Name: kinematic history of a salient-recess junction explored through a combined approach of field data and analog sandbox modeling
Uploaded: 2016-08-05T15:00:00
Description: Watch this Scientific Journal Video about Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling at JoVE.com

We thank Erin Bradley and Liz Cole for their assistance in the field. Field work, thin-section preparation and material for the sandbox model was supported by Franklin &amp; Marshall College's Committee on Grants.

1. Collection of Macroscale Field Data
<ol>
	<li>Before conducting field work, use aerial photographs/topographic maps to identify the overall trend of the mountains (defined by the modern-day ridge crest), transverse zones, faults and other lineations at the macroscale (Figure 2).
	<ol>
		<li>Use similar scale topographic maps and aerial photographs, so that patterns can be directly compared. Use 1:24,000 scale maps and photographs.</li>
	</ol>
	</li>
	<li>Label and highlight macroscale features on th...

<ol>
	<li>Marshak, S., Wilkerson, M. S., Hsui, H. T., KR, M. c. C. l. a. y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+curved+fold-thrust+belts:+Insights+from+simple+physical+and+analytical.">Generation of curved fold-thrust belts: Insights from simple physical and analytical.</a> modelsThrust Tectonics. , 83-92 (1992).</li><li>Mitra, G., S, S. e. n. g. u. p. t. a. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+salients+in+a+fold-and-thrust+belt:+the+effects+of+sedimentary+basin+geometry,+strain+distribution+and+critical+taper.">Evolution of salients in a fold-and-thrust belt: the effects of sedimentary basin geometry, strain distribution and critical taper.</a> Evolution of Geological Structures in Micro- to Macro-scales. , 59-90 (1997).</li><li>Weil, A., Sussman, A., A, S. u. s. s. m. a. n., A, W. e. i. l. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Classifying+curved+orogens+based+on+timing+relationships+between+structural+development+and+vertical+axis+rotations.">Classifying curved orogens based on timing relationships between structural development and vertical axis rotations.</a> Orogenic curvature Geol. Soc. of Am. Special Paper. 383, 205-223 (2004).</li><li>Ismat, Z., Mitra, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Folding+by+cataclastic+flow+at+shallow+crustal+levels+in+the+Canyon+Range,+Sevier+orogenic+belt,+west-Central+Utah.">Folding by cataclastic flow at shallow crustal levels in the Canyon Range, Sevier orogenic belt, west-Central Utah.</a> J. of Struct. Geol. 23 (2-3), 355-378 (2001).</li><li>Tull, J., Holm, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+evolution+of+a+major+Appalachian+salient-recess+junction:+Consequences+of+oblique+collisional+convergence+across+a+continental+margin+transform+fault.">Structural evolution of a major Appalachian salient-recess junction: Consequences of oblique collisional convergence across a continental margin transform fault.</a> Geol. Soc. of Am. Bull. 117 (3), 482-499 (2005).</li><li>Ismat, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Block+supported+cataclastic+flow+within+the+upper+crust.">Block supported cataclastic flow within the upper crust.</a> J. of Struct. Geol. 56, 118-128 (2013).</li><li>Ismat, Z., Toeneboehn, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deformation+along+a+salient-transverse+zone+junction:+An+example+from+the+Leamington+transverse+zone,Utah,+Sevier+fold-thrust+belt+(USA).">Deformation along a salient-transverse zone junction: An example from the Leamington transverse zone,Utah, Sevier fold-thrust belt (USA).</a> J. of Struct. Geol. 75, 60-79 (2015).</li><li>Reed, F. S., Mergner, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Rock+Thin+Sections.">Preparation of Rock Thin Sections.</a> Amer. Mineral. 38, 1184-1203 (1953).</li><li>Underwood, E. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Quantitative Stereology. , (1970).</li><li>Fry, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Random+point+distribution+and+strain+measurement+in+rock.">Random point distribution and strain measurement in rock.</a> Tectonophys. 60 (1), 89-105 (1979).</li><li>McNaught, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimating+uncertainty+in+normalized+Fry+plots+using+a+bootstrap+approach.">Estimating uncertainty in normalized Fry plots using a bootstrap approach.