The Role of Calcining and Basal Fluidization in the Long Runout of Carbonate Slides: An Example from the Heart Mountain Slide Block, Wyoming and Montana, U.S.A.

Anders, Mark H.; Fouke, Bruce W.; Zerkle, Aubrey L.; Tavarnelli, Enrico; Álvarez, Walter; Harlow, George E.

doi:10.1086/656383

Cited by 30 publications

(41 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Evidence for multiple slip events, in the form of clasts of breccia within younger breccia, has been presented previously, including by researchers who interpret the slip along the Heart Mountain detachment to be catastrophic (see Anders et al 2010 fig. 4).…”

Section: Discussionmentioning

confidence: 85%

“…1) Feeley and Cosca 2003), along with a welldeveloped radial dike swarm and scattered small plutons. Because of these temporal and spatial relations, the elongate allochthon is generally regarded as a sector collapse, generally southeastward toward the Laramide Bighorn basin (e.g., Beutner and Hauge 2009;Anders et al 2010).…”

Section: Heart Mountain Detachment and Extensional Allochthonmentioning

confidence: 99%

“…Below the detachment in the Paleozoic footwall, bedding within the Ordovician Bighorn Dolostone and Cambrian Snowy Range Formation is usually subhorizontal (dips !107), structurally intact, and parallel to the detachment. In some places, the footwall is virtually undeformed below the detachment, maintaining its original form to within a millimeter or less of the fault (e.g., Anders et al 2010). In others, significant deformation has affected the footwall below the fault (see the discussion below).…”

Section: Heart Mountain Detachment and Extensional Allochthonmentioning

confidence: 99%

“…Brecciation occurs at a distance of up to tens of meters above the fault plane. In some places, a tabular, texturally distinct layer ("basal layer" of Anders et al 2010) occurs directly on the fault plane, usually ∼1 mm thick but in one notable locality (White Mountain; fig. 1) ∼3 m thick.…”

Section: Heart Mountain Detachment and Extensional Allochthonmentioning

confidence: 99%

“…Given these facts, any mechanical conception of the Heart Mountain detachment as forming catastrophically has at its disposal a broad palette of extraordinary circumstances affecting an area of thousands of square kilometers (e.g., fluid overpressure, magmatic devolatilization, seismic accelerations, bolide impact) that need to operate only for as little as a few seconds prior to emplacement rather than a million years or more (e.g., Hughes 1970;Pierce 1973Pierce , 1980Voight 1973;Melosh 1983;Sales 1983;Beutner and Gerbi 2005;Aharonov and Anders 2006;Craddock et al 2009Craddock et al , 2012Anders et al 2010Anders et al , 2013. The gradual emplacement hypothesis, on the other hand, Figure 2.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Episodic Dissolution, Precipitation, and Slip along the Heart Mountain Detachment, Wyoming

Swanson

Wernicke

Hauge³

2016

The Journal of Geology

View full text Add to dashboard Cite

A B S T R A C TThe Heart Mountain allochthon is among the largest landslide masses in the rock record. The basal fault, the Heart Mountain detachment, is an archetype for the mechanical enigma of brittle fracture and subsequent frictional slip on low-angle faults, both of which appear to occur at ratios of shear stress to normal stress far below those predicted by laboratory experiments. The location of the detachment near the base of thick cratonic carbonates, rather than within subjacent shales, is particularly enigmatic for frictional slip. A broad array of potential mechanisms for failure on this rootless fault have been proposed, the majority of which invoke single-event, catastrophic emplacement of the allochthon. Here, we present field, petrographic, and geochemical evidence for multiple slip events, including crosscutting clastic dikes and multiple brecciation and veining events. Cataclasites along the fault show abundant evidence of pressure solution creep. Banded grains, which have been cited as evidence for catastrophic emplacement, are associated with stylolitic surfaces and alteration textures that suggest formation through the relatively slow processes of dissolution and chemical alteration rather than dynamic suspension in a fluid. Temperatures of formation of faultrelated rocks, as revealed by clumped isotope thermometry, are low and incompatible with models of catastrophic emplacement. We propose that displacement along the gently dipping detachment was initiated near the base of the carbonates as localized patches of viscous yielding, engendered by pressure solution. This yielding, which occurred at very low ratios of shear stress to normal stress, induced local subhorizontal tractions along the base of the allochthon, raising shear stress levels (i.e., locally rotating the stress field) to the point where brittle failure and subsequent slip occurred along the detachment. Iteration of this process over geological time produced the observed multikilometer displacements. This concept does not require conditions and materials that are commonly invoked to resolve the stress paradox for low-angle faults, such as near-lithostatic fluid pressures or relative weakness of phyllosilicates in the brittle regime. Cyclic interaction of viscous creep (here by pressure solution) and brittle failure may occur under any fluid pressure conditions and within any rock type, and as such it may be an attractive mechanism for slip on "misoriented" fault planes in general.

