@article{vadman_garvue_spotila_bemis_stamps_owen_figueiredo_2023, title={Evidence for a prehistoric multifault rupture along the southern Calico fault system, Eastern California Shear Zone, USA}, ISSN={["1553-040X"]}, DOI={10.1130/GES02653.1}, abstractNote={Geomorphic mapping and paleoseismologic data reveal evidence for a late Holocene multifault surface rupture along the Calico-Hidalgo fault system of the southern Eastern California Shear Zone (ECSZ). We have identified ~18 km of continuous surface rupture along the combined Calico and Hidalgo faults in the vicinity of Hidalgo Mountain in the southern Mojave Desert. Based on the freshness of geomorphic fault features and continuity of surface expression, we interpret this feature to reflect a simultaneous paleorupture of both faults. Displacement along the paleorupture is defined by 39 field measurements to be generally pure right-slip with a mean offset of 2.3 m. Scaling relationships for this offset amount imply that the original surface rupture length may have been ~82 km (corresponding to a M7.4 earthquake) and that much of the rupture trace was erased by subsequent erosion of sandy and unconsolidated valley alluvium. Eight luminescence ages from a paleoseismic trench across the paleorupture on the Hidalgo fault bracket the timing of the most recent rupture to 0.9–1.7 ka and a possible penultimate event at 5.5–6.6 ka. This timing is generally consistent with the known earthquake clusters in the southern ECSZ based on previous paleoseismic investigations. The ages of these earthquakes also overlap with the age brackets of the most recent events on the Calico fault 42 km to the north and the Mesquite Lake fault 40 km to the south from earlier work. Based on these age constraints and the expected surface rupture length, we propose that the Calico fault system experienced a major, multifault rupture that spanned the entire length of the fault system between the historical Landers and Hector Mine ruptures but preceded these events by ~1–2 k.y. Coulomb stress change modeling shows that the Calico paleorupture may have delayed the occurrence of the Landers-Hector Mine cluster by placing their respective faults in stress shadows and may have also prevented a triggered event from occurring on the Calico fault following the historic events. This work implies that closely spaced ruptures in complex shear zones may repel each other and thereby stretch out the duration of major earthquake clusters. These results also suggest that complex multifault ruptures in the ECSZ may not follow simple, repeatable patterns.}, journal={GEOSPHERE}, author={Vadman, Michael J. and Garvue, Max M. and Spotila, James A. and Bemis, Sean P. and Stamps, D. Sarah and Owen, Lewis A. and Figueiredo, Paula M.}, year={2023}, month={Sep} } @article{martinez_martinez_owen_2023, title={Human occupation, site formation, and chronostratigraphy of a mid-Holocene archaeological site at the eastern Pampa-Patagonia transition, Argentina}, ISSN={["1096-0287"]}, DOI={10.1017/qua.2023.8}, abstractNote={Abstract Intense aeolian processes in arid and semi-arid environments play an essential role in the preservation and destruction of archeological sites. This is especially the case in the lower basin of the Colorado River at the eastern Pampa-Patagonia Transition of Argentina, as is illustrated by geoarchaeological and chronostratigraphic studies at a mid-Holocene hunter-gatherer site, La Modesta, where aeolian processes strongly influence the archeological record in dune sediments. At La Modesta, surface archaeological materials are numerous and well preserved, although the stratigraphic record is incomplete. Optically stimulated luminescence (OSL) dating of sediments that contain cultural material provides a chronology dating from ca. 8.2 ka but shows one or more hiatuses from ca. 6–2 ka in the sedimentary succession. Intense morphogenesis related to arid climates likely caused gaps in sedimentation, affecting the integrity and resolution of the archaeological record. This study helps explain mid-Holocene archaeological discontinuities throughout central Argentina and highlights the importance of considering taphonomic and geologic biases when dealing with the absence or reduction of the archaeological record in dryland regions.}, journal={QUATERNARY RESEARCH}, author={Martinez, Gustavo and Martinez, Gustavo Adolfo and Owen, Lewis A.}, year={2023}, month={Apr} } @article{chansom_jitmahantakul_owen_wiwegwin_charusiri_2023, title={New insights into the paleoseismic history of the Mae Hong Son Fault, Northern Thailand (vol 10, 921049, 2022)}, volume={11}, ISSN={["2296-6463"]}, DOI={10.3389/feart.2023.1231866}, abstractNote={CORRECTION article Front. Earth Sci., 08 June 2023Sec. Structural Geology and Tectonics Volume 11 - 2023 | https://doi.org/10.3389/feart.2023.1231866}, journal={FRONTIERS IN EARTH SCIENCE}, author={Chansom, Chanista and Jitmahantakul, Sukonmeth and Owen, Lewis A. A. and Wiwegwin, Weerachat and Charusiri, Punya}, year={2023}, month={Jun} } @article{yan_owen_guo_zhang_zhang_wang_2023, title={Widespread glacier advances across the Tian Shan during Marine Isotope Stage 3 not supported by climate-glaciation simulations}, volume={3}, ISSN={["2667-3258"]}, DOI={10.1016/j.fmre.2022.01.033}, abstractNote={Whether there were more extensive glaciations during the Marine Isotope Stage (MIS) 3 relative to MIS 2 across the Tian Shan in Central Asia is intensely debated because of the uncertainty in chronological data and fully understanding the driving mechanisms. To help resolve the ongoing debate, we assess the climate sensitivity of the glaciers and reconstruct the extent of glaciation during MIS 2 and 3 across the Tian Shan, using a glacier-resolving (250 × 250 m) ice sheet model asynchronously coupled with a global climate model. Our results demonstrate that the equilibrium-line altitude (ELA) over the Tian Shan decreases by ∼180 m for every 1 °C cooling under a modern precipitation regime, but precipitation reduction greatly lowers the sensitivity of the glaciers to temperature decrease (e.g., the effect of 2 °C cooling is broadly offset by a 50% decrease in precipitation). Under the modeled colder/drier-than-present climate, the model predicts an ELA depression (∆ELA) of ∼75 m (162 m) over the Tian Shan during MIS 3 interstadials (stadials). The extent of MIS 3 glaciation is much smaller than that during MIS 2 (i.e., ∆ELA = ∼726 m). The more extensive glaciation during MIS 2 is largely attributed to the enhanced summer cooling. Furthermore, through a site-to-site model-data comparison, we find that the closest match between the modeled glacier margin and the locations of the glacial deposits previously argued to be MIS 3 is generally achieved under MIS 2 climatic conditions. These results suggest more extensive glacier advances over the Tian Shan during MIS 2 than MIS 3 on a regional scale, although MIS 3 glaciation may still occur in individual glacier catchments. This pattern suggests general synchronicity with the timing of maximum Northern Hemisphere ice sheets during the last glacial, which should be further tested in a multimodel framework in the future.