</a> J. of Struct. Geol. 24 (2), 311-322 (2002).</li><li>De Paor, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Interactive+Program+for+Doing+Fry+Strain+Analysis+on+the+Macintosh+Microcomputer.">An Interactive Program for Doing Fry Strain Analysis on the Macintosh Microcomputer.</a> J. of Geol. Ed. 37 (3), 171-180 (1989).</li><li>Ismat, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Folding+kinematics+expressed+in+fracture+patterns:+An+example+from+the+Anti-Atlas+fold-belt,+Morocco.">Folding kinematics expressed in fracture patterns: An example from the Anti-Atlas fold-belt, Morocco.</a> J. of Struct. Geol. 30 (11), 1396-1404 (2008).</li><li>Reches, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Faulting+of+rocks+in+three-dimensional+strain+fields:+II.+Theoretical+analysis.">Faulting of rocks in three-dimensional strain fields: II. Theoretical analysis.</a> Tectonophys. 95 (1-2), 133-156 (1983).</li><li>Reches, Z., Dieterich, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Faulting+of+rocks+in+three+dimensional+strain+fields:+1.+Failure+of+rocks+in+polyaxial,+servo-control+experiments.">Faulting of rocks in three dimensional strain fields: 1. Failure of rocks in polyaxial, servo-control experiments.</a> Tectonophys. 95 (1-2), 111-132 (1983).</li><li>Ismat, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+fracture+porosity+and+permeability+during+folding+by+cataclastic+flow:+Implications+for+syntectonic+fluid+flow.">Evolution of fracture porosity and permeability during folding by cataclastic flow: Implications for syntectonic fluid flow.</a> Rocky Mount. Geol. 47 (2), 133-155 (2012).</li><li>Kwon, S., Mitra, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+kinematic+history+at+an+oblique+ramp,+Leamington+zone,+Sevier+belt,+Utah.">Three-dimensional kinematic history at an oblique ramp, Leamington zone, Sevier belt, Utah.</a> J. of Struct. Geol. 28 (3), 474-493 (2006).</li><li>Casas, A. M., Simon, J. L., Seron, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+deflection+in+a+tectonic+compressional+field:+A+model+for+the+northeastern+Iberian+chain,+Spain.">Stress deflection in a tectonic compressional field: A model for the northeastern Iberian chain, Spain.</a> J. of Geophys. Res. 97, 7183-7192 (1992).</li><li>Apotria, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thrust+sheet+rotation+and+out-of-plane+strains+associated+with+oblique+ramps:+An+example.">Thrust sheet rotation and out-of-plane strains associated with oblique ramps: An example.</a> J. of Struct. Geol. 17 (5), 647-662 (1995).</li><li>Hubbert, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Theory+of+Scale+Models+as+Applied+to+the+Study+of+Geological+Structures.">Theory of Scale Models as Applied to the Study of Geological Structures.</a> Geol. Soc. of Am. Bull. 48 (10), 1459-1520 (1937).</li><li>Sch&#246;pfen, M. P. J., Steyrer, H. P., Koyi, H. A., Mancktelow, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+modeling+of+strike-slip+faults+and+the+self-similar+behavior.">Experimental modeling of strike-slip faults and the self-similar behavior.</a> Tectonic Modeling: A volume in honor of Hans Ramberg Geol. Soc. of Am. Mem. 193, 21-27 (2001).</li><li>Kwon, S., Mitra, G., Sussman, A., Weil, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strain+distribution,+strain+history+and+kinematic+evolution+associated+with+the+formation+of+arcuate+salients+in+fold-thrust+belts:+the+example+of+the+Provo+salient,+Sevier+orogeny,+Utah.">Strain distribution, strain history and kinematic evolution associated with the formation of arcuate salients in fold-thrust belts: the example of the Provo salient, Sevier orogeny, Utah.</a> Orogenic curvature Geol. Soc. of Am. Special Paper. 383, 205-223 (2004).</li><li>Elliott, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+motion+of+thrust+sheets.">The motion of thrust sheets.</a> J. of Geophys. Res. 81, 949-963 (1976).</li></ol>

The Central Utah segment of the Sevier fold-thrust belt, and its northern boundary, the Leamington transverse zone serves as an ideal natural laboratory for studying salient-recess junctions (Figure 1). Along this junction, the transport direction remains constant and the thrust sheets are uninterrupted across the junction, so the only variable is the underlying basement geometry5.
Here, we present a method to analyze this type of salient-recess junction by combinin...