show abstract

Section: Discussionmentioning

confidence: 85%

Section: Heart Mountain Detachment and Extensional Allochthonmentioning

confidence: 99%

Section: Heart Mountain Detachment and Extensional Allochthonmentioning

confidence: 99%

Section: Heart Mountain Detachment and Extensional Allochthonmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Episodic Dissolution, Precipitation, and Slip along the Heart Mountain Detachment, Wyoming

Swanson

Wernicke

Hauge³

2016

The Journal of Geology

View full text Add to dashboard Cite

show abstract

Principal Slip Zones in Limestone: Microstructural Characterization and Implications for the Seismic Cycle (Tre Monti Fault, Central Apennines, Italy)

Smith

Billi

Toro

et al. 2011

Pure Appl. Geophys.

125

View full text Add to dashboard Cite

Earthquakes in central Italy, and in other areas worldwide, often nucleate within and rupture through carbonates in the upper crust. During individual earthquake ruptures, most fault displacement is thought to be accommodated by thin principal slip zones. This study presents detailed microstructural observations of the slip zones of the seismically active Tre Monti normal fault zone. All of the slip zones cut limestone, and geological constraints indicate exhumation from\2 km depth, where ambient temperatures are 100C. Scanning electron microscope observations suggest that the slip zones are composed of 100% calcite. The slip zones of secondary faults in the damage zone contain protocataclastic and cataclastic fabrics that are cross-cut by systematic fracture networks and stylolite dissolution surfaces. The slip zone of the principal fault has much more microstructural complexity, and contains a 2–10 mm thick ultracataclasite that lies immediately beneath the principal slip surface. The ultracataclasite itself is internally zoned; 200–300 lm-thick ultracataclastic sub-layers record extreme localization of slip. Syn-tectonic calcite vein networks spatially associated with the sub-layers suggest fluid involvement in faulting. The ultracataclastic sub-layers preserve compelling microstructural evidence of fluidization, and also contain peculiar rounded grains consisting of a central (often angular) clast wrapped by a laminated outer cortex of ultra-fine-grained calcite. These ‘‘clast-cortex grains’’ closely resemble those produced during layer fluidization in other settings, including the basal detachments of catastrophic landslides and saturated high-velocity friction experiments on clay-bearing gouges. An overprinting foliation is present in the slip zone of the principal fault, and electron backscatter diffraction analyses indicate the presence of a weak calcite crystallographic preferred orientation (CPO) in the fine-grained matrix. The calcite c-axes are systematically inclined in the direction of shear. We suggest that fluidization of ultracataclastic sub-layers and formation of clast-cortex grains within the principal slip zone occurred at high strain rates during propagation of seismic ruptures whereas development of an overprinting CPO occurred by intergranular pressure solution during post-seismic creep. Further work is required to document the range of microstructures in localized slip zones that cross-cut different lithologies, and to compare natural slip zone microstructures with those produced in controlled deformation experiments

show abstract

Assessing the Efficiency of Thermochemical Pressurization in the Jiweishan Rockslide

Deng,

Fan,

Scaringi

et al. 2023

Rock Mech Rock Eng

View full text Add to dashboard Cite

The Role of Calcining and Basal Fluidization in the Long Runout of Carbonate Slides: An Example from the Heart Mountain Slide Block, Wyoming and Montana, U.S.A.

Cited by 30 publications

References 59 publications

Episodic Dissolution, Precipitation, and Slip along the Heart Mountain Detachment, Wyoming

Episodic Dissolution, Precipitation, and Slip along the Heart Mountain Detachment, Wyoming

Principal Slip Zones in Limestone: Microstructural Characterization and Implications for the Seismic Cycle (Tre Monti Fault, Central Apennines, Italy)

Assessing the Efficiency of Thermochemical Pressurization in the Jiweishan Rockslide

Contact Info

Product

Resources

About