}, number={1}, journal={FUNDAMENTAL RESEARCH}, author={Yan, Qing and Owen, Lewis A. and Guo, Chuncheng and Zhang, Zhongshi and Zhang, Jinzhe and Wang, Huijun}, year={2023}, month={Jan}, pages={102–110} } @article{luo_chen_owen_qin_yin_yang_liu_gong_luo_2022, title={A Novel Approach for Reconstructing Slip Histories for Bedrock Fault Scarps Using Rock Surface Luminescence Dating}, volume={49}, ISSN={["1944-8007"]}, DOI={10.1029/2022GL099526}, abstractNote={Abstract A newly developing method, optically stimulated luminescence (OSL)‐depth profiles (DPs), provides a novel means of reconstructing and quantifying fault slip on timescales of 10 1−4 years. A targeted bedrock fault scarp along Langshan in north China, used as proof of concept, is divided into four sections based on four groups of OSL‐DPs at different heights up the bedrock fault scarp. These have seismic displacements of 170, 80, 130, and 140 cm, and without considering the erosion rate, the exposure ages at the four displacements are 6–35 a, 19–84 a, 0.5–0.9 ka, and 2–5 ka, respectively. The ages are overall in chronological order, while the actual ages are likely underestimated due to erosion. After assuming erosion amounts according to the weathering characteristics, the calculated ages are mostly consistent with paleoseismic trenching studies. In addition, the method may identify a seismic event that previous studies did not identify.}, number={16}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Luo, Ming and Chen, Jie and Owen, Lewis A. and Qin, Jintang and Yin, Jinhui and Yang, Huili and Liu, Jinfeng and Gong, Zhijun and Luo, Jiahong}, year={2022}, month={Aug} } @article{hamahashi_hubbard_almeida_haines_owen_mishra_sapkota_2022, title={Fluvial Sedimentary Response to Late Quaternary Climate and Tectonics at the Himalayan Frontal Thrust, Central Nepal}, volume={23}, ISSN={["1525-2027"]}, DOI={10.1029/2022GC010366}, abstractNote={Abstract To investigate the subsurface structure surrounding the Main Frontal Thrust (MFT) in central Nepal, we drilled and cored sediments to depths of 45–100 m at 10 sites. Our boreholes were located along previously acquired high‐resolution seismic profiles across the MFT imaging the upper 1–2 km of the subsurface, which revealed a beveled erosional surface in the hanging wall above a broad, gentle anticline, as well as growth strata in the footwall. The boreholes exhibit interlayered clays, silts, sands, and gravels, dated with optically stimulated luminescence and radiocarbon to <72.5 ± 4.3 ka, with a transition from finer to coarser sediments at ∼13.5 ± 0.1 ka. Near the fault tip, the deposits exhibit steeper dips and deformation bands. A 25‐m‐thick section of silt and clay above the south end of the buried anticline is interpreted as a temporary lacustrine depocenter formed due to uplift near the fault tip. Based on the distribution of marker beds and sediment ages, we interpret a shortening rate of 3.1–12.1 m/ka on the MFT. Three major transitions between fluvial‐lacustrine and coarse fluvial channel facies are inferred from the boreholes, and the timings of these transitions correlate with Indian monsoonal intensity variations linked to Earth's precession. We infer that a strengthened monsoon led to increased river discharge and advance of coarse bedload‐dominant braided channels, whereas a weak monsoon formed a finer‐grained channel environment. These monsoonal climate variations have affected the depositional environment and river base levels in this region, influencing the formation and apparent relative uplift of nearby river terraces.}, number={9}, journal={GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS}, author={Hamahashi, Mari and Hubbard, Judith A. and Almeida, Rafael V and Haines, Samuel H. and Owen, Lewis A. and Mishra, Sanjita and Sapkota, Soma Nath}, year={2022}, month={Sep} } @article{chansom_jitmahantakul_owen_wiwegwin_charusiri_2022, title={New Insights Into the Paleoseismic History of the Mae Hong Son Fault, Northern Thailand}, volume={10}, ISSN={["2296-6463"]}, DOI={10.3389/feart.2022.921049}, abstractNote={The Mae Hong Son Fault (MHSF) is a north-trending active fault in northern Thailand. The largest earthquake ever recorded in Thailand occurred in February 1975 with a magnitude of 5.6 and was associated with the southern end of the MHSF. Paleoearthquake magnitudes, recurrence intervals, and slip rates for the MHSF are evaluated using the morphological characteristics of the MHSF aided with a 12.5-m-resolution digital elevation model (DEM) and using fault trenching. Morphotectonic analysis, including studies of offset streams, linear valleys, triangular facets, and fault scarps, helps illustrate dextral fault movements within the MHSF zone. Two separated N–S trending basins, the Mae Hong Son to the north and the Mae Sariang to the south, are present along the MHSF. Between these basins, fault displacements decrease toward the Khun Yuam area. Surface rupture length investigation from fault segments in both basins indicates maximum credible earthquake magnitudes between 5.8 and 6.3. Fault trenching and road-cut studies show that nine earthquakes occurred along the MHSF over the past ∼43 ka. Optically stimulated luminescence (OSL) dating help define the timing of the earthquakes to ∼43, ∼38, ∼33, ∼28, ∼23, ∼18, ∼13, ∼8, and ∼3 ka. The recurrence interval of earthquakes on the Mae Hong Son Fault is ∼5,000 years and the fault has a slip rate of ∼0.04–0.15 mm/a.}, journal={FRONTIERS IN EARTH SCIENCE}, author={Chansom, Chanista and Jitmahantakul, Sukonmeth and Owen, Lewis A. and Wiwegwin, Weerachat and Charusiri, Punya}, year={2022}, month={Jul} } @article{rockwell_costa_meigs_ragona_owen_murari_masana_richard_2022, title={Pateoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina}, volume={10}, ISSN={["2296-6463"]}, DOI={10.3389/feart.2022.1032357}, abstractNote={Excavated trenches at two sites across the Marquesado–La Rinconada fault system along the eastern Precordilleran front south of San Juan, Argentina, reveal the earthquake history of this rapidly urbanizing region. Interpretation of earthquakes is based on both the generation of colluvial wedges and upward fault terminations, as well as folding events in fine-grained alluvium ponded behind upslope-facing fault scarps. The ages of the past five interpreted earthquakes at the Loma Negra site are E1 at 2.8 ± 2.8 ka, E2 at 7.1 ± 1.5 ka, E3 at 9.6 ± 1.3 ka, E4 at 14.4 ± 2.1 ka, and E5 at 17.2 ± 3.1 ka. At the Jejenes sites, we documented event ages of 2.7 ± 0.1 ka, 3.9 ± 0.6 ka, 5.9 ± 1.3 ka, and 11.4 ± 4 ka. These results indicate that the recurrence interval along the Marquesado–La Rinconada fault zone averages several thousand years. The inferred displacements at the Jejenes site are about 1.1 m for E1, E3, and E4 and 2.1 m for event E2, whereas the displacements at Loma Negra averaged about 1 m, but the most recent event displays less slip. Notably, the older events seem to have been larger and emergent, whereas the youngest event appears to have been smaller and blind in the ponded sediment; this may partially explain the poor expression of classic colluvial wedges associated with some events. Despite the fact that active surface faulting has an uncertain relationship with the primary seismic sources at depth in the crust, past and future events of M w ∼7.5 are consistent with the length scale of active deformation, the ∼1–2 m slip per event scale of these ruptures, and the size of historical earthquakes.