Fold-thrust belts are composed of salients (or segments), where the thrust sheets in adjoining salients are decoupled by recesses or transverse zones1,2,3. The transition from salient to recess may be markedly complex, involving a multifaceted suite of structures, and may hold critical clues to fold-thrust belt development. In this paper, we carefully examine a salient-recess junction, using a combination of multiscale field data and a sandbox model, in order to better understand how deformation can be accommodated within fold-thrust belts.
The junction of the Central Utah segment and the Leamington transverse zone is an ideal natural-laboratory for studying salient-recess junctions for several reasons (Figure 1). First, the rocks exposed within the segment continue, uninterrupted, into the transverse zone4. So, deformation patterns can be tracked continuously, and compared across the junction. Second, the rocks are essentially monomineralic, so variation in fault patterns are not a result of heterogeneities within units, but instead reflect the overall folding and thrusting within the study area4. Third, elastico-frictional mechanisms, such as cataclastic flow, assisted deformation throughout the field area, allowing for direct comparisons of mesoscale fault patterns4. Finally, the overall transport direction remained continuous along the length of the segment and transverse zone; therefore, variations in shortening direction did not influence the preserved deformation patterns4. All of these factors minimize the number of variables that may have affected the deformation along the segment and transverse zone. As a result, we surmise that the preserved structures formed primarily because of a change in the underlying basement geometry5.
<img alt="Figure 3" src="/files/ftp_upload/54318/54318fig1.jpg" /> 
Figure 1. Example of index map. The Sevier fold-thrust belt of western USA, showing major salients, segments, recesses and transverse zones. Figure 2 indicated by boxed area (modified from Ismat and Toeneboehn7). <a href="https://www.jove.com/files/ftp_upload/54318/54318fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Folding and thrusting within the Central Utah segment and Leamington transverse zone, took place at depths &#60; 15 km, i.e., within the elastico-frictional regime, where deformation occurred primarily by outcrop-scale (&#60; 1 m) faults and cataclastic flow4,6. Because transport and folding of the thrust sheet took place primarily by elastico-frictional mechanisms, we predict that a detailed fault analysis can provide further insight into the kinematic history of the Leamington transverse zone and the underlying basement geometry. In order to test this hypothesis, we have collected and analyzed fault patterns preserved in the rocks within the northern portion of the Central Utah segment and throughout the Leamington transverse zone (Figure 2).
<img alt="Figure 3" src="/files/ftp_upload/54318/54318fig2.jpg" /> 
Figure 2. Example of macroscale topographic map. Shaded-relief topographic map of boxed area in Figure 1. The 4 Regions are separated by solid white lines. Bedding contacts between the Proterozoic Caddy Canyon quartzite (PCc), Proterozoic Mutual quartzite (PCm) and Cambrian Tintic quartzite (Ct) are shown. Dashed lines show the trend of the mountains within this area. Site locations are shown with numbered black squares. First-order lineations are shown with solid gray lines (modified from Ismat and Toeneboehn7). <a href="https://www.jove.com/files/ftp_upload/54318/54318fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Sandbox experiments were carried out to compare against, and supplement, the fault data. A push-block sandbox model, with frontal and oblique ramps, was used to assist our analyses of the structures preserved in, and around, the Leamington transverse zone (Figure 3) 7. The objectives of this approach are four-fold: 1) determine if the mesoscale fault patterns are consistent, 2) determine if the sandbox model supports and explains the field data, 3) determine if the sandbox model provides more details on structures that are not observed in the field, and 4) evaluate whether this combined field-experimental method is useful and easy to replicate.
<img alt="Figure 3" src="/files/ftp_upload/54318/54318fig3.jpg" /> 
Figure 3. Example of push-block model. Photograph of empty sandbox model. The southern frontal ramp (SFR), oblique ramp (OR), northern frontal ramp (NFR), and the four Regions (1-4) are labeled (modified from Ismat and Toeneboehn7). <a href="https://www.jove.com/files/ftp_upload/54318/54318fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="0" cellpadding="0" cellspacing="0" width="1362">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:227px;">fiberboard</td>
			<td style="width:140px;">Any</td>
			<td style="width:195px;">NA</td>
			<td style="width:800px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">finishing lacquer</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">epoxy</td>
			<td>Epoxy technology</td>
			<td>Parts A and B: 301-2 2LB</td>
			<td>best if warmed to 80&#186; - 125&#186;. If warming is not possible, it will cure fine, it will just take 1 week, rather than 1 day.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ramp wood-pine</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">painters tape</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">rabbit joints</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">countersunk fasteners</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">sand paper</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">play sand</td>
			<td>Any</td>
			<td>NA</td>
			<td>best if homogenous grain size, ~0.5mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">food coloring</td>
			<td>Any</td>
			<td>NA</td>
			<td>best to use one color and a dark color</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">plastic mesh/grid</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">square cross oins</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">crank screw</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">crank handle</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">sheet metal</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">dividers bars</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
	</tbody>
</table>

kinematic history of a salient-recess junction explored through a combined approach of field data and analog sandbox modeling

