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spiral troughs

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Journal Article
Journal: Geology
Published: 01 April 2004
Geology (2004) 32 (4): 365–367.
... on Mars. Starting from random initial conditions, the three-dimensional model reproduces spiral waves very similar to those in the north polar ice cap, including secondary features such as gull-wing–shaped troughs, bifurcations, and terminations. These results suggest that eolian processes and ice flow...
FIGURES
Image
Time slice through the Planum Boreum SHARAD 3D volume (a) after (piecewise) 3D downward continuation and (b) (piecewise) 3D Stolt migration. As shown, the time slices span 1152.4 km × 974.7 km. Color indicates radar return power (blue high, red low). Red lines on the left time slice mark locations of inline (vertical) and crossline (horizontal) profiles shown in Figure 9. The imaging processes have focused the surface and subsurface radar returns, clarifying the structural features (most visibly the pervasive spiral troughs) throughout the ice cap. Note that, at this scale, these time slice images are visibly identical, indicating that the downward continuation has accomplished virtually all of the image focusing. Note also that the faint “cross hatching” in the time slices, made especially visible by the color scheme used for display (reds are low power), is due to truncation artifacts from the adjacent downward continued pieces.
Published: 01 January 2017
mark locations of inline (vertical) and crossline (horizontal) profiles shown in Figure 9 . The imaging processes have focused the surface and subsurface radar returns, clarifying the structural features (most visibly the pervasive spiral troughs) throughout the ice cap. Note that, at this scale
Journal Article
Journal: Geology
Published: 01 May 2004
Geology (2004) 32 (5): 384.
... Geological Society of America 2004 How do spiral troughs form on Mars?: Correction. Jon D. Pelletier Geology , v. 32, p. 365–367 (April 2004) Several errors appear in the text of this article. They are: Equation 1 should read rather than The cross product should...
Image
FIGURE 4—Modern traces in association with C. coeca. A) Mucous-lined burrows of Heteromastis filiformis (white arrows) accumulated in a wave-ripple trough. C. coeca trails (black arrows) also in the trough. Round hole near the top of the image is the result of water drainage from the sample tray. B) Delicate, mucous-lined spirals of Paraonis fulgens. C) Similarities between the gastropod (Littorina littorea) trail (white arrow) and the locomotion trail of C. coeca (black arrow).
Published: 01 May 2008
FIGURE 4 —Modern traces in association with C. coeca . A) Mucous-lined burrows of Heteromastis filiformis (white arrows) accumulated in a wave-ripple trough. C. coeca trails (black arrows) also in the trough. Round hole near the top of the image is the result of water drainage from the sample
Book Chapter

Series: SEPM Short Course Notes
Published: 01 January 1984
DOI: 10.2110/scn.84.03.0007
EISBN: 9781565762329
... in detail. Most are elongated either parallel or transverse to the flow. Parallel-to-flow bed forms seem to be a manifestation of spiraling fluid motion, called secondary flow, that is parallel to the main flow and superimposed upon it. The convergent and divergent transverse components of near-bed flow may...
Journal Article
Journal: AAPG Bulletin
Published: 01 April 1973
AAPG Bulletin (1973) 57 (4): 811.
... a complete section from Coniacian to Pleistocene. Faunal and sedimentologic evidence from the cores suggests that deposition was abyssal. The most distinctive biogenic structures are Zoophycus (a spiral web), Teichichnus (a laminated trough), and Chondrites (a regularly branched system). These represent...
Journal Article
Journal: The Leading Edge
Published: 01 January 2017
The Leading Edge (2017) 36 (1): 43–57.
... mark locations of inline (vertical) and crossline (horizontal) profiles shown in Figure 9 . The imaging processes have focused the surface and subsurface radar returns, clarifying the structural features (most visibly the pervasive spiral troughs) throughout the ice cap. Note that, at this scale...
FIGURES | View All (14)
Image
Wiwaxy Peaks Member. (A–D) Highway #1 near Spiral Tunnels. (A) Very thick-bedded compound cross-stratified sandstone package. White lines mark its overall lenticular geometry. (B) Interval composed of very thick-bedded planar and trough cross-stratified sandstone showing bipolar paleocurrent indicators. Person for scale. (C) Portion of very thick-bedded compound cross-stratified sandstone interval showing transition (white arrow) from intercalated very thin- to thin-bedded sandstone and mudstone to medium-bedded cross-stratified sandstone. (D) Coarsening-and thickening-upward amalgamated hummocky cross-stratified sandstone. (E) Very thick-bedded, lenticular, cross-stratified sandstone characterized by bundles, reactivation surfaces (white arrows), mud drapes, and asymptotic foresets which grade to horizontal, rippled bottomsets. Mount Temple above Moraine Lake.
Published: 01 December 2010
Fig. 19. Wiwaxy Peaks Member. (A–D) Highway #1 near Spiral Tunnels. (A) Very thick-bedded compound cross-stratified sandstone package. White lines mark its overall lenticular geometry. (B) Interval composed of very thick-bedded planar and trough cross-stratified sandstone showing bipolar
Journal Article
Published: 01 January 2002
Journal of Foraminiferal Research (2002) 32 (1): 51–56.
... and has little differential value. They regard the Gavelinellidae as part of the Chilostomellacea. Suborder Rotaliina Lankester, 1885 Family Rosalinidae Reiss, 1963 Albertinopsis gen. nov . Discorbis norrisi Mellon and Wall, 1956 . Test free, low trochospiral. Spiral side...