}, journal={FRONTIERS IN EARTH SCIENCE}, author={Rockwell, Thomas K. K. and Costa, Carlos H. H. and Meigs, Andrew J. J. and Ragona, Daniel and Owen, Lewis A. A. and Murari, Madhav Krishna and Masana, Eulalia and Richard, Andres D.}, year={2022}, month={Dec} } @article{ozpolat_yildirim_gorum_gosse_sahiner_sarikaya_owen_2022, title={Three-dimensional control of alluvial fans by rock uplift in an extensional regime: Aydin Range, Aegean extensional province}, volume={12}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-022-19795-0}, abstractNote={Abstract Tectonics imparts a first-order control on the overall morphology of alluvial fan systems in extensional settings by influencing sediment flux and accommodation space, while other factors such as climate, catchment lithology, and fault footwall characteristics are secondary. Previous alluvial fan modeling studies have focused on the link between the three-dimensional development of alluvial fans and rock uplift, however, despite the potential influence of tectonics on the overall three-dimensional morphology of alluvial fans, the controlling mechanisms, as well as their relative importance, remain largely unquantified in a natural setting with a targeted source-to-sink approach. Here, we examine 45 alluvial fans and their catchments along the southern mountain front of the Aydın Range, delimited by segmented normal faults in the western Anatolia Extensional Province, to quantify the role of rock uplift. We quantify river incision rates and catchment-wide erosion rates together with a series of topographic analyses across the southern flank of the Aydın Range as a proxy for rock uplift. Our results indicate that the spatial distribution of thicker and steeper alluvial fans fit well with higher rock uplift rates along the strike of the mountain front. In contrast, a lower uplift rate is responsible for prograding alluvial fans with decreasing thickness and gradients. Also, our data shows that alluvial fan thickness compared to other alluvial fan metrics strongly associated with the pattern of the rock uplift. This study demonstrates a field-based, quantitative linkage between three-dimensional alluvial fan morphology and rock uplift which has significant implications for improving alluvial fan models and understanding how alluvial fans respond to tectonics in extensional regions.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Ozpolat, Emrah and Yildirim, Cengiz and Gorum, Tolga and Gosse, John C. and Sahiner, Eren and Sarikaya, M. Akif and Owen, Lewis A.}, year={2022}, month={Sep} } @article{teller_owen_2021, title={Age of Gimli beach of Lake Agassiz based on new OSL dating}, volume={36}, ISSN={["1099-1417"]}, DOI={10.1002/jqs.3257}, abstractNote={ABSTRACT Gimli beach in Manitoba is one of the lowest elevation beaches in the southern Lake Agassiz basin, and is a distinct ridge composed of bedded sand and gravel that rises above the lake plain and extends for more than 40 km. Ten new optically stimulated luminescence (OSL) ages from Gimli beach yield ages mostly ranging from 9.7 ± 0.7 to 10.5 ± 0.8 ka (average 10.3 ± 0.5 ka), which is older by 0.6 to >1.0 ka than age estimates of previous researchers. Two of our new OSL ages are notably older than the others, dating to ~11.3 ± 0.8 and 13.9 ± 1.0 ka, which we attribute to poorly bleached sands. We ascribe an age of about 10 ka to Gimli beach, which is several centuries before overflow from Lake Agassiz and its vast drainage basin shifted from the western Great Lakes to glacial Lake Ojibway and the St. Lawrence Valley.}, number={1}, journal={JOURNAL OF QUATERNARY SCIENCE}, author={Teller, James T. and Owen, Lewis A.}, year={2021}, month={Jan}, pages={56–65} } @article{harmon_khashchevskaya_morency_owen_jennings_knott_dortch_2021, title={Analysis of Rock Varnish from the Mojave Desert by Handheld Laser-Induced Breakdown Spectroscopy}, volume={26}, ISSN={["1420-3049"]}, DOI={10.3390/molecules26175200}, abstractNote={Laser-induced breakdown spectroscopy (LIBS) is a form of optical emission spectroscopy that can be used for the rapid analysis of geological materials in the field under ambient environmental conditions. We describe here the innovative use of handheld LIBS for the in situ analysis of rock varnish. This thinly laminated and compositionally complex veneer forms slowly over time on rock surfaces in dryland regions and is particularly abundant across the Mojave Desert climatic region of east-central California (USA). Following the depth profiling examination of a varnished clast from colluvial gravel in Death Valley in the laboratory, our in situ analysis of rock varnish and visually similar coatings on rock surfaces was undertaken in the Owens and Deep Spring valleys in two contexts, element detection/identification and microchemical mapping. Emission peaks were recognized in the LIBS spectra for the nine elements most abundant in rock varnish—Mn, Fe, Si, Al, Na, Mg, K, Ca and Ba, as well as for H, Li, C, O, Ti, V, Sr and Rb. Focused follow-up laboratory and field studies will help understand rock varnish formation and its utility for weathering and chronological studies.}, number={17}, journal={MOLECULES}, author={Harmon, Russell S. and Khashchevskaya, Daria and Morency, Michelle and Owen, Lewis A. and Jennings, Morgan and Knott, Jeffrey R. and Dortch, Jason M.}, year={2021}, month={Sep} } @article{orr_owen_saha_caffee_2021, title={Climate-driven late Quaternary fan surface abandonment in the NW Himalaya}, volume={548}, ISBN={["978-0-8137-2548-2"]}, ISSN={["0072-1077"]}, DOI={10.1130/2020.2548(04)}, abstractNote={ABSTRACT We defined the timing of surface abandonment for 10 alluvial and debris-flow fans across contrasting climatic settings in the NW Himalaya of northern India using cosmogenic 10Be surface exposure dating. Debris-flow fans in the Garhwal, Kullu, and Lahul-Spiti regions of the monsoon-influenced Greater Himalaya were largely abandoned during the Mid- to Late Holocene. Large alluvial fans and smaller debris-flow fans in the semiarid Ladakh region of the Greater and Tethyan Himalaya have surface ages that extend throughout the last glacial. Regional events of landform abandonment and incision were defined for the monsoon-influenced western Himalaya ranges and the semiarid western Himalaya ranges over the past ~120 k.y. In the monsoon-influenced and semiarid western Himalaya ranges, these regional events were limited to the Holocene and from ca. 40 ka, respectively. The timing of fan surface abandonment and regional landform abandonment events coincided with periods of weakening monsoon strength and cooling, and local and regional glacier advances. Regional incision events from the monsoon-influenced and semiarid western Himalaya regions were recognized across various climatic conditions due to the ubiquitous nature of erosion in mountain settings. This study showed that climate-driven processes and glaciation were important drivers in fan sedimentation, catchment sediment flux, and the topographic evolution of the NW Himalaya during the late Quaternary.