Within fold-thrust belts, the junctions between salients and recesses may hold critical clues to the overall kinematic history. The deformation history within these junctions is best preserved in areas where thrust sheets extend from a salient through an adjacent recess. We examine one such junction within the Sevier fold-thrust belt (western United States) along the Leamington transverse zone, northern Utah. Deformation within this junction took place by faulting and cataclastic flow. Here, we describe a protocol that examines these fault patterns to better understand the kinematic history of the field area. Fault data is supplemented by analog sandbox experiments. This study suggests that, in detail, deformation within the overlying thrust sheet may not directly reflect the underlying basement structure. We demonstrate that this combined field-experimental approach is easy, accessible, and may provide more details to the deformation preserved in the crust than other more expensive methods, such as computer modeling. In addition, the sandbox model may help to explain why and how these details formed. This method can be applied throughout fold-thrust belts, where upper-crustal rocks are well preserved. In addition, it can be modified to study any part of the upper crust that has been deformed via elastico-frictional mechanisms. Finally, this combined approach may provide more details as to how fold-thrust belts maintain critical-taper and serve as potential targets for natural resource exploration.

Aerial photographs were used to subdivide the field area into four Regions (1-4), based on the trend of the modern mountain ridge crest (Figure 2). Multi-scale fault data is compared between these four Regions. Assuming that these trend changes reflect the underlying basement geometry, the oblique ramp is positioned within Regions 2 and 3, where the mountains trend oblique to the Sevier fold-thrust belt. Throughout the four Regions, we found that the mesoscale faults pres...

Watch this Scientific Journal Video about Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling at JoVE.com

Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling

Kinematic histories of fold-thrust belts are typically based on careful examinations of high-grade metamorphic rocks within a salient. We provide a novel method of understanding fold-thrust belts by examining salient-recess junctions. We analyze the oft-ignored upper crustal rocks using a combined approach of detailed fault analysis with experimental sandbox modeling.

Within fold-thrust belts, the junctions between salients and recesses may hold critical clues to the overall kinematic history. The deformation history ...

