Publications
130 results found
Rampe EB, Ming DW, Blake DF, et al., 2017, Mineralogy of an ancient lacustrine mudstone succession from the Murray formation, Gale crater, Mars, EARTH AND PLANETARY SCIENCE LETTERS, Vol: 471, Pages: 172-185, ISSN: 0012-821X
The Mars Science Laboratory Curiosity rover has been traversing strata at the base of Aeolis Mons (informally known as Mount Sharp) since September 2014. The Murray formation makes up the lowest exposed strata of the Mount Sharp group and is composed primarily of finely laminated lacustrine mudstone intercalated with rare crossbedded sandstone that is prodeltaic or fluvial in origin. We report on the first three drilled samples from the Murray formation, measured in the Pahrump Hills section. Rietveld refinements and FULLPAT full pattern fitting analyses of X-ray diffraction patterns measured by the MSL CheMin instrument provide mineral abundances, refined unit-cell parameters for major phases giving crystal chemistry, and abundances of X-ray amorphous materials. Our results from the samples measured at the Pahrump Hills and previously published results on the Buckskin sample measured from the Marias Pass section stratigraphically above Pahrump Hills show stratigraphic variations in the mineralogy; phyllosilicates, hematite, jarosite, and pyroxene are most abundant at the base of the Pahrump Hills, and crystalline and amorphous silica and magnetite become prevalent higher in the succession. Some trace element abundances measured by APXS also show stratigraphic trends; Zn and Ni are highly enriched with respect to average Mars crust at the base of the Pahrump Hills (by 7.7 and 3.7 times, respectively), and gradually decrease in abundance in stratigraphically higher regions near Marias Pass, where they are depleted with respect to average Mars crust (by more than an order of magnitude in some targets). The Mn stratigraphic trend is analogous to Zn and Ni, however, Mn abundances are close to those of average Mars crust at the base of Pahrump Hills, rather than being enriched, and Mn becomes increasingly depleted moving upsection. Minerals at the base of the Pahrump Hills, in particular jarosite and hematite, as well as enrichments in Zn, Ni, and Mn, are products of aci
Morgan LE, Munk M, Davidheiser-Kroll B, et al., 2017, Instrumentation Development for In Situ 40Ar/39Ar Planetary Geochronology, Geostandards and Geoanalytical Research, Vol: 41, Pages: 381-396, ISSN: 1639-4488
The chronology of the Solar System, particularly the timing of formation of extra-terrestrial bodies and their features, is an outstanding problem in planetary science. Although various chronological methods for in situ geochronology have been proposed (e.g., Rb-Sr, K-Ar), and even applied (K-Ar), the reliability, accuracy, and applicability of the 40Ar/39Ar method makes it by far the most desirable chronometer for dating extra-terrestrial bodies. The method however relies on the neutron irradiation of samples, and thus a neutron source. Herein, we discuss the challenges and feasibility of deploying a passive neutron source to planetary surfaces for the in situ application of the 40Ar/39Ar chronometer. Requirements in generating and shielding neutrons, as well as analysing samples are described, along with an exploration of limitations such as mass, power and cost. Two potential solutions for the in situ extra-terrestrial deployment of the 40Ar/39Ar method are presented. Although this represents a challenging task, developing the technology to apply the 40Ar/39Ar method on planetary surfaces would represent a major advance towards constraining the timescale of solar system formation and evolution.
Gupta S, Collier JS, Garcia-Moreno D, et al., 2017, Two-stage opening of the Dover Strait and the origin of island Britain, Nature Communications, Vol: 8, ISSN: 2041-1723
Late Quaternary separation of Britain from mainland Europe is considered to be a consequence of spillover of a large proglacial lake in the Southern North Sea basin. Lake spillover is inferred to have caused breaching of a rock ridge at the Dover Strait, although this hypothesis remains untested. Here we show that opening of the Strait involved at least two major episodes of erosion. Sub-bottom records reveal a remarkable set of sediment-infilled depressions that are deeply incised into bedrock that we interpret as giant plunge pools. These support a model of initial erosion of the Dover Strait by lake overspill, plunge pool erosion by waterfalls and subsequent dam breaching. Cross-cutting of these landforms by a prominent bedrock-eroded valley that is characterised by features associated with catastrophic flooding indicates final breaching of the Strait by high-magnitude flows. These events set-up conditions for island Britain during sea-level highstands and caused large-scale re-routing of NW European drainage.
