontal intraplate stress orientations are generally consistent with either relative or absolute plate motions indicating that plate-boundary forces dominate the stress distribution within the plates. Since most regions of normal faulting occur in areas of high elevation, the extensional stress régimes in these areas can be attributed to superimposed bouyancy forces related to crustal thickening and/or lithosphere thinning; stresses derived from these bouyancy forces locally exceed mid-plate compressional stresses. Evaluating the effect of viscous drag forces acting on the plates is difficult. Simple driving or resisting drag models (with shear tractions acting parallel or antiparallel to plate motion) are consistent with stress orientation data; however, the large lateral stress gradients across broad plates required to balance these tractions are not observed in the relative stress magnitude data. Current models of stresses due to whole mantle flow inferred from seismic tomography models (and with the inclusion of the effect of high density slabs) predict a general compressional stress state within continents but do not match the broad-scale horizontal stress orientations. The broad regionally uniform intraplate stress orientations are best correlated with compressional plate-boundary forces and the geometry of the plate boundaries.

scholarly journals The Crustal Stress Field of Germany - A Refined Prediction

2021 ◽  
Author(s):  
Steffen Ahlers ◽  
Luisa Röckel ◽  
Tobias Hergert ◽  
Karsten Reiter ◽  
Oliver Heidbach ◽  
...  
Keyword(s):  
Stress Field ◽  
Sedimentary Basins ◽  
Horizontal Stress ◽  
Rock Properties ◽  
Upper Rhine Graben ◽  
Calibration Data ◽  
Directional Drilling ◽  
In Situ Data ◽  
The North ◽  
The Absolute

Abstract Information about the absolute stress state in the upper crust plays a crucial role in the planning and execution of e.g., directional drilling, stimulation and exploitation of geothermal and hydrocarbon reservoirs. Since many of these applications are related to sediments, we present a refined geomechanical-numerical model for Germany with focus on sedimentary basins, able to predict the complete 3D stress tensor. The lateral resolution of the model is 2.5 km, the vertical resolution about 250 m. Our model contains 22 units with focus on the sedimentary layers parameterized with individual rock properties. The model results show an overall good fit with magnitude data of the minimum (Shmin) and maximum horizontal stress (SHmax) that are used for the model calibration. The mean of the absolute stress differences between these calibration data and the model results is 4.6 MPa for Shmin and 6.4 MPa for SHmax. In addition, our predicted stress field shows good agreement to several supplementary in situ data from the North German Basin, the Upper Rhine Graben and the Molasse Basin.

Hydrochronology of a proposed deep geological repository for low- and intermediate-level nuclear waste in southern Ontario from U–Pb dating of secondary minerals: response to Silurian and Cretaceous events

2020 ◽  
Vol 57 (4) ◽  
pp. 464-476 ◽  
Author(s):  
D.W. Davis ◽  
C.N. Sutcliffe ◽  
A.M. Thibodeau ◽  
J. Spalding ◽  
D. Schneider ◽  
...  
Keyword(s):  
Carbonate Platform ◽  
Sedimentary Rocks ◽  
North American Plate ◽  
Deep Geological Repository ◽  
Near Surface ◽  
Southern Ontario ◽  
The North ◽  
Nuclear Site ◽  
Geological Repository ◽  
Carbonate Formations

A record of fluid flow has been documented within a Paleozoic carbonate platform sequence by U–Pb dating of calcite in veins and vugs from rock core sampled through a shallowly dipping sequence of sedimentary rocks beneath the Bruce nuclear site, Ontario, Canada. Secondary calcite from >650 m deep Ordovician carbonate rocks yields a Silurian age of 434 ± 5 Ma possibly related to infiltration of seawater from overlying evaporitic basins as well as hydrothermal solutions that infiltrated from below. In contrast, near-surface Devonian rocks mostly give vein infill ages over the range of 80–100 Ma with evidence for younger infill down to 50 Ma. Vein calcite samples previously dated from surface outcrops of Ordovician carbonate exposed up to 500 km to the east yielded similar U–Pb ages. Coincidence of near-surface vein calcite ages indicates widespread vein emplacement synchronous with a change in direction of motion of the North American plate as well as possible erosional unroofing following passage of the region over the Great Meteor hotspot approximately 125 Myr ago. Deeper carbonate formations have remained apparently impermeable to post-Paleozoic disturbance despite these perturbations.