The overall goal of this experiment is to track the deformation of thrust sheets as they move over oblique ramps. This method can help answer key questions in the field, such as how thrust sheets evolve in complex settings. The main advantages of this technique are that it is simple, inexpensive, and can be compared directly to the field data.This video shows how to use a push-block sandbox to replicate micro-scale faults found in the field. Field identification of micro-scale faults is covered in the text protocol, as is the general construction of the sandbox. To load the sandbox, use standard play sand, which is relatively homogeneous, with an average grain size of 5 milimeters.Prepare the sand by dying half of it. First, fill a 5 gallon bucket a quarter full. Then mix in enough black food coloring to make the sand a uniform dark green, which is easily distinguishable from the sand's original color.Upon drying the sand, as described in the text protocol, load the box with alternating layers of colored and uncolored sand, and ensure that each layer's leveled after it is added. The thicknesses of the sand pack that provides the clearest and most reproducible results should be arrived at empirically. This example shows a 3.5 centimeter sand pack with alternating colors every 6 centimeters.Next, gently press a plastic mesh composed of half inch of half inch squares onto the sand to produce a grid indentation. Then, insert square cross pins two inches apart throughout the sand. Next, mount a camera to view the entire sandbox.Now, push the sand with the crank-driven push-block to recreate shortening seen in the field. Move the push-block slowly enough that changes in the sand can be carefully documented. The speed should not affect the results.While pushing the sand, track the deformation by observing the shape changes of the squares, and track the amount of transport and vertical rotation by observing the motion of the pins. Repeat this process until the formed structures resemble those preserved in nature. Once the sandbox results mimic those preserved in nature, collect sample data.First, remove all cross pins from the sand. Then, to make samples, separate in epoxy portions of the deformed sand. This requires pre-cut sheet metal dividers.The bottom edge of the dividers must be made to match the angle of the ramp where the sample is to be taken and must fully extend the length of the ramp. The divider must also be taller than the sand pack. Before using a divider, cover it with painter's tape for easy cleanup.One end of the divider must be closer to control the flow of the epoxy, and the other end of the divider must be open to minimized disturbances to the sand pack. Next, fasten the divider using 1/4 inch by four inch screws, sheets with 3/8 inch diameter aluminum tubing. In this case, two dividers are used.One is placed on the oblique ramp, the other covers the frontal oblique ramp junction. Now, pour warm epoxy over the sand within the divider until no more epoxy can be absorbed, so the sand is fully saturated and will not come apart. After several days of drying, slide the dividers out of the sandbox, then lift the epoxied samples out from the surrounding sand.Using a rock saw, cut the samples perpendicularly and parallel to the strike of the ramps. Then, using permanent marker, highlight the bedding, folds, and faults within the exposed slices. A field study found four adjacent regions, each with mesoscale faults.The faults preserve a deformation fabric, which was penetrative and homogeneous at the mesoscale. The fault patterns were also unique within each region, which supported the macroscale assumption that an oblique ramp underlies regions two and three, and suggested that the conjugate-conjugate fault analysis was reliable. Using a sandbox model, a break was formed that was comparable to the position and orientation of the boundary between regions two and three on the macroscale maps.This supported the notion that the break in the overlying thrust sheet may have formed via a complex interaction of an eastward-moving thrust sheet over an oblique ramp. Analysis of epoxied sandbox samples was also supportive. Samples taken from the frontal ramp region accommodated transport to the east, while samples from the oblique ramp region accommodated transport to the southeast.After watching this video, you should have a good understanding of how to build, run, and modify sandbox models to replicate a specific field area. Once mastered, this technique can be done in one week if performed properly. After its development, this technique paved the way for researchers in the field of structural geology to explore the usefulness of fault data and how these data can be further interpreted with the aid of models.Thanks for watching and good luck with your models.

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Advanced micrometeorological methods have become increasingly important in soil, crop, and environmental sciences. For many scientists without formal training in atmospheric science, these techniques are relatively inaccessible. Surface renewal and other flux measurement methods require an understanding of boundary layer meteorology and extensive training in instrumentation and multiple data management programs. To improve accessibility of these techniques, we describe the underlying theory of surface renewal measurements, demonstrate how to set up a field station for surface renewal with eddy covariance calibration, and utilize our open-source turnkey data logger program to perform flux data acquisition and processing. The new turnkey program returns to the user a simple data table with the corrected fluxes and quality control parameters, and eliminates the need for researchers to shuttle between multiple processing programs to obtain the final flux data. An example of data generated from these measurements demonstrates how crop water use is measured with this technique. The output information is useful to growers for making irrigation decisions in a variety of agricultural ecosystems. These stations are currently deployed in numerous field experiments by researchers in our group and the California Department of Water Resources in the following crops: rice, wine and raisin grape vineyards, alfalfa, almond, walnut, peach, lemon, avocado, and corn.

Surface renewal is a micrometeorological method that is being used increasingly to determine energy fluxes, but its technical complexity makes it inaccessible to a broad audience. We describe the steps needed to set up and calibrate a surface renewal field station, to acquire and process data, and to correctly interpret results.

Advanced micrometeorological methods have become  increasingly important in soil, crop, and environmental sciences.  For many scientists without formal ...

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% fine dust formation within the EU15. But NH3 emissions also mean a considerable loss of nutrients. Many studies on NH3 emission from organic and mineral fertilizer application have been performed in recent decades. Nevertheless, research related to NH3 emissions after application fertilizers is still limited in particular with respect to relationships to emissions, fertilizer type, site conditions and crop growth. Due to the variable response of crops to treatments, effects can only be validated in experimental designs including field replication for statistical testing. The dominating ammonia loss methods yielding quantitative emissions require large field areas, expensive equipment or current supply, which restricts their application in replicated field trials. This protocol describes a new methodology for the measurement of NH3 emissions on many plots linking a simple semi-quantitative measuring method used in all plots, with a quantitative method by simultaneous measurements using both methods on selected plots. As a semi-quantitative measurement method passive samplers are used. The second method is a dynamic chamber method (Dynamic Tube Method) to obtain a transfer quotient, which converts the semi-quantitative losses of the passive sampler to quantitative losses (kg nitrogen ha-1). The principle underlying this approach is that passive samplers placed in a homogeneous experimental field have the same NH3 absorption behavior under identical environmental conditions. Therefore, a transfer co-efficient obtained from single passive samplers can be used to scale the values of all passive samplers used in the same field trial. The method proved valid under a wide range of experimental conditions and is recommended to be used under conditions with bare soil or small canopies (&#60;0.3 m). Results obtained from experiments with taller plants should be treated more carefully.