Rice MS, Gupta S, Treiman AH, et al., 2017, Geologic overview of the Mars Science Laboratory rover mission at the Kimberley, Gale crater, Mars, Journal of Geophysical Research: Planets, Vol: 122, Pages: 2-20, ISSN: 2169-9097
The Mars Science Laboratory (MSL) Curiosity rover completed a detailed investigation at the Kimberley waypoint within Gale crater from sols 571–634 using its full science instrument payload. From orbital images examined early in the Curiosity mission, the Kimberley region had been identified as a high-priority science target based on its clear stratigraphic relationships in a layered sedimentary sequence that had been exposed by differential erosion. Observations of the stratigraphic sequence at the Kimberley made by Curiosity are consistent with deposition in a prograding, fluvio-deltaic system during the late Noachian to early Hesperian, prior to the existence of most of Mount Sharp. Geochemical and mineralogic analyses suggest that sediment deposition likely took place under cold conditions with relatively low water-to-rock ratios. Based on elevated K2O abundances throughout the Kimberley formation, an alkali feldspar protolith is likely one of several igneous sources from which the sediments were derived. After deposition, the rocks underwent multiple episodes of diagenetic alteration with different aqueous chemistries and redox conditions, as evidenced by the presence of Ca-sulfate veins, Mn-oxide fracture fills, and erosion-resistant nodules. More recently, the Kimberley has been subject to significant aeolian abrasion and removal of sediments to create modern topography that slopes away from Mount Sharp, a process that has continued to the present day.
jordan OD, Gupta S, Hampson GJ, et al., 2016, Preserved stratigraphic architecture and evolution of a net-transgressive mixed wave- and tide-influenced coastal system: Cliff House Sandstone, northwestern New Mexico, USA, Journal of Sedimentary Research, Vol: 86, Pages: 1399-1424, ISSN: 1527-1404
The Cretaceous Cliff House Sandstone comprises a thick (400 m) net-transgressive succession representing a mixed wave- and tide-influenced shallow-marine system that migrated episodically landwards. This study examines the youngest part (middle Campanian) of the Cliff House Sandstone, exposed in Chaco Cultural Natural Historical Park, northwest New Mexico, U.S.A. Detailed mapping of facies architecture between a three-dimensional network of measured sections has allowed the character, geometry, and distribution of key stratigraphic surfaces and stratal units to be reconstructed. Upward-shallowing facies successions (parasequences) are separated by laterally extensive transgressive erosion (ravinement) surfaces cut by both wave and tide processes. Preservation of facies tracts in each parasequence is controlled by the depth of erosion and migration trajectory of the overlying ravinement surfaces. In most parasequences, there is no preservation of the proximal wave-dominated facies tracts (foreshore, upper-shoreface), resulting in thin (4–7 m) top-truncated packages. Four distinct shallow marine tongues (parasequence sets) have been identified, consisting of ten parasequences with a total stratigraphic thickness of ~ 100 m. Each tongue records an episode of complex shoreline migration history (multiple regressive–transgressive phases) in an overall net-transgressive system. The ravinement surfaces provide a stratigraphic framework in which to understand partitioning of tide- and wave-dominated deposits in a net-transgressive system, and a model is presented to account for the sediment distribution and stratigraphic architecture observed in each parasequence. Despite a complex internal architecture, parasequences exhibit a predictable pattern which can be related to the regressive and transgressive phases of deposition. Preservation of wave-dominated facies tracts is associated with shoreline regression, while tide-dominated facies tracts are interpreted to
Schieber J, Bish D, Coleman M, et al., 2016, Encounters with an unearthly mudstone: Understanding thefirst mudstone found on Mars, Sedimentology, Vol: 64, Pages: 311-358, ISSN: 1365-3091
