Laura C. Gregory

• PostDoc Position at University of Leeds

Cosmogenic exposure data can be used to calculate time‐varying fault slip rates on normal faults with exposed bedrock scarps. The method relies on assumptions related to how the scarp is preserved, which should be consistent at multiple locations along the same fault. Previous work commonly relied on cosmogenic data from a single sample locality to...

Plain Language Summary During an earthquake, slip on a fault plane creates discrete offsets at depth and at the surface. The pattern and size of offsets at the surface can help to understand what happened in the earthquake and also leaves a record of each event in the landscape. This record is used to infer past earthquake activity and forecast the...

Two natural mineral separates, labeled CoCal-N and CoFsp-N, have been prepared to serve as intercomparisonmaterial (ICM) for in situ-produced cosmogenic 36Cl and natural chlorine (Clnat) analysis. The sample CoCal-N isderived from calcite crystals in a Namibian lag deposit, while the sample CoFsp-N is derived from a single crystalof alkali-feldspar...

Two natural mineral separates, labeled CoCal-N and CoFsp-N, have been prepared to serve as intercomparison material (ICM) for in situ-produced cosmogenic ³⁶Cl and natural chlorine (Clnat) analysis. The sample CoCal-N is derived from calcite crystals in a Namibian lag deposit, while the sample CoFsp-N is derived from a single crystal of alkali-felds...

Large continental earthquakes necessarily involve failure of multiple faults or segments. But these same critically-stressed systems sometimes fail in drawn-out sequences of smaller earthquakes over days or years instead. These two modes of failure have vastly different implications for seismic hazard and it is not known why fault systems sometimes...

The Altay Mountains of Western Mongolia accommodate 10-20% of the current shortening of the India-Asia collision in a transpressive regime. Kinematic models of the Altay require faults to rotate anticlockwise about a vertical axis in order to accommodate compressional deformation on the major strike slip faults that cross the region. Such rotations...

We provide a database of the coseismic geological surface effects following the Mw 6.5 Norcia earthquake that hit central Italy on 30 October 2016. This was one of the strongest seismic events to occur in Europe in the past thirty years, causing complex surface ruptures over an area of >400 km2. The database originated from the collaboration of sev...

We present a 1:25,000 scale map of the coseismic surface ruptures following the 30 October 2016 M w 6.5 Norcia normal-faulting earthquake, central Italy. Detailed rupture mapping is based on almost 11,000 oblique photographs taken from helicopter flights, that has been verified and integrated with field data (>7000 measurements). Thanks to the comm...

The temporal evolution of slip on surface ruptures during an earthquake is important for assessing fault displacement, defining seismic hazard and for predicting ground motion. However, measurements of near-field surface displacement at high temporal resolution are elusive. We present a novel record of near-field co-seismic displacement, measured w...

The number of studies using cosmogenic nuclides has increased multi-fold during the last two decades and several new dedicated target preparation laboratories and Accelerator Mass Spectrometry (AMS) facilities have been established. Each facility uses sample preparation and AMS measurement techniques particular to their needs. It is thus desirable...

Many areas of the Earth’s crust deform by distributed extensional faulting and complex fault interactions are often observed. Geodetic data generally indicate a simpler picture of continuum deformation over decades but relating this behaviour to earthquake occurrence over centuries, given numerous potentially active faults, remains a global problem...

Many areas of the Earth’s crust deform by distributed extensional faulting and the occurrence of earthquakes reflects complex fault interactions. Geodetic data may indicate a simpler picture of continuum deformation over decades but relating this behaviour to earthquake occurrence over centuries, given numerous potentially active faults, remains a...

We present some preliminary results on the mapping of coseismically-induced ground ruptures following the Aug. 24, 2016, Central Italy earthquake (Mw 6.0). The seismogenic source, as highlighted by InSAR and seismological data, ruptured across two adjacent structures: the Vettore and Laga faults. We collected field data on ground breaks along the w...

Surface slip distributions for an active normal fault in central Italy have been measured using terrestrial laser scanning (TLS), in order to assess the impact of changes in fault orientation and kinematics when modelling subsurface slip distributions that control seismic moment release. The southeastern segment of the surface trace of the Campo Fe...

Strain-rates have been measured in the central Italian Apennines in a regular 5km and 20km square grids using field measurements of fault geometry, slip vectors and throw-rates measured across offset Late Pleistocene-Holocene landforms and sediments. Comparisons of these strain-rates with rates derived from historical seismicity and geodesy show th...