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Ammonia emissions are a major threat to the environment by eutrophication, soil acidification and fine particle formation and stem mainly from agricultural sources. This method allows ammonia loss measurements in replicated field trials enabling statistical analysis of emissions and of relationships between crop development and emissions.

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% ...

Extracting Metrics for Three-dimensional Root Systems: Volume and Surface Analysis from In-soil X-ray Computed Tomography Data

Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to climate change and crop management. Quantitative size information on roots in their native environment is invaluable for studying root growth and environmental processes involving plants. X-ray computed tomography (XCT) has been demonstrated to be an effective tool for in situ root scanning and analysis. We aimed to develop a costless and efficient tool that approximates the surface and volume of the root regardless of its shape from three-dimensional (3D) tomography data. The root structure of a Prairie dropseed (Sporobolus heterolepis) specimen was imaged using XCT. The root was reconstructed, and the primary root structure was extracted from the data using a combination of licensed and open-source software. An isosurface polygonal mesh was then created for ease of analysis. We have developed the standalone application imeshJ, generated in MATLAB1, to calculate root volume and surface area from the mesh. The outputs of imeshJ are surface area (in mm2) and the volume (in mm3). The process, utilizing a unique combination of tools from imaging to quantitative root analysis, is described. A combination of XCT and open-source software proved to be a powerful combination to noninvasively image plant root samples, segment root data, and extract quantitative information from the 3D data. This methodology of processing 3D data should be applicable to other material/sample systems where there is connectivity between components of similar X-ray attenuation and difficulties arise with segmentation.

A methodology for obtaining visual and quantitative root structure information from X-ray computed tomography data acquired in-soil is presented.

Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to ...

Modification and Application of a Leaf Blower-vac for Field Sampling of Arthropods

Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as numbers per standardized sampling area. The sampling efficiency depends critically on the sampling duration. In a mature rice crop, a two-minute sampling in an enclosure of 0.13 m2 yields more than 90% of the arthropod population. The device also allows sampling of arthropods dwelling on the water surface or the soil in rice paddies, but it is not suitable for sampling fast flying insects, such as predatory Odonata or larger hymenopterous parasitoids. The modified blower-vac is simple to construct, and cheaper and easier to handle than traditional suction sampling devices, such as D-vac. The low cost makes the modified blower-vac also accessible to researchers in developing countries.

Assessment of arthropod abundance in crops is critical for investigating population dynamics and species interactions. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropods in rice.

Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the ...

Reliable Method for Assessing Seed Germination, Dormancy, and Mortality under Field Conditions

We describe techniques for approximating seed bank dynamics over time using Helianthus annuus as an example study species. Strips of permeable polyester fabric and glue can be folded and glued to construct a strip of compartments that house seeds and identifying information, while allowing contact with soil leachate, water, microorganisms, and ambient temperature. Strips may be constructed with a wide range of compartment numbers and sizes and allow the researcher to house a variety of genotypes within a single species, different species, or seeds that have experienced different treatments. As opposed to individual seed packets, strips are more easily retrieved as a unit. While replicate packets can be included within a strip, different strips can act as blocks or can be retrieved at different times for observation of seed behavior over time. We used a high temperature glue gun to delineate compartments and sealed the strips once the seed and tags identifying block and removal times were inserted. The seed strips were then buried in the field at the desired depth, with the location marked for later removal. Burrowing animal predators were effectively excluded by use of a covering of metal mesh hardware cloth on the soil surface. After the selected time interval for burial, strips were dug up and seeds were assessed for germination, dormancy and mortality. While clearly dead seeds can often be distinguished from ungerminated living ones by eye, dormant seeds were conclusively identified using a standard Tetrazolium chloride colorimetric test for seed viability.