}, journal={UNTANGLING THE QUATERNARY PERIOD}, author={Orr, Elizabeth N. and Owen, Lewis A. and Saha, Sourav and Caffee, Marc W.}, year={2021}, pages={63–80} } @article{yan_owen_zhang_wang_wei_jiang_zhang_2021, title={Divergent Evolution of Glaciation Across High-Mountain Asia During the Last Four Glacial-Interglacial Cycles}, volume={48}, ISSN={["1944-8007"]}, DOI={10.1029/2021GL092411}, abstractNote={Glaciers over High-Mountain Asia (HMA) provide a critical window into past climate change and the linkage between high and low-latitude glaciation, but how glaciers may have varied during past glacial-interglacial cycles remains elusive. Here, we reconstruct the timing and extent of glaciations for the last 425 kyr over HMA, using a climate-glaciation simulation constrained by observations and glacial geologic evidence. We illustrate that there were multiple alpine-style glaciations comparable in extent to those during the last glacial maximum during the last four glacial-interglacial cycles. The extent and timing of glaciations vary across HMA, especially between the westerly influenced northern and the monsoonal-influenced southern HMA. The ∼23-kyr periodicity dominates HMA glaciation due to the critical role of precession in regulating summer temperature and precipitation. Our results, in addition to helping to fill the incomplete glacial geologic record, provide a framework to test hypotheses linking orbital-scale climate, glaciation, and landscape evolution over HMA.}, number={11}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Yan, Qing and Owen, Lewis A. and Zhang, Zhongshi and Wang, Huijun and Wei, Ting and Jiang, Nanxuan and Zhang, Ran}, year={2021}, month={Jun} } @article{lentz_slotten_dunning_jones_scarborough_mccool_owen_fladd_tankersley_perfetta_et al._2021, title={Ecosystem impacts by the Ancestral Puebloans of Chaco Canyon, New Mexico, USA}, volume={16}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0258369}, abstractNote={The Ancestral Puebloans occupied Chaco Canyon, in what is now the southwestern USA, for more than a millennium and harvested useful timber and fuel from the trees of distant forests as well as local woodlands, especially juniper and pinyon pine. These pinyon juniper woodland products were an essential part of the resource base from Late Archaic times (3000-100 BC) to the Bonito phase (AD 800-1140) during the great florescence of Chacoan culture. During this vast expanse of time, the availability of portions of the woodland declined. We posit, based on pollen and macrobotanical remains, that the Chaco Canyon woodlands were substantially impacted during Late Archaic to Basketmaker II times (100 BC-AD 500) when agriculture became a major means of food production and the manufacture of pottery was introduced into the canyon. By the time of the Bonito phase, the local woodlands, especially the juniper component, had been decimated by centuries of continuous extraction of a slow-growing resource. The destabilizing impact resulting from recurrent woodland harvesting likely contributed to the environmental unpredictability and difficulty in procuring essential resources suffered by the Ancestral Puebloans prior to their ultimate departure from Chaco Canyon.}, number={10}, journal={PLOS ONE}, author={Lentz, David L. and Slotten, Venicia and Dunning, Nicholas P. and Jones, John G. and Scarborough, Vernon L. and Mccool, Jon-Paul and Owen, Lewis A. and Fladd, Samantha G. and Tankersley, Kenneth B. and Perfetta, Cory J. and et al.}, year={2021}, month={Oct} } @article{young_gordon_owen_huot_zerfas_2021, title={Evidence for a late glacial advance near the beginning of the Younger Dryas in western New York State: An event postdating the record for local Laurentide ice sheet recession}, volume={17}, ISSN={["1553-040X"]}, DOI={10.1130/GES02257.1}, abstractNote={Abstract Widespread evidence of an unrecognized late glacial advance across preexisting moraines in western New York is confirmed by 40 14C ages and six new optically stimulated luminescence analyses between the Genesee Valley and the Cattaraugus Creek basin of eastern Lake Erie. The Late Wisconsin chronology is relatively unconstrained by local dating of moraines between Pennsylvania and Lake Ontario. Few published 14C ages record discrete events, unlike evidence in the upper Great Lakes and New England. The new 14C ages from wood in glacial tills along Buttermilk Creek south of Springville, New York, and reevaluation of numerous 14C ages from miscellaneous investigations in the Genesee Valley document a significant glacial advance into Cattaraugus and Livingston Counties between 13,000 and 13,300 cal yr B.P., near the Greenland Interstadial 1b (GI-1b) cooling leading into the transition from the Bölling-Alleröd to the Younger Dryas. The chronology from four widely distributed sites indicates that a Late Wisconsin advance spread till discontinuously over the surface, without significantly modifying the preexisting glacial topography. A short-lived advance by a partially grounded ice shelf best explains the evidence. The advance, ending 43 km south of Rochester and a similar distance south of Buffalo, overlaps the revised chronology for glacial Lake Iroquois, now considered to extend from ca. 14,800–13,000 cal yr B.P. The spread of the radiocarbon ages is similar to the well-known Two Creeks Forest Bed, which equates the event with the Two Rivers advance in Wisconsin.}, number={1}, journal={GEOSPHERE}, author={Young, Richard A. and Gordon, Lee M. and Owen, Lewis A. and Huot, Sebastien and Zerfas, Timothy D.}, year={2021}, month={Feb}, pages={271–305} } @article{arkle_weber_enkelmann_owen_govers_jess_denison_paul b. o'sullivan_donelick_2021, title={Exhumation of the Costal Metamorphic Belt Above the Subduction-to-Transform Transition, in the Southeast Caribbean Plate Corner}, volume={40}, ISSN={["1944-9194"]}, DOI={10.1029/2020TC006414}, abstractNote={Plate corners that transition from subduction to transform motion can result in complex deformation. The southeastern corner of the Caribbean plate is a site where active westward subduction of the oceanic South American plate transitions to transform motion along continental South America. The Northern Range (Trinidad) and Paria (Venezuela) metamorphic mountains are located directly above this eastward propagating plate transition zone. We examined the exhumation history of the Northern Range and eastern Paria using apatite fission track (AFT) and apatite and zircon (U-Th)/He (AHe and ZHe, respectively) thermochronology on 21 bedrock samples. These samples yield ages of ∼43–6 Ma (ZHe: aliquots), ∼20–4 Ma (AFT: pooled) and ∼5–2 Ma (AHe: aliquots). Along strike of the mountains, our new and published samples show a gradual eastward increase in age. Thermal modeling reveals two phases of rapid cooling and inferred exhumation that post-dates oblique collision and that migrated from west to east. We record an ∼six-fold increase in cooling and exhumation between ∼13–9 Ma in the Paria Peninsula and western Northern Range; a deceleration followed this rapid exhumation at ∼7 and 5 Ma. Synchronous with the deceleration in the west, exhumation of the eastern Northern Range increased ∼4 Ma. These post-collisional changes in exhumation constrain the inversion to east-side-up tilting of the Northern Range to ∼4 Ma. We interpret the timing and pattern of exhumation since the mid-Miocene to be consistent with the time-transgressive processes produced by an eastward propagating lithospheric subduction-transform edge propagator fault.