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annular trough

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Series: GSA Special Papers
Published: 01 January 2007
DOI: 10.1130/2008.2437(06)
... wave excavated a complex transient crater in the target and produced shock metamorphism, melt, ejecta, and an ejecta curtain; the upper part of the target sedimentary section was removed from the inner part of the annular trough adjacent to the transient crater by spallation at the sediment-water...
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Journal Article
Journal: Geology
Published: 01 December 1978
Geology (1978) 6 (12): 716-720.
... craters 1 to 6 km across (some with a central mound and annular trough) or as elongate irregular troughs as much as 6 × 30 km. The patches are interpreted as karst-like areas of collapse breccia (incorporating Messinian evaporites and Pliocene-Quaternary sediments) above surfaces of submarine salt...
Series: GSA Special Papers
Published: 29 November 2018
DOI: 10.1130/2018.2537
EISBN: 9780813795379
... of impact deformation is primarily limited to the target’s sediment layer. This part of the Chesapeake Bay impact structure often has been called the “annular trough,” but it also has been called the “brim” ( Figs. 2 and 3 ). The latter term derives from the shape of the entire Chesapeake Bay impact...
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Journal Article
Published: 02 May 2017
Geological Magazine (2018) 155 (6): 1330-1350.
...MARTIN SCHMIEDER; BARRY J. SHAULIS; THOMAS J. LAPEN; DAVID A. KRING Abstract This work presents a systematic study of zircon and apatite in melt-bearing impactites from the annular trough of the ~180 km and ~66.04 Ma Chicxulub impact crater, Yucatán, Mexico, using in situ laser ablation...
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Journal Article
Journal: Geosphere
Published: 01 February 2015
Geosphere (2015) 11 (1): 123-143.
... that we interpret as the post-impact legacy of the Alamo crater. Together with isopach and lithostratigraphic trends in the underlying Alamo Breccia Member, a new map of the Alamo crater is presented showing the eastern outer rim fault and the annular trough. Size estimates were made using the newly...
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Series: GSA Special Papers
Published: 01 September 2010
DOI: 10.1130/2010.2465(19)
... km to the east, lies wholly within the annular trough of the crater. The Potomac Formation in the Watkins School core is not noticeably impact disrupted. The lower part of crater unit A in the Langley core represents stratigraphically lower, but similarly undeformed material. The Exmore Formation...
Series: GSA Special Papers
Published: 01 January 2009
DOI: 10.1130/2009.2458(27)
... the surrounding seafloor, found to be dominant at Langley, and slumped material that covered the annular trough and basement crater, found to be dominant at Eyreville. Eyreville shows a higher content of crystalline clasts than Langley. There is equivocal evidence for an anti-resurge from a collapsing central...
Series: GSA Special Papers
Published: 01 January 2009
DOI: 10.1130/2009.2458(28)
... the sediments above 618.2 m. Calcareous nannofossil and dino-flagellate data from this interval suggest that the earliest arriving resurge from the west contained little or no Cretaceous marine input, but later resurge pulses mined Cretaceous sediments east of the Watkins core in the annular trough...
Series: GSA Special Papers
Published: 01 January 2009
DOI: 10.1130/2009.2458(34)
... The Eyreville and Exmore, Virginia, core holes were drilled in the inner basin and annular trough, respectively, of the Chesapeake Bay impact structure, and they allow us to evaluate sequence deposition in an impact crater. We provide new high-resolution geochronologic (<1 Ma) and sequence...
Series: GSA Special Papers
Published: 01 January 2009
DOI: 10.1130/2009.2458(38)
... record a pre-impact (Paleozoic?) metamorphic event. Previously published maturity data in the annular trough indicate no thermal effect there from impact-related processes. ...
Journal Article
Published: 01 August 2008
Bulletin of the Seismological Society of America (2008) 98 (4): 2022-2032.
... and sediment-guided P waves in Late Cretaceous and Tertiary sediments within the annular trough of the Late Eocene Chesapeake Bay impact structure. The estimates of Q for the frequency range of 10–150 Hz are from 75 to 100, with the best estimate of 80 based on multichannel stacking of spectral ratios from...
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Journal Article
Journal: Geology
Published: 01 January 2006
Geology (2006) 34 (1): 9-12.
...Cristiano Lana; Rafael Romano; Uwe Reimold; Joao Hippertt Abstract The 40-km-wide Araguainha impact structure in central Brazil provides extensive outcrops to study the structural evolution of all parts of a complex crater, including the central uplift, annular trough, and crater rim. While most...
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Series: GSA Special Papers
Published: 01 January 2005
DOI: 10.1130/0-8137-2384-1.147
... Four new coreholes in the western annular trough of the buried, late Eocene Chesapeake Bay impact structure provide samples of shocked minerals, cataclastic rocks, possible impact melt, mixed sediments, and damaged microfossils. Parautochthonous Cretaceous sediments show an upward increase...
Series: GSA Special Papers
Published: 01 January 1990
DOI: 10.1130/SPE247-p301
... of an appropriate crater form (shallow, rootless structure comprising a central uplift, annular trough, and raised rim), downward and outward attenuation of shock pressures and attendant deformation, characteristic breccia formations, and impact melts composed of near-surface lithologies and containing evidence...
Journal Article
Published: 01 July 2002
Bulletin de la Société Géologique de France (2002) 173 (4): 317-335.
... structures, revealed by hydrographical anomalies, illustrate halokinetic events during the Quaternary. Then the detailed study of the Geaune dome shows a neotectonic phenomenon dating from the Mio-Pliocene. The radial annular drainage pattern of this structure is guided by recurrent faulting during...
Journal Article
Journal: GSA Bulletin
Published: 01 March 2001
GSA Bulletin (2001) 113 (3): 333-345.
...Jon E. Spencer Abstract Hundreds of circular features on Venus known as coronae are characterized by annular fractures and commonly associated radial fractures and lava flows. Coronae are thought to have been produced by buoyant mantle diapirs that flatten and spread at the base of the lithosphere...
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Journal Article
Published: 01 April 2015
American Mineralogist (2015) 100 (4): 681-695.
..., scanning electron microscope, and electron microprobe. All species have two types of biomineral structures: an inner skeleton and sclerites that are small grains of Mg-calcite found in the living tissues surrounding the skeleton. All skeletons display a central core surrounded by an annular domain...
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Journal Article
Journal: GSA Bulletin
Published: 01 September 1955
GSA Bulletin (1955) 66 (9): 1149-1198.
.... The zones follow great circles for most of their lengths, and all are roughly parallel. Topography within the fracture zones is characterized by great seamounts, deep narrow troughs, asymmetrical ridges, and escarpments. Two escarpments are about 1 mile high and more than 1000 miles long. Two fracture zones...
Journal Article
Published: 01 September 1976
Canadian Journal of Earth Sciences (1976) 13 (9): 1301-1309.
...H. C. Halls; R. A. F. Grieve Abstract Shock metamorphic effects in samples from the Slate Islands, Lake Superior (48°40' N, 87°00' W) suggest that the islands are part of a meteorite impact structure. The islands form the central uplift of a complex crater and are ringed by a submerged trough...
Journal Article
Journal: GSA Bulletin
Published: 01 September 2007
GSA Bulletin (2007) 119 (9-10): 1135-1150.
... representing an annular trough. Outcrops are relatively less abundant than those of the Furnas Formation, being mainly observed along the Araguaia River and tributaries that dry out during the winter season. The Ponta Grossa consists of an iron-rich silt-stone intercalated with fine-grained sandstone and thin...
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