Here we present a protocol for assessing seed survivorship, germination and dormancy under field conditions using buried, labeled seed strips and tetrazolium chloride (TZ) viability testing.

We describe techniques for approximating seed bank dynamics over time using Helianthus annuus as an example study species. Strips of permeable polyester ...

Field Experiments of Pollination Ecology: The Case of Lycoris sanguinea var. sanguinea

Plant-pollinator interactions have been studied for approximately one hundred years. During that time, many field methods have been developed to clarify the pollination effectiveness of each pollinator for visited flowers. Pollinator observations have been one of the most common methods to identify pollinators, and bagging and cage experiments have been conducted to show the effectiveness of specific pollinators. In a previous study of Lycoris sanguinea var. sanguinea, its effective pollinators, the visitation frequencies of each floral visitor, and its reproductive strategies were not identified. This study reports the observation that small bees visited flowers that were partially opened (breaking buds). To the best of our knowledge, this phenomenon has not been reported previously. Further, this study investigates the hypothesis that small bees can pollinate at that flowering stage. This study demonstrates the basic methods of field experiments in pollination ecology using L. sanguinea var. sanguinea. Pollinator observations and digital video showed the visitation frequencies of each floral visitor. Bagging and cage experiments revealed that these flowers could be pollinated fully and that breaking-bud pollination could be important for the pollination of this plant species. The advantages and disadvantages of each method are discussed, and recent developments, including laboratory experiments, are described.

Field Experiments of Pollination Ecology: The Case of Lycoris sanguinea var. sanguinea

To reveal the pollinator effectiveness of a given plant species, multiple methods of field experiments have been developed. This study demonstrates the basic methods of field experiments for pollination ecology using the case study of Lycoris sanguinea var. sanguinea and the novel pollination mechanism, breaking-bud pollination.

Plant-pollinator interactions have been studied for approximately one hundred years. During that time, many field methods have been developed to clarify ...

Use of a Filter Cartridge for Filtration of Water Samples and Extraction of Environmental DNA

Recent studies demonstrated the use of environmental DNA (eDNA) from fishes to be appropriate as a non-invasive monitoring tool. Most of these studies employed disk fiber filters to collect eDNA from water samples, although a number of microbial studies in aquatic environments have employed filter cartridges, because the cartridge has the advantage of accommodating large water volumes and of overall ease of use. Here we provide a protocol for filtration of water samples using the filter cartridge and extraction of eDNA from the filter without having to cut open the housing. The main portions of this protocol consists of 1) filtration of water samples (water volumes &#8804;4 L or &gt;4 L); (2) extraction of DNA on the filter using a roller shaker placed in a preheated incubator; and (3) purification of DNA using a commercial kit. With the use of this and previously-used protocols, we perform metabarcoding analysis of eDNA taken from a huge aquarium tank (7,500 m3) with known species composition, and show the number of detected species per library from the two protocols as the representative results. This protocol has been developed for metabarcoding eDNA from fishes, but is also applicable to eDNA from other organisms.

We describe a protocol for filtration of water samples with a filter cartridge and extraction of environmental DNA (eDNA) without having to cut open the housing to remove the filter. This protocol is developed for metabarcoding eDNA from fishes, but is also applicable to eDNA from other organisms.

Recent studies demonstrated the use of environmental DNA (eDNA) from fishes to be appropriate as a non-invasive monitoring tool. Most of these studies ...

Development of Metarhizium anisopliae as a Mycoinsecticide: From Isolation to Field Performance

A major concern when developing commercial mycoinsecticides is the kill speed compared to that of chemical insecticides. Therefore, isolation and screening for the selection of a fast-acting, highly virulent entomopathogenic fungus are important steps. Entomopathogenic fungi, such as Metarhizium, Beauveria, and Nomurea, which act by contact, are better suited than Bacillus thuringiensis or nucleopolyhedrosis virus (NPV), which must be ingested by the insect pest. In the present work, we isolated 68 Metarhizium strains from infected insects using a soil dilution and bait method. The isolates were identified by the amplification and sequencing of the ITS1-5.8S-ITS2 and 26S rDNA region. The most virulent strain of Metarhizium anisopliae was selected based on the median lethal concentration (LC50) and time (LT50) obtained in insect bioassays against III-instar larvae of Helicoverpa armigera. The mass production of spores by the selected strain was carried out with solid-state fermentation (SSF) using rice as a substrate for 14 days. Spores were extracted from the sporulated biomass using 0.1% tween-80, and different formulations of the spores were prepared. Field trials of the formulations for the control of an H. armigera infestation in pigeon peas were carried out by randomized block design. The infestation control levels obtained with oil and aqueous formulations (78.0% and 70.9%, respectively) were better than the 63.4% obtained with chemical pesticide.