}, number={8}, journal={TECTONICS}, author={Arkle, Jeanette C. and Weber, John and Enkelmann, Eva and Owen, Lewis A. and Govers, Rob and Jess, Scott and Denison, Chris and Paul B. O'Sullivan and Donelick, Raymond A.}, year={2021}, month={Aug} } @article{hong_lee_seong_owen_rhee_lee_yoo_2021, title={Holocene sea-level history and tectonic implications derived from luminescence dating of raised beaches in Terra Nova Bay, Antarctica}, volume={25}, ISSN={["1598-7477"]}, DOI={10.1007/s12303-020-0031-x}, number={3}, journal={GEOSCIENCES JOURNAL}, author={Hong, Seongchan and Lee, Min Kyung and Seong, Yeong Bae and Owen, Lewis A. and Rhee, Hyun Hee and Lee, Jae Il and Yoo, Kyu-Cheul}, year={2021}, month={Jun}, pages={283–298} } @article{karlsson_rockwell_fletcher_figueiredo_cambron rosas_gontz_naik_lacan_spelz_owen_et al._2021, title={Large Holocene ruptures on the Canada David detachment, Baja California, Mexico; implications for the seismogenesis of low-angle normal faults}, volume={570}, ISSN={["1385-013X"]}, url={https://doi.org/10.1016/j.epsl.2021.117070}, DOI={10.1016/j.epsl.2021.117070}, abstractNote={We present the results of detailed mapping and paleoseismic investigations along a section of the complex fault scarp array associated with the Cañada David detachment, a low-angle oblique normal fault that controls the southwestern flank of the Sierra El Mayor, Baja California, Mexico. We used high-resolution unmanned aerial vehicle imagery to map portions of a sequence of alluvial fans that comprise a bajada that flanks the southwestern range front. Their ages are distinguished based on a regional soil chronosequence. Three paleoseismic trenches were excavated across active surface faults that root into the Cañada David detachment at depth. Fine-grained stratigraphic units in the trenches were dated by optically stimulated luminescence techniques. The three trenches in this study show strong evidence for four large (Mw≥7) Holocene earthquakes at or just prior to about 1.7, 4.3–6.1, 7.7–7.6 and 8.4–10.7 ka, as well as weak to moderate evidence for two additional late Pleistocene earthquakes at or just prior to 12.7–14.1 ka and 15.2 ka, indicating an average recurrence of such events of ∼3 ka. This earthquake recurrence interval is slightly longer than that for the Laguna Salada fault to the north that flanks the Sierra Cucapah. The regular recurrence of major surface ruptures strongly suggests that severely-misoriented low-angle normal faults like the Cañada David detachment have a mechanical behavior that is very similar to other more optimally oriented faults suggesting that earthquakes on such faults should be common and may be difficult to recognize from seismologic methods due rolling-hinge ramps and/or multifault ruptures.}, journal={EARTH AND PLANETARY SCIENCE LETTERS}, publisher={Elsevier BV}, author={Karlsson, Keene W. and Rockwell, Thomas K. and Fletcher, John M. and Figueiredo, Paula M. and Cambron Rosas, Jaziel Froylan and Gontz, Allen M. and Naik, Sambit Prasanajit and Lacan, Pierre and Spelz, Ronald M. and Owen, Lewis A. and et al.}, year={2021}, month={Sep} } @article{counts_van arsdale_woolery_murari_owen_beck_mahan_durbin_2021, title={Late Holocene Deformation near the Southern Limits of the Wabash Valley Seismic Zone of Kentucky and Indiana, Central United States, with Seismic Implications}, volume={111}, ISSN={["1943-3573"]}, DOI={10.1785/0120190089}, abstractNote={ABSTRACT The Wabash Valley seismic zone (WVSZ) is a region of diffuse, modern intraplate seismicity in the central United States with a history of strong, late Quaternary and Holocene seismicity as determined through paleoliquefaction studies. Yet, there are no specific faults linked to these strong WVSZ paleoearthquakes, some of which were as large as Mw 7.2–7.5. A multidisciplinary investigation of a linear, 5-kilometer-long and ∼3-meter-high scarp on the Ohio River floodplain in the southernmost WVSZ in western Kentucky evaluated whether the scarp is a fluvial landform or a tectonic feature. Geomorphic mapping and optically stimulated luminescence geochronology show that the age and orientation of the scarp are inconsistent with surrounding fluvial landforms. Trenching, core drilling, seismic reflection, electrical resistivity profiling, and cross sections of petroleum well logs all indicate a blind fault directly underlies the scarp. The scarp is interpreted to be the fold axis of a down-to-the-west monocline formed in alluvium by slip on the underlying blind fault, herein named the Uniontown fault. The Uniontown fault connects the Hovey Lake fault, striking N20°E and having ∼0.5 km of documented strike-slip offset, with an unnamed fault complex to the south that strikes N40°E, suggesting the Uniontown fault is part of a larger, Paleozoic structure that has been reactivated with strike-slip deformation. Geomorphic mapping utilizing luminescence and radiocarbon geochronology indicates that folding and faulting occurred ∼3.5 ka. Paleoliquefaction was suppressed by a thick clay cap in the main Ohio Valley, but paleoliquefaction features are widespread on Ohio River tributaries. Gravel dikes at one site had a maximum age of 3.4±0.4 ka, confirming the region has experienced strong, late Holocene shaking. Estimates using vertical displacement and rupture length indicate that slip on the Uniontown scarp could produce an Mw 6.2–7.7 earthquake, which is comparable to other large paleoearthquakes in the WVSZ paleoseismic record.}, number={2}, journal={BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA}, author={Counts, Ronald C. and Van Arsdale, Roy and Woolery, Edward and Murari, Madhav K. and Owen, Lewis A. and Beck, E. Glynn and Mahan, Shannon and Durbin, James}, year={2021}, month={Apr}, pages={1154–1179} } @article{rimando_schoenbohm_ortiz_alvarado_venerdini_owen_seagren_figueiredo_hammer_2021, title={Late Quaternary Intraplate Deformation Defined by the Las Chacras Fault Zone, West-Central Argentina}, volume={40}, ISSN={["1944-9194"]}, url={https://doi.org/10.1029/2020TC006509}, DOI={10.1029/2020TC006509}, abstractNote={Abstract Several major (up to M W 7.5) earthquakes over the past 320 years have shaken the thick‐skinned Sierras Pampeanas region of Argentina, despite exhibiting much lower GPS‐shortening rates than across the thin‐skinned Precordillera region to its west. Whether geodetic shortening rates indicate an actual long‐term shortening gradient, and whether shortening rates translate to higher uplift rates due to steeper faults in the Sierras Pampeanas, remain uncertain due to the limited spatio‐temporal coverage and the inherently large error in the vertical component of deformation of GPS measurements. We measure geomorphic offsets and use 10 Be terrestrial cosmogenic nuclide surface exposure dating to determine slip rates on the Las Chacras Fault Zone (LCFZ)—an ∼30 km long, NNW‐trending, steeply dipping (55–65°E) reverse fault that branches off of the longest, westernmost, thick‐skinned Valle Fértil range‐front fault in the western Sierras Pampeanas. Average shortening and uplift rates measured on the LCFZ are ∼0.2 and ∼0.3–0.4 mm/yr, respectively. Despite an uplift rate similar to most other faults in the region, the LCFZ shortening rate is lower than faults to its west; this is in agreement with the inferred west‐east decrease in shortening rates from GPS data, indicating consistent regional deformation patterns since the Late Pleistocene. The decrease in shortening to the east coincides spatially with the termination of the flat portion of the subducted Nazca plate between 67 and 68°W. From scaling relationships among magnitude, slip rate, and fault length, the LCFZ is capable of generating earthquakes of M W 6.7–7.1.