The Sheepbed mudstone forms the base of the strata examined by the Curiosity rover in Gale Crater on Mars, and is the first bona fide mudstone known on another planet. From images and associated data, this contribution proposes a holistic interpretation of depositional regime, diagenesis and burial history. A lake basin probably received sediment pulses from alluvial fans. Bed cross-sections show millimetre to centimetre-scale layering due to distal pulses of fluvial sediment injections (fine-grained hyperpycnites), fall-out from river plumes, and some aeolian supply. Diagenetic features include mineralized synaeresis cracks and millimetre-scale nodules, as well as stratiform cementation. Clay minerals were initially considered due to in situ alteration, but bulk rock chemistry and mineralogy suggests that sediments were derived from variably weathered source rocks that probably contained pre-existing clay minerals. X-ray diffraction analyses show contrasting clay mineralogy in closely spaced samples, consistent with at least partial detrital supply of clay minerals. A significant (ca 30 wt%) amorphous component is consistent with little post-depositional alteration. Theoretical modelling of diagenetic reactions, as well as kinetic considerations, suggest that the bulk of diagenetic clay mineral formation occurred comparatively late in diagenesis. Diagenetic features (synaeresis cracks and nodules) were previously thought to reflect early diagenetic gas formation, but an alternative scenario of synaeresis crack formation via fabric collapse of flocculated clays appears more likely. The observed diagenetic features, such as solid nodules, hollow nodules, matrix cement and ‘raised ridges’ (synaeresis cracks) can be explained with progressive alteration of olivine/glass in conjunction with centrifugal and counter diffusion of reactive species. Anhydrite-filled fractures in the Sheepbed mudstone occurred late in diagenesis when fluid pressures built up to ex
Davis JM, Balme M, Grindrod PM, et al., 2016, Extensive Noachian fluvial systems in Arabia Terra: Implications for early Martian climate, Geology, Vol: 44, Pages: 847-850, ISSN: 1943-2682
Valley networks are some of the strongest lines of evidence for extensive fluvial activity on early (Noachian; >3.7 Ga) Mars. However, their purported absence on certain ancient terrains, such as Arabia Terra, is at variance with patterns of precipitation as predicted by “warm and wet” climate models. This disagreement has contributed to the development of an alternative “icy highlands” scenario, whereby valley networks were formed by the melting of highland ice sheets. Here, we show through regional mapping that Arabia Terra shows evidence for extensive networks of sinuous ridges. We interpret these ridge features as inverted fluvial channels that formed in the Noachian, before being subject to burial and exhumation. The inverted channels developed on extensive aggrading flood plains. As the inverted channels are both sourced in, and traverse across, Arabia Terra, their formation is inconsistent with discrete, localized sources of water, such as meltwater from highland ice sheets. Our results are instead more consistent with an early Mars that supported widespread precipitation and runoff.
Carrapa B, Di Giulio A, Mancin N, et al., 2016, Tectonic significance of Cenozoic exhumation and foreland basin evolution in the Western Alps, TECTONICS, Vol: 35, Pages: 1892-1912, ISSN: 0278-7407
Lapotre MG, Ewing RC, Lamb MP, et al., 2016, Large wind ripples on Mars: a record of atmospheric evolution, Science, Vol: 353, Pages: 55-58, ISSN: 1095-9203
Wind blowing over sand on Earth produces decimeter-wavelength ripples and hundred-meter- to kilometer-wavelength dunes: bedforms of two distinct size modes. Observations from the Mars Science Laboratory Curiosity rover and the Mars Reconnaissance Orbiter reveal that Mars hosts a third stable wind-driven bedform, with meter-scale wavelengths. These bedforms are spatially uniform in size and typically have asymmetric profiles with angle-of-repose lee slopes and sinuous crest lines, making them unlike terrestrial wind ripples. Rather, these structures resemble fluid-drag ripples, which on Earth include water-worked current ripples, but on Mars instead form by wind because of the higher kinematic viscosity of the low-density atmosphere. A reevaluation of the wind-deposited strata in the Burns formation (about 3.7 billion years old or younger) identifies potential wind-drag ripple stratification formed under a thin atmosphere.