Time-averaged fault slip-rates can be established by reliably dating the abandonment of an alluvial deposit that has been displaced by Quaternary movement along a cross-cutting fault. Unfortunately, many Quaternary dating techniques are hindered by uncertainties inherent to individual geochronometers. Such uncertainties can be minimised by combinin...

Time-averaged fault slip-rates can be established by reliably dating the abandonment of an alluvial deposit that has been displaced by Quaternary movement along a cross-cutting fault. Unfortunately, many Quaternary dating techniques are hindered by uncertainties inherent to individual geochronometers. Such uncertainties can be minimised by combinin...

The proximity of the Congo and Kalahari cratons during the Neoproterozoic breakup of the supercontinent Rodinia and during subsequent assembly of Gondwana is unclear. Neoproterozoic metasedimentary rocks from the rifted margins of Congo and Kalahari in the Damara Orogen yield distinctive detrital zircon U-Pb age distributions that correspond to the...

The Altay Mountains in western Mongolia are actively deforming as a far-field result of the collision between India and Asia. Convergence across the Altay is oblique, with at least six major fault zones present. Each of these fault zones preserves evidence for right-lateral strike-slip activity in the Quaternary, coupled with evidence for reverse-o...

The combination of the Sunda megathrust and the (strike-slip) Sumatran Fault (SF) represents a type example of slip-partitioning. However, superimposed on the SF are geometrical irregularities that disrupt the local strain field. The largest such feature is in central Sumatra where the SF splits into two fault strands up to 35 km apart. A dense loc...

The Mongolian Altai is an intracontinental oblique contractional orogen related to the far-field effects of the Indo-Asian collision. Global Positioning System (GPS) data suggest that ∼10–15 per cent of total Indo-Asia convergence is accommodated across this orogen. The Höh Serh–Tsagaan Salaa fault system is one of several NNW–SSE-trending oblique...

Active faults in the Altay Mountains, western Mongolia, produce surface expressions that are generally well-preserved due to the arid central-Asian climate. Motion along the right-lateral strike-slip and oblique-reverse faults has displaced major river systems by kilometres over millions of years and there are clear scarps and linear features in th...

The Precambrian history of the Earth is punctuated by a number of supercontinental assemblies and their disintegration. New paleomagnetic and geochronologic results from the Dharwar, Bundelkhand and Marwar cratons of the Indian subcontinent are presented here in an attempt to constrain the paleogeographic position of India within various proposed P...

New paleomagnetic and geochronologic data from the Malani Igneous Suite (MIS) in Rajasthan, northwest India, improve the paleogeographic reconstruction of the Indian subcontinent between dispersal of the Mesoproterozoic supercontinent Rodinia and late Neoproterozoic assembly of Gondwana. The MIS comprises voluminous phases of felsic and volumetrica...

Constraining the paleogeography of the Rodinia-Gondwana supercontinent cycle is an enigmatic problem that is largely complicated by the difficulties in discerning sutures that represent intercratonic basin closure versus ocean closure. The timing and tectonic style of the Gondwana supercontinent assembly can be tested by comparing detrital zircon g...

The Neoproterozoic to early Paleozoic Ural-Mongol belt that runs through Central Asia is crucial for determining the enigmatic amalgamation of microcontinents that make up the Eurasian subcontinent. Two unique models have been proposed for the evolution of Ural-Mongol belt. One involves a complex assemblage of cratonic blocks that have collided and...

Out of more than 2000 core samples that we collected during 2005-2006 field season, a paleomagnetic investigation was carried out from the doleritic to alkaline dikes intruding the Dharwar and Bastar cratons in Central and Southern India. Dike swarms were sampled for both paleomagnetic and geochronologic investigation with the goal of establishing...

The configuration of the Precambrian supercontinent Rodinia and the subsequent assembly of Gondwana are under considerable debate due to a paucity of high quality paleomagnetic data. The Indian continent is crucial to this topic and plays an essential role in the history of East Gondwana amalgamation. In proto-Gondwana reconstructions the location...

A paleomagnetic and geochronologic investigation was undertaken on the Majhgawan kimberlite near Panna, Central India. Mineral 40Ar/39Ar ages on phlogopite separates from the kimberlite yield a mean age of 1073.5 ± 13.7 Ma (2σ). Paleomagnetic samples from the brecciated kimberlite yielded a mean direction with a declination of 45.3° and an inclinat...

The late Neoproterozoic, c. 550 Ma, marks the estimated final assembly of the supercontinent Gondwana. Paleogeography of major cratons is relatively well established within Gondwana, but individual continental paleolocations prior to final Gondwana suturing are often poorly constrained. It is generally accepted that components of western Gondwana w...