}, number={4}, journal={TECTONICS}, publisher={American Geophysical Union (AGU)}, author={Rimando, Jeremy M. and Schoenbohm, Lindsay M. and Ortiz, Gustavo and Alvarado, Patricia and Venerdini, Agostina and Owen, Lewis A. and Seagren, Erin G. and Figueiredo, Paula Marques and Hammer, Sarah}, year={2021}, month={Apr} } @article{ozpolat_sahiner_ozcan_demir_owen_2021, title={Late-Holocene landscape evolution of a delta from the foredune ridges: Seyhan Delta, the Eastern Mediterranean, Turkey}, volume={31}, ISSN={["1477-0911"]}, DOI={10.1177/0959683620988047}, abstractNote={The Çukurova Delta Complex, formed by the Seyhan, Ceyhan, and Berdan rivers, is the second-largest delta system in the Mediterranean. The delta complex is a major depocenter that contains sediments transported from the Taurus Mountain belt since the Miocene. Studies on the Quaternary landscape evolution of the Çukurova Delta Complex are scarce, and in particular, the Holocene evolution of the Seyhan Delta section of the Çukurova Delta Complex has been poorly understood. Sedimentological analysis, high-resolution digital elevation models derived using structure from motion, and optically stimulated luminescence dating of the foredune ridges in the Seyhan Delta help define the lesser-known nature of Late-Holocene paleoenvironmental and landscape evolution of the Seyhan section of the Çukurova Delta Complex. The foredune ridges provide evidence that the Akyatan Lagoon, one of Turkey’s largest lagoon, formed at the beginning of the last millennium. The ridges bordering the north and south of Tuzla Lagoon show that the lagoon completed its formation between the 11th and 14th centuries when the ancient delta was to the east. The Seyhan River flowed 10 km east from its current course until at least the 16th Century, and its ancient delta was active until that time. After the 16th Century, the Seyhan River shifted to its current course in the west and began to build the modern delta and the youngest foredune ridges were formed by a combination of aeolian and littoral processes. The contemporary delta continued to prograde until the construction of the Seyhan Dam in AD 1956. Since the construction of the Seyhan Dam, the delta shoreline at the river mouth retreated drastically and foredune formation stopped. In the past few decades, most of the foredune ridges have been eroded away by coastal processes and agricultural activities.}, number={5}, journal={HOLOCENE}, author={Ozpolat, Emrah and Sahiner, Eren and Ozcan, Orkan and Demir, Tuncer and Owen, Lewis A.}, year={2021}, month={May}, pages={760–777} } @article{mcgill_owen_weldon_kendrick_burgette_2021, title={Latest Quaternary slip rates of the San Bernardino strand of the San Andreas fault, southern California, from Cajon Creek to Badger Canyon}, volume={17}, ISSN={["1553-040X"]}, DOI={10.1130/GES02231.1}, abstractNote={Abstract Four new latest Pleistocene slip rates from two sites along the northwestern half of the San Bernardino strand of the San Andreas fault suggest the slip rate decreases southeastward as slip transfers from the Mojave section of the San Andreas fault onto the northern San Jacinto fault zone. At Badger Canyon, offsets coupled with radiocarbon and optically stimulated luminescence (OSL) ages provide three independent slip rates (with 95% confidence intervals): (1) the apex of the oldest dated alluvial fan (ca. 30–28 ka) is right-laterally offset ~300–400 m yielding a slip rate of 13.5 +2.2/−2.5 mm/yr; (2) a terrace riser incised into the northwestern side of this alluvial fan is offset ~280–290 m and was abandoned ca. 23 ka, yielding a slip rate of 11.9 +0.9/−1.2 mm/yr; and (3) a younger alluvial fan (13–15 ka) has been offset 120–200 m from the same source canyon, yielding a slip rate of 11.8 +4.2/−3.5 mm/yr. These rates are all consistent and result in a preferred, time-averaged rate for the past ~28 k.y. of 12.8 +5.3/−4.7 mm/yr (95% confidence interval), with an 84% confidence interval of 10–16 mm/yr. At Matthews Ranch, in Pitman Canyon, ~13 km northwest of Badger Canyon, a landslide offset ~650 m with a 10Be age of ca. 47 ka yields a slip rate of 14.5 +9.9/−6.2 mm/yr (95% confidence interval). All of these slip rates for the San Bernardino strand are significantly slower than a previously published rate of 24.5 ± 3.5 mm/yr at the southern end of the Mojave section of the San Andreas fault (Weldon and Sieh, 1985), suggesting that ~12 mm/yr of slip transfers from the Mojave section of the San Andreas fault to the northern San Jacinto fault zone (and other faults) between Lone Pine Canyon and Badger Canyon, with most (if not all) of this slip transfer happening near Cajon Creek. This has been a consistent behavior of the fault for at least the past ~47 k.y.}, number={5}, journal={GEOSPHERE}, author={McGill, Sally F. and Owen, Lewis A. and Weldon, Ray J. and Kendrick, Katherine J. and Burgette, Reed J.}, year={2021}, month={Oct}, pages={1354–1381} } @article{costa_owen_johnson_kirby_2021, title={Quaternary activity and seismogenic potential of the Sierra Chica Fault System, Pampean Ranges of Argentina}, volume={110}, ISSN={["1873-0647"]}, DOI={10.1016/j.jsames.2021.103328}, abstractNote={The Sierra Chica Fault System (SCFS) is a west-vergent thrust bounding the easternmost basement uplift in the Pampean Ranges of Argentina. Neogene-Recent activity along this structure is responsible for ongoing mountain-building in the broken foreland of the Andes, some 800 km away from the Pacific-South American subduction zone. We characterize Quaternary activity along the SCFS and provide the first numerical age constraints at sites where crystalline rocks of the Sierra Chica range overthrust Quaternary sediments as recent as ~50 ka. Detailed trench logging of the deformation zone defines average slip rates along the SCFS to 0.01–0.36 mm/a over the past ~90 ka. Historical earthquakes of magnitudes ≤7.4 occur along Pampean Range faults without any primary surface ruptures. Thus, evidence for surface ruptures suggests that late Pleistocene slip along the SFCF was likely associated with prehistoric earthquakes with magnitudes >7, although the application of global scaling laws to this tectonic setting tends to underpredict seismogenic potential along the SCFS. Our study aims to highlight the challenges of evaluating the seismic hazard of a fault system that has been active during the late Quaternary, but lack diagnostic geomorphic expression of past surface ruptures. This observation underscores that caution is needed when applying global scaling laws to intracontinental deformation in the broken forelands of subduction zones.