Le Deit L, Mangold N, Forni O, et al., 2016, The potassic sedimentary rocks in Gale Crater, Mars, as seen by ChemCam on board Curiosity, Journal of Geophysical Research: Planets, Vol: 121, Pages: 784-804, ISSN: 2169-9100
The Mars Science Laboratory rover Curiosity encountered potassium-rich clastic sedimentary rocks at two sites in Gale Crater, the waypoints Cooperstown and Kimberley. These rocks include several distinct meters thick sedimentary outcrops ranging from fine sandstone to conglomerate, interpreted to record an ancient fluvial or fluvio-deltaic depositional system. From ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) chemical analyses, this suite of sedimentary rocks has an overall mean K2O abundance that is more than 5 times higher than that of the average Martian crust. The combined analysis of ChemCam data with stratigraphic and geographic locations reveals that the mean K2O abundance increases upward through the stratigraphic section. Chemical analyses across each unit can be represented as mixtures of several distinct chemical components, i.e., mineral phases, including K-bearing minerals, mafic silicates, Fe-oxides, and Fe-hydroxide/oxyhydroxides. Possible K-bearing minerals include alkali feldspar (including anorthoclase and sanidine) and K-bearing phyllosilicate such as illite. Mixtures of different source rocks, including a potassium-rich rock located on the rim and walls of Gale Crater, are the likely origin of observed chemical variations within each unit. Physical sorting may have also played a role in the enrichment in K in the Kimberley formation. The occurrence of these potassic sedimentary rocks provides additional evidence for the chemical diversity of the crust exposed at Gale Crater.
Singh A, Paul D, Sinha R, et al., 2016, Reply to the comment on "Geochemistry of buried river sediments from Ghaggar Plains, NW India: Multi-proxy records of variations in provenance, paleoclimate, and paleovegetation patterns in the Late Quaternary" by Singh et al. (2016), Palaeogeography, Palaeoclimatology, Palaeoecology 449 (2016) 85-100, Palaeogeography Palaeoclimatology Palaeoecology, Vol: 455, Pages: 68-70, ISSN: 0031-0182
Yingst RA, Cropper K, Gupta S, et al., 2016, Characteristics of pebble and cobble-sized clasts along the Curiosity rover traverse from sol 100 to 750: Terrain types, potential sources, and transport mechanisms, Icarus, Vol: 280, Pages: 72-92, ISSN: 0019-1035
We combine the results of orbitally-derived morphologic and thermal inertia data with in situ observations of abundance, size, morphologic characteristics, and distribution of pebble- to cobble-sized clasts along the Curiosity rover traverse. Our goals are to characterize rock sources and transport history, and improve our ability to predict upcoming terrain. There are ten clast types, with nine types interpreted as sedimentary rocks. Only Type 3 clasts had morphologies indicative of significant wear through transport; thus, most clast types are indicative of nearby outcrops or prior presence of laterally extensive sedimentary rock layers, consistent with the erosional landscape. A minor component may reflect impact delivery of more distant material. Types 1 and 4 are heavily-cemented sandstones, likely associated with a “caprock” layer. Types 5 and 6 (and possibly 7) are pebble-rich sandstones, with varying amounts of cement leading to varying susceptibility to erosion/wear. Type 3 clasts are rounded pebbles likely transported and deposited alluvially, then worn out of pebbly sandstone/conglomerate. Types 9 and 10 are poorly-sorted sandstones, with Type 9 representing fragments of Square Top-type layers, and Type 10 deriving from basal or other Mt. Sharp layers. Types 2, 8 and 9 are considered exotics.There are few clear links between clast type and terrain surface roughness (particularly in identifying terrain that is challenging for the rover to navigate). Orbital data may provide a reasonable prediction of certain end-member terrains but the complex interplay between variables that contribute to surface characteristics makes discriminating between terrain types from orbital data problematic. Prediction would likely be improved through higher-resolution thermal inertia data.