Determining contemporary stress directions from neotectonic joint systems

1991 ◽  
Vol 337 (1645) ◽  
pp. 29-40 ◽  
Keyword(s):  
Stress Field ◽  
Fault Plane ◽  
Horizontal Stress ◽  
Tectonic Stress ◽  
Stress Fields ◽  
Ebro Basin ◽  
Fault Plane Solutions ◽  
Near Surface ◽  
Initiation And Propagation

A neotectonic joint is a crack which propagated in a tectonic stress field that has persisted with little or no change of orientation until the present day. Investigating neotectonic joints is of value because the approximate orientation of the contemporary stress field can be inferred from them. Although exposed neotectonic joints in the flat-lying sedimentary rocks of some cratons are related to regional stress fields, their initiation and propagation occurred close to the Earth’s surface. For example, neotectonic joints in the centre of the Ebro basin (N. Spain) preferentially developed in a thin, near-surface channel sited within a sequence of weak Miocene limestones underlying the upper levels of plateaux. The Ebro basin joints strike uniformly NNW-SSE throughout an area of at least 10 000 km 2 and they are parallel or subparallel to the direction of greatest horizontal stress extrapolated from in situ stress measurements and fault-plane solutions of earthquakes.

THE STRESS FIELD OF THE NORTH WEST SHELF AND WELLBORE STABILITY

1993 ◽  
Vol 33 (1) ◽  
pp. 373 ◽  
Author(s):  
R.R. Millis ◽  
A.F. Williams
Keyword(s):  
Stress Field ◽  
Horizontal Stress ◽  
Strike Slip ◽  
Wellbore Stability ◽  
Upper And Lower Bounds ◽  
Theoretical Modelling ◽  
Elliptical Cross ◽  
North West ◽  
The North ◽  
Timor Sea

Boreholes drilled in the search for hydrocarbons in the Barrow-Dampier Sub-Basin (North West Shelf, Australia) commonly exhibit an elliptical cross-section believed to be due to stress-induced wellbore failure known as borehole breakout. The azimuths of the long axes of 138 discrete breakouts identified in nine different wells in the Barrow-Dampier show a consistent 010°−030°N trend implying that maximum horizontal compressive stress is oriented 100°−12G°N.The orientation of horizontal stress determined in this study (and that from the Timor Sea area which is rotated some 50°−60° with respect to the Barrow-Dampier) is consistent with that derived from theoretical modelling of the stress within the Indo-Australian plate based on the plate tectonic forces acting on its boundaries. The rotation of the horizontal stress orientations along the North West Shelf, between the Barrow-Dampier and the Timor Sea, is a reflection of the present-day complex plate convergence system at the north-eastern boundary of the Indo-Australian Plate.Vertical stress magnitudes, Sv, in the Barrow-Dampier were determined from density and sonic log data. Minimum and maximum horizontal stress magnitudes, Shmin and Shmax, were determined from mini-hydraulic fracture (or modified leak-off) test results. These data suggest that the fault condition of the Wanaea/Cossack area is on the boundary between normal faulting (extension) and strike-slip, i.e. Sv ≈ Shmax > Shmin. However, in other parts of the Barrow-Dampier the evidence suggests a strike-slip fault condition, i.e. Shmax > Sv > Shmin.Given the orientation of the stress field and the fault condition, inferences can be drawn regarding the stability of horizontal wells. Furthermore, experience from vertical wells can be utilized to determine the upper and lower bounds to the mud-weight envelope as functions of deviation and wellbore orientation. Since a horizontal well will see Sv and a horizontal stress, stress anisotropy around a wellbore in the Wanaea/Cossack area (and hence wellbore instability) will be minimized by drilling in the Shmin direction i.e. 010°–030°N.

Sign in / Sign up

Export Citation Format

Share Document