}, journal={JOURNAL OF SOUTH AMERICAN EARTH SCIENCES}, author={Costa, Carlos H. and Owen, Lewis A. and Johnson, William J. and Kirby, Eric}, year={2021}, month={Oct} } @article{orr_owen_saha_hammer_caffee_2021, title={Rockwall Slope Erosion in the Northwestern Himalaya}, volume={126}, ISSN={["2169-9011"]}, DOI={10.1029/2020JF005619}, abstractNote={Abstract Rockwall slope erosion is an important component of alpine landscape evolution, yet the role of climate and tectonics in driving this erosion remains unclear. We define the distribution and magnitude of periglacial rockwall slope erosion across 12 catchments in Himachal Pradesh and Jammu and Kashmir in the Himalaya of northern India using cosmogenic 10 Be concentrations in sediment from medial moraines. Beryllium‐10 concentrations range from 0.5 ± 0.04 × 10 4 to 260.0 ± 12.5 × 10 4 at/g SiO 2 , which yield erosion rates between 7.6 ± 1.0 and 0.02 ± 0.004 mm/a. Between ∼0.02 and ∼8 m of rockwall slope erosion would be possible in this setting across a single millennium, and >2 km when extrapolated for the Quaternary period. This erosion affects catchment sediment flux and glacier dynamics, and helps to establish the pace of topographic change at the headwaters of catchments. We combine rockwall erosion records from the Himalaya of Himachal Pradesh, Jammu and Kashmir, and Uttarakhand in India and Baltistan in Pakistan to create a regional erosion data set. Rockwall slope erosion rates progressively decrease with distance north from the Main Central Thrust and into the interior of the orogen. The distribution and magnitude of this erosion is most closely associated with records of Himalayan denudation and rock uplift, where the highest rates of change are recorded in the Greater Himalaya sequences. This suggests that tectonically driven uplift, rather than climate, is a first order control on patterns of rockwall slope erosion in the northwestern Himalaya. Precipitation and temperature would therefore come as secondary controls.}, number={2}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE}, author={Orr, Elizabeth N. and Owen, Lewis A. and Saha, Sourav and Hammer, Sarah J. and Caffee, Marc W.}, year={2021}, month={Feb} } @article{valentino_owen_spotila_cesta_caffee_2021, title={Timing and extent of Late Pleistocene glaciation in the Chugach Mountains, Alaska}, volume={101}, ISSN={["1096-0287"]}, DOI={10.1017/qua.2020.106}, abstractNote={Abstract Geomorphic mapping, landform and sediment analysis, and cosmogenic 10 Be and 36 Cl ages from erratics, moraine boulders, and glacially polished bedrock help define the timing of the Wisconsinan glaciations in the Chugach Mountains of south-central Alaska. The maximum extent of glaciation in the Chugach Mountains during the last glacial period (marine isotope stages [MIS] 5d through 2) occurred at ~50 ka during MIS 3. In the Williwaw Lakes valley and Thompson Pass areas of the Chugach Mountains, moraines date to ~26.7 ± 2.4, 25.4 ± 2.4, 18.8 ± 1.6, 19.3 ± 1.7, and 17.3 ± 1.5 ka, representing times of glacial retreat. These data suggest that glaciers retreated later in the Chugach Mountain than in other regions of Alaska. Reconstructed equilibrium-line altitude depressions range from 400 to 430 m for late Wisconsinan glacial advances in the Chugach Mountains, representing a possible temperature depression of 2.1–2.3°C. These reconstructed temperature depressions suggest that climate was warmer in this part of Alaska than in many other regions throughout Alaska and elsewhere in the world during the global last glacial maximum.}, journal={QUATERNARY RESEARCH}, author={Valentino, Joshua D. and Owen, Lewis A. and Spotila, James A. and Cesta, Jason M. and Caffee, Marc W.}, year={2021}, month={May}, pages={205–224} } @article{bacon_jayko_owen_lindvall_rhodes_schumer_decker_2020, title={A 50,000-year record of lake-level variations and overflow from Owens Lake, eastern California, USA}, volume={238}, ISSN={["0277-3791"]}, DOI={10.1016/j.quascirev.2020.106312}, abstractNote={A continuous lake-level curve was constructed for Owens Lake, eastern California by integrating lake-core data and shoreline geomorphology with new wind-wave and sediment entrainment modeling of lake-core sedimentology. This effort enabled refinement of the overflow history and development of a better understanding of the effects of regional and global climate variability on lake levels of the paleo-Owens River system during the last 50,000 years. The elevations of stratigraphic sites, plus lake bottom and spillway positions were corrected for vertical tectonic deformation using a differential fault-block model to estimate the absolute hydrologic change of the watershed-lake system. New results include 14C dating of mollusk shells in shoreline deposits, plus post-IR-IRSL dating of a suite of five beach ridges and OSL dating of spillway alluvial and deltaic deposits in deep boreholes. Geotechnical data show the overflow area is an entrenched channel that had erodible sills composed of unconsolidated fluvial-deltaic and alluvial sediment at elevations of ∼1113–1165 m above mean sea level. Owens Lake spilled most of the time at or near minimum sill levels, controlled by a bedrock sill at ∼1113 m. Nine major transgressions at ∼40.0, 38.7, 23.3, 19.3, 15.6, 13.8, 12.8, 11.6, and 10.6 ka reached levels ∼10–45 m above the bedrock sill. Several major regressions at or below the bedrock sill from 36.9 to 28.5 ka, and at ∼17.8, 12.9, and 10.4–8.8 ka indicate little to no overflow during these times. The latest period of overflow occurred ∼10–20 m above the bedrock sill from ∼8.4 to 6.4 ka that was followed by closed basin conditions after ∼6.4 ka. Previous lake core age-depth models were revised by accounting for sediment compaction and using no reservoir correction for open basin conditions, thereby reducing discrepancies between Owens Lake shoreline and lake-core proxy records. The integrated analysis provides a continuous 50 ka lake-level record of hydroclimate variability along the south-central Sierra Nevada that is consistent with other shoreline and speleothem records in the southwestern U.S.}, journal={QUATERNARY SCIENCE REVIEWS}, author={Bacon, Steven N. and Jayko, Angela S. and Owen, Lewis A. and Lindvall, Scott C. and Rhodes, Edward J. and Schumer, Rina A. and Decker, David L.