Stack KM, Edwards CS, Grotzinger JP, et al., 2016, Comparing orbiter and rover image-based mapping of an ancient sedimentary environment, Aeolis Palus, Gale crater, Mars, Icarus, Vol: 280, Pages: 3-21, ISSN: 1090-2643
This study provides the first systematic comparison of orbital facies maps with detailed ground-based geology observations from the Mars Science Laboratory (MSL) Curiosity rover to examine the validity of geologic interpretations derived from orbital image data. Orbital facies maps were constructed for the Darwin, Cooperstown, and Kimberley waypoints visited by the Curiosity rover using High Resolution Imaging Science Experiment (HiRISE) images. These maps, which represent the most detailed orbital analysis of these areas to date, were compared with rover image-based geologic maps and stratigraphic columns derived from Curiosity's Mast Camera (Mastcam) and Mars Hand Lens Imager (MAHLI). Results show that bedrock outcrops can generally be distinguished from unconsolidated surficial deposits in high-resolution orbital images and that orbital facies mapping can be used to recognize geologic contacts between well-exposed bedrock units. However, process-based interpretations derived from orbital image mapping are difficult to infer without known regional context or observable paleogeomorphic indicators, and layer-cake models of stratigraphy derived from orbital maps oversimplify depositional relationships as revealed from a rover perspective. This study also shows that fine-scale orbital image-based mapping of current and future Mars landing sites is essential for optimizing the efficiency and science return of rover surface operations.
Singh A, Paul D, Sinha R, et al., 2016, Geochemistry of buried river sediments from Ghaggar Plains, NW India: Multi-proxy records of variations in provenance, paleoclimate, and paleovegetation patterns in the Late Quaternary, Palaeogeography Palaeoclimatology Palaeoecology, Vol: 449, Pages: 85-100, ISSN: 0031-0182
Van Dijk W, Densmore A, Singh A, et al., 2016, Linking the morphology of fluvial fan systems to aquifer stratigraphy in the Sutlej-Yamuna plain of northwest India, Journal of Geophysical Research, Vol: 121, Pages: 201-222, ISSN: 0148-0227
The Indo-Gangetic foreland basin has some of the highest rates of groundwater extractionin the world, focused in the states of Punjab and Haryana in northwest India. Any assessment of theeffects of extraction on groundwater variation requires understanding of the geometry and sedimentaryarchitecture of the alluvial aquifers, which in turn are set by their geomorphic and depositional setting. Toassess the overall architecture of the aquifer system, we used satellite imagery and digital elevation modelsto map the geomorphology of the Sutlej and Yamuna fan systems, while aquifer geometry was assessedusing 243 wells that extend to ∼200 m depth. Aquifers formed by sandy channel bodies in the subsurfaceof the Sutlej and Yamuna fans have a median thickness of 7 and 6 m, respectively, and follow heavy-tailedthickness distributions. These distributions, along with evidence of persistence in aquifer fractions asdetermined from compensation analysis, indicate persistent reoccupation of channel positions and suggestthat the major aquifers consist of stacked, multistoried channel bodies. The percentage of aquifer material inindividual boreholes decreases down fan, although the exponent on the aquifer body thickness distributionremains similar, indicating that the total number of aquifer bodies decreases down fan but that individualbodies do not thin appreciably, particularly on the Yamuna fan. The interfan area and the fan marginal zonehave thinner aquifers and a lower proportion of aquifer material, even in proximal locations. We concludethat geomorphic setting provides a first-order control on the thickness, geometry, and stacking pattern ofaquifer bodies across this critical region.