FIGURES
Image
Figure 2. Numerical model results and north-polar topography. A: Shaded-relief image of Martian north-polar ice-cap digital elevation model (DEM) constructed by using Mars Orbiter Laser Altimeter topography. White region north of 88°N indicates region with DEM artifacts. Large-scale close- up indicates examples of gull-wing-shaped troughs, bifurcations, and terminations. Highest elevations are red and lowest elevations are green. B–E: Shaded- relief images of model topography, −h, for (B) t = 10, (C) t = 100, (D) t = 1000, and (E) t = 2000 starting from random initial conditions. Model parameters are L = 100 (length and width of grid, in nondimensional units), κ = 0.3, τi = 0.05, τf = 1 (see text). Model evolution is characterized by spi ral merging and alignment in equator-facing direction. Steady state is eventually reached, as shown in E, with uniformly rotating spirals oriented clockwise or counterclockwise depending on random initial conditions.
Published: 01 April 2004
indicates examples of gull-wing-shaped troughs, bifurcations, and terminations. Highest elevations are red and lowest elevations are green. B–E: Shaded- relief images of model topography, − h , for (B) t = 10, (C) t = 100, (D) t = 1000, and (E) t = 2000 starting from random initial conditions. Model
Journal Article
Journal: PALAIOS
Published: 01 May 2008
PALAIOS (2008) 23 (5): 336–343.
...FIGURE 4 —Modern traces in association with C. coeca . A) Mucous-lined burrows of Heteromastis filiformis (white arrows) accumulated in a wave-ripple trough. C. coeca trails (black arrows) also in the trough. Round hole near the top of the image is the result of water drainage from the sample...
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Journal Article
Journal: Geology
Published: 01 December 2006
Geology (2006) 34 (12): 1057–1060.
... structures such as scratch circles consist of a series of concentric circles ( Jensen et al., 2002 ). Concentric circles and spiral structures can also form in microbial mat grounds due to shrinkage of cohesive material in the troughs of interference ripples, and are common in Precambrian and lower Paleozoic...
FIGURES
Journal Article
Journal: PALAIOS
Published: 01 April 2005
PALAIOS (2005) 20 (2): 192–197.
... the number of fossils in the troughs averages 0–2/10 cm 3 . There is approximately one gastropod for every 20 bivalves, with other taxa rare (1 or 2 for the whole assemblage; Fig. 2 ). The macrofauna consists, in rank order abundance, of bivalves, spiral and planispiral gastropods, and an eurypterid...
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Journal Article
Journal: Geophysics
Published: 23 July 2020
Geophysics (2020) 85 (5): O71–O82.
... spiral structure. The input gather is stacked to create a reference trace, and DTW is performed to determine the shifts that match each of the traces within the gather to the stack. To avoid cycle skipping, a strain limit is placed on the shifts so that they are unable to change too rapidly with time...
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Journal Article
Published: 01 March 2001
Journal of Paleontology (2001) 75 (2): 466–470.
... Group accumulating in a northwest-facing trough that joined to the Blackstone River and Richardson troughs ( Lenz, 1972 ; Norford, 1997 ). In the transitional zone, perhaps no more than one kilometer in width, brachiopods flourished, and trilobites, bryozoans, corals and gastropods were relatively...
FIGURES
Journal Article
Published: 01 May 2008
Journal of Paleontology (2008) 82 (3): 595–603.
... subtidal), sparsely fossiliferous carbonates accumulating on the large platform immediately to the east, southeast, and south of the study area, and deep-water, graptolite-rich shales and calcareous shales of the Road River Group accumulating in a northwest-facing trough that joined to the Blackstone River...
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Journal Article
Published: 01 July 2010
Journal of Foraminiferal Research (2010) 40 (3): 266–282.
..., side view; 9, 10, apertural view. 11–13 Buliminella elegantissima , LC444 ( ex situ ), Urumaco Formation?: 11, side view; 12, 13 apertural view; 14, 15 Uvigerina peregrina gr., LC453, Caujarao Formation, side views. 16, 17 Cassidulina laevigata , LC460, La Vela Formation: 16, spiral view; 17...
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Journal Article
Published: 01 October 2015
Journal of Foraminiferal Research (2015) 45 (4): 344–353.
... foraminifera from CWC ecosystems published so far from the Norwegian shelf (e.g., Joseph et al., 2013 ; Spezzaferri et al., 2013 ; Stalder et al., 2014 ), the Porcupine Seabight and Rockall Trough (e.g., Rüggeberg et al., 2007 ; Margreth et al., 2009 ; Schönfeld et al., 2011 ; Smeulders et al., 2014...
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Journal Article
Published: 01 April 2014
Journal of Foraminiferal Research (2014) 44 (2): 151–176.
... characterized by widening and joining of chamber flaps into an umbilical plug. Protostensioeina n. gen. is proposed to accommodate species characterized by the lack of features typically observed in Stensioeina , such as spiral-side ornamentation consisting of curved, limbate sutures, strongly elevated...
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Journal Article
Journal: PALAIOS
Published: 01 March 2016
PALAIOS (2016) 31 (3): 81–91.
... . Reynolds R.E. Berry D.R. 2008 , Preliminary review of invertebrate fossil localities from the Bouse Formation, Blythe basin, California , in Reynolds R.E. (ed.), Trough to Trough...
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