Development of Metarhizium anisopliae as a Mycoinsecticide: From Isolation to Field Performance

Here, we report the different stages involved in the knowledge-based development of an effective mycoinsecticide, including the isolation, identification, screening, and selection of the "best-fit" entomopathogenic fungus, Metarhizium anisopliae, for the control of insect pests in agriculture.

A major concern when developing commercial mycoinsecticides is the kill speed compared to that of chemical insecticides. Therefore, isolation and ...

Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas

Electrostatic dust transport has been hypothesized to explain a number of observations of unusual planetary phenomena. Here, it is demonstrated using three recently developed experiments in which dust particles are exposed to thermal plasma with beam electrons, beam electrons only, or ultraviolet (UV) radiation only. The UV light source has a narrow bandwidth in wavelength centered at 172 nm. The beam electrons with the energy of 120 eV are created with a negatively biased hot filament. When the vacuum chamber is filled with the argon gas, a thermal plasma is created in addition to the electron beam. Insulating dust particles of a few tens of microns in diameter are used in the experiments. Dust particles are recorded to be lofted to a height up to a few centimeters with a launch speed up to 1 m/s. These experiments demonstrate that photo and/or secondary electron emission from a dusty surface changes the charging mechanism of dust particles. According to the recently developed &#34;patched charge model&#34;, the emitted electrons can be re-absorbed inside microcavities between neighboring dust particles below the surface, causing the accumulation of enhanced negative charges on the surrounding dust particles. The repulsive forces between these negatively charged particles may be large enough to mobilize and lift them off the surface. These experiments present the advanced understanding of dust charging and transport on dusty surfaces, and laid a foundation for future investigations of its role in the surface evolution of airless planetary bodies.

Dust charging and mobilization is demonstrated in three experiments with exposure to thermal plasma with beam electrons, beam electrons only, or ultraviolet (UV) radiation only. These experiments present the advanced understanding of electrostatic dust transport and its role in shaping the surfaces of airless planetary bodies.

Electrostatic dust transport has been hypothesized to explain a number of observations of unusual planetary phenomena. Here, it is demonstrated using ...

A Video Surveillance System to Monitor Breeding Colonies of Common Terns (Sterna Hirundo)

Many waterbird populations have faced declines over the last century, including the common tern (Sterna hirundo), a waterbird species with a widespread breeding distribution, that has been recently listed as endangered in some habitats of its range. Waterbird monitoring programs exist to track populations through time; however, some of the more intensive approaches require entering colonies and can be disruptive to nesting populations. This paper describes a protocol that utilizes a minimally invasive surveillance system to continuously monitor common tern nesting behavior in typical ground-nesting colonies. The video monitoring system utilizes wireless cameras focused on individual nests as well as over the colony as a whole, and allows for observation without entering the colony. The video system is powered with several 12 V car batteries that are continuously recharged using solar panels. Footage is recorded using a digital video recorder (DVR) connected to a hard drive, which can be replaced when full. The DVR may be placed outside of the colony to reduce disturbance. In this study, 3,624 h of footage recorded over 63 days in weather conditions ranging from 12.8 &#176;C to 35.0 &#176;C produced 3,006 h (83%) of usable behavioral data. The types of data retrieved from the recorded video can vary; we used it to detect external disturbances and measure nesting behavior during incubation. Although the protocol detailed here was designed for ground-nesting waterbirds, the principal system could easily be modified to accommodate alternative scenarios, such as colonial arboreal nesting species, making it widely applicable to a variety of research needs.

A Video Surveillance System to Monitor Breeding Colonies of Common Terns Sterna Hirundo

This paper describes a protocol that uses a remote video monitoring surveillance system to continuously monitor breeding colonies of ground-nesting waterbirds. The system includes five cameras monitoring individual nests and one camera monitoring the colony as a whole, and is powered by car batteries that are recharged via solar panels.

Many waterbird populations have faced declines over the last century, including the common tern (Sterna hirundo), a waterbird species with a widespread ...