Treiman AH, Bish DL, Vaniman DT, et al., 2016, Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X-ray diffraction of the Windjana sample (Kimberley area, Gale Crater), Journal of Geophysical Research: Planets, Vol: 121, Pages: 75-106, ISSN: 2169-9100
The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X-ray diffraction (XRD) in the MSL Curiosity rover. From Rietveld refinements of its XRD pattern, Windjana contains the following: sanidine (21% weight, ~Or95); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (~25%); and percent levels of others including ilmenite, fluorapatite, and bassanite. From mass balance on the Alpha Proton X-ray Spectrometer (APXS) chemical analysis, the amorphous material is Fe rich with nearly no other cations—like ferrihydrite. The Windjana sample shows little alteration and was likely cemented by its magnetite and ferrihydrite. From ChemCam Laser-Induced Breakdown Spectrometer (LIBS) chemical analyses, Windjana is representative of the Dillinger and Mount Remarkable members of the Kimberley formation. LIBS data suggest that the Kimberley sediments include at least three chemical components. The most K-rich targets have 5.6% K2O, ~1.8 times that of Windjana, implying a sediment component with >40% sanidine, e.g., a trachyte. A second component is rich in mafic minerals, with little feldspar (like a shergottite). A third component is richer in plagioclase and in Na2O, and is likely to be basaltic. The K-rich sediment component is consistent with APXS and ChemCam observations of K-rich rocks elsewhere in Gale Crater. The source of this sediment component was likely volcanic. The presence of sediment from many igneous sources, in concert with Curiosity's identifications of other igneous materials (e.g., mugearite), implies that the northern rim of Gale Crater exposes a diverse igneous complex, at least as diverse as that found in similar-age terranes on Earth.
Collier JS, Oggioni F, Gupta S, et al., 2015, Streamlined islands and the English Channel megaflood hypothesis, Global and Planetary Change, Vol: 135, Pages: 190-206, ISSN: 0921-8181
Recognising ice-age catastrophic megafloods is important because they had significant impact on large-scale drainage evolution and patterns of water and sediment movement to the oceans, and likely induced very rapid, short-term effects on climate. It has been previously proposed that a drainage system on the floor of the English Channel was initiated by catastrophic flooding in the Pleistocene but this suggestion has remained controversial. Here we examine this hypothesis through an analysis of key landform features. We use a new compilation of multi- and single-beam bathymetry together with sub-bottom profiler data to establish the internal structure, planform geometry and hence origin of a set of 36 mid-channel islands. Whilst there is evidence of modern-day surficial sediment processes, the majority of the islands can be clearly demonstrated to be formed of bedrock, and are hence erosional remnants rather than depositional features. The islands display classic lemniscate or tear-drop outlines, with elongated tips pointing downstream, typical of streamlined islands formed during high-magnitude water flow. The length-to-width ratio for the entire island population is 3.4 ± 1.3 and the degree-of-elongation or k-value is 3.7 ± 1.4. These values are comparable to streamlined islands in other proven Pleistocene catastrophic flood terrains and are distinctly different to values found in modern-day rivers. The island geometries show a correlation with bedrock type: with those carved from Upper Cretaceous chalk having larger length-to-width ratios (3.2 ± 1.3) than those carved into more mixed Paleogene terrigenous sandstones, siltstones and mudstones (3.0 ± 1.5). We attribute these differences to the former rock unit having a lower skin friction which allowed longer island growth to achieve minimum drag. The Paleogene islands, although less numerous than the Chalk islands, also assume more perfect lemniscate shapes. These lithologies therefore
Grotzinger JP, Gupta S, Malin MC, et al., 2015, Deposition, exhumation, and paleoclimate of an ancient lake deposit, Gale crater, Mars, Science, Vol: 350, Pages: 1-12, ISSN: 0036-8075
The landforms of northern Gale crater on Mars expose thick sequences of sedimentary rocks. Based on images obtained by the Curiosity rover, we interpret these outcrops as evidence for past fluvial, deltaic, and lacustrine environments. Degradation of the crater wall and rim probably supplied these sediments, which advanced inward from the wall, infilling both the crater and an internal lake basin to a thickness of at least 75 meters. This intracrater lake system probably existed intermittently for thousands to millions of years, implying a relatively wet climate that supplied moisture to the crater rim and transported sediment via streams into the lake basin. The deposits in Gale crater were then exhumed, probably by wind-driven erosion, creating Aeolis Mons (Mount Sharp).
Jaumann R, Tirsch D, Hauber E, et al., 2015, Quantifying geological processes on Mars-Results of the high resolution stereo camera (HRSC) on Mars express, PLANETARY AND SPACE SCIENCE, Vol: 112, Pages: 53-97, ISSN: 0032-0633
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- Citations: 18
Garcia-Moreno D, Verbeeck K, Camelbeeck T, et al., 2015, Fault activity in the epicentral area of the 1580 Dover Strait (Pas-de-Calais) earthquake (northwestern Europe), Geophysical Journal International, Vol: 201, Pages: 528-542, ISSN: 1365-246X
On 1580 April 6 one of the most destructive earthquakes of northwestern Europe took placein the Dover Strait (Pas de Calais). The epicentre of this seismic event, the magnitude ofwhich is estimated to have been about 6.0, has been located in the offshore continuationof the North Artois shear zone, a major Variscan tectonic structure that traverses the DoverStrait. The location of this and two other moderate magnitude historical earthquakes in theDover Strait suggests that the North Artois shear zone or some of its fault segments may bepresently active. In order to investigate the possible fault activity in the epicentral area ofthe AD 1580 earthquake, we have gathered a large set of bathymetric and seismic-reflectiondata covering the almost-entire width of the Dover Strait. These data have revealed a broadstructural zone comprising several subparallel WNW–ESE trending faults and folds, some ofthem significantly offsetting the Cretaceous bedrock. The geophysical investigation has alsoshown some indication of possible Quaternary fault activity. However, this activity only appearsto have affected the lowermost layers of the sediment infilling Middle Pleistocene palaeobasins.This indicates that, if these faults have been active since Middle Pleistocene, their slip ratesmust have been very low. Hence, the AD 1580 earthquake appears to be a very infrequentevent in the Dover Strait, representing a good example of the moderate magnitude earthquakesthat sometimes occur in plate interiors on faults with unknown historical seismicity.
Anderson R, Bridges JC, Williams A, et al., 2015, ChemCam results from the Shaler outcrop in Gale crater, Mars, ICARUS, Vol: 249, Pages: 2-21, ISSN: 0019-1035
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- Citations: 50
Mangold N, Forni O, Dromart G, et al., 2015, Chemical variations in Yellowknife Bay formation sedimentary rocks analyzed by ChemCam on board the Curiosity rover on Mars, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 120, Pages: 452-482, ISSN: 2169-9097
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- Citations: 46
Warner NH, Gupta S, Calef F, et al., 2015, Minimum effective area for high resolution crater counting of martian terrains, ICARUS, Vol: 245, Pages: 198-240, ISSN: 0019-1035
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- Citations: 91
Poole W, Muller J-P, Gupta S, et al., 2014, Calibrating Mars Orbiter Laser Altimeter pulse widths at Mars Science Laboratory candidate landing sites, PLANETARY AND SPACE SCIENCE, Vol: 99, Pages: 118-127, ISSN: 0032-0633
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- Citations: 2
Vasavada AR, Grotzinger JP, Arvidson RE, et al., 2014, Overview of the Mars Science Laboratory mission: Bradbury Landing to Yellowknife Bay and beyond, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 119, Pages: 1134-1161, ISSN: 2169-9097
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- Citations: 100
Palucis MC, Dietrich WE, Hayes AG, et al., 2014, The origin and evolution of the Peace Vallis fan system that drains to the <i>Curiosity</i> landing area, Gale Crater, Mars, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 119, Pages: 705-728, ISSN: 2169-9097
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- Citations: 102
Goddard K, Warner NH, Gupta S, et al., 2014, Mechanisms and timescales of fluvial activity at Mojave and other young Martian craters, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 119, Pages: 604-634, ISSN: 2169-9097
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- Citations: 14
Mark C, Gupta S, Carter A, et al., 2014, Rift flank uplift at the Gulf of California: No requirement for asthenospheric upwelling, GEOLOGY, Vol: 42, Pages: 259-262, ISSN: 0091-7613
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- Citations: 24
Vaniman DT, Bish DL, Ming DW, et al., 2014, Mineralogy of a Mudstone at Yellowknife Bay, Gale Crater, Mars, SCIENCE, Vol: 343, ISSN: 0036-8075
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- Citations: 460
Ming DW, Archer PD, Glavin DP, et al., 2014, Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale Crater, Mars, SCIENCE, Vol: 343, ISSN: 0036-8075
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- Citations: 280
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