}, year={2020}, month={Jun} } @article{saha_owen_orr_caffee_2020, title={A statistical and numerical modeling approach for spatiotemporal reconstruction of glaciations in the Central Asian mountains}, volume={7}, ISSN={["2215-0161"]}, DOI={10.1016/j.mex.2020.100820}, abstractNote={Reconstructing Quaternary regional glaciations throughout the Himalaya, Tibet, and the adjoining mountains in Central Asia is challenging due to geological biases towards limited preservation of glacial deposits and chronological uncertainties. Here, we offer several statistical and mathematical model codes in R, in excel, and in MATLAB useful to develop regional glacial chronostratigraphies, especially in areas with distinct orographically-modulated climate. A complete R code is provided to generate a regional climate map using Cluster Analysis (CA) and Principal Component Analysis (PCA). Additional R codes include reduced chi-squared, Chauvenet's criterion, radial plotter/abanico plot, finite mixture model, and Student's t-test. These methods are useful in reconstructing the timing of local and regional glacial chronologies. An excel code to calculate equilibrium-line altitudes (ELAs) and steps to reconstruct glacier hypsometry are also made available to further aid to our understanding of the extent of paleoglaciations. A MATLAB code of the linear glacier flow model is included to reconstruct paleotemperatures using the length and slope of a glacier during past advances.•R statistical codes can be used/modified without restrictions for other researchers.•Easy steps to calculate ELAs and glacier hypsometry from the same data.•Paleo-temperature reconstruction utilizes already developed glacial chronologies and maps.}, journal={METHODSX}, author={Saha, Sourav and Owen, Lewis A. and Orr, Elizabeth N. and Caffee, Marc W.}, year={2020} } @article{yan_owen_zhang_jiang_zhang_2020, title={Deciphering the evolution and forcing mechanisms of glaciation over the Himalayan-Tibetan orogen during the past 20,000 years}, volume={541}, ISSN={["1385-013X"]}, DOI={10.1016/j.epsl.2020.116295}, abstractNote={Abstract The evolution of past glaciations over the Himalayan-Tibetan orogen and their links with climate change remain elusive, partially owing to the immense scale of the orogen preventing the investigation of all areas. Numerical modeling aids in filling the gaps, verifying the geologic observations, and exploring forcing factors. Based on a transient climate-ice sheet simulation for the past 20 kyr, we demonstrate that the maximum extent of glaciation over the Himalayan-Tibetan orogen occurs around the last glacial maximum (LGM; defined here at ∼20 ka), with expanded ice caps and extensive valley glaciers and being equivalent to a fourfold/sixfold expansion of today's glacier area/volume. The glacier extent shrinks rapidly after the LGM and reaches the minimum around ∼8–7 ka, followed by a slight long-term advancing trend afterwards. Our results suggest a dominant role of summer temperature in controlling the overall trend of glacier response, with precipitation generally modulating the regional extent of glaciation. However, the timing and extent of glaciation in the simulations varies across the Himalayan-Tibetan orogen on millennial timescale, especially between the monsoon-influenced southern and westerly-influenced western parts, further confirming previous speculations based on glacial geologic records. Despite the uncertainties in the simulations and the discrepancy in glaciation between the simulations and the glacial geologic evidence (e.g., 10Be ages), our results provide additional clues on the relationship between climatic change and glacier response. In addition, the modeling aids in advancing our knowledge of the paleoglaciological history of the Himalayan-Tibetan orogen.}, journal={EARTH AND PLANETARY SCIENCE LETTERS}, author={Yan, Qing and Owen, Lewis A. and Zhang, Zhongshi and Jiang, Nanxuan and Zhang, Ran}, year={2020}, month={Jul} } @article{wesnousky_owen_2020, title={Development of the Truckee River terraces on the northeastern flank of the Sierra Nevada}, volume={370}, ISSN={["1872-695X"]}, DOI={10.1016/j.geomorph.2020.107399}, abstractNote={The distribution and elevation of the abandoned strath terraces along the Truckee River in the Carson Range on the eastern flank of the Sierra Nevada are mapped and quantified with measurements from Lidar accompanied by field survey. Each mapped strath terrace is formed by incision into the Hunter Creek Sandstone and deposition of fluvial gravel by the Truckee River. The gravel contains granitic boulders sourced from the glaciated headwaters of the Truckee >20 km upstream from the terraces and display boulders ranging from 4 to 12 m in dimension, in comparison to the <1 m dimension of boulders observed in the bedload of the modern Truckee River. Be-10 terrestrial cosmogenic nuclide (TCN) surface exposure dating places limits on the age distribution of the strath terraces. The terrace sediments are suggested to be glacial outwash deposits, temporally linked with glacial cycles, and to record an average of ~0.3 mm/a tectonic uplift with respect to the Reno Basin over the last ~350 ka. Building upon earlier studies, the observations collected here increase the number of terrace levels previously mapped along the Truckee, provide initial quantitative bounds on the age of their formation, and further point to tectonic uplift as an important component in preserving this most extensive suite of strath terraces along the eastern flank of the Sierra Nevada.}, journal={GEOMORPHOLOGY}, author={Wesnousky, Steven G. and Owen, Lewis A.}, year={2020}, month={Dec} } @article{tian_owen_xu_shen_zhou_figueiredo_2020, title={Geomorphometry and Statistical Analyses of Landslides Triggered by the 2015M(w)7.8 Gorkha Earthquake and theM(w)7.3 Aftershock, Nepal}, volume={8}, ISSN={["2296-6463"]}, DOI={10.3389/feart.2020.572449}, abstractNote={The 2015 Mw 7.8 Gorkha earthquake in Nepal and its Mw 7.3 aftershock triggered at least 22,914 landslides larger than 500 m2 in area and with lengths and widths longer than 20 m. Amongst these landslides, 2,059 had areas >10,000 m2. Analyses of the landslide geometry, using length (L), width (W), height (H, from the crown to toe), reach angle (arctan value of H/L), and aspect ratio (L/W), show that most of the landslides have aspect ratios of 1.6–3.6 and reach angles of 35–45°. The fitting relationship between H and L is H=0.87L-11.11. The steep topography is likely a main factor that controls the landslide runout and planar shape. Using the aspect ratio, these landslides are divided into three geomorphometric categories: LS1 (L/W≤2); LS2 (2}, journal={FRONTIERS IN EARTH SCIENCE}, author={Tian, Yingying and Owen, Lewis A. and Xu, Chong and Shen, Lingling and Zhou, Qing and Figueiredo, Paula Marques}, year={2020}, month={Sep} } @article{booth_gillespie_lancaster_owen_2020, title={Introduction to the 50(th)Anniversary Issue of Quaternary Research}, volume={96}, ISSN={["1096-0287"]}, DOI={10.1017/qua.2020.35}, abstractNote={An abstract is not available for this content. As you have access to this content, full HTML content is provided on this page. A PDF of this content is also available in through the ‘Save PDF’ action button.}, journal={QUATERNARY RESEARCH}, author={Booth, Derek B. and Gillespie, Alan R. and Lancaster, Nicholas and Owen, Lewis A.}, year={2020}, month={Jul}, pages={1–21} } @article{tian_owen_xu_ma_li_xu_figueiredo_kang_guo_wang_et al._2020, title={Landslide development within 3 years after the 2015 M-w 7.8 Gorkha earthquake, Nepal}, volume={17}, ISSN={["1612-5118"]}, url={http://dx.doi.org/10.1007/s10346-020-01366-x}, DOI={10.1007/s10346-020-01366-x}, number={5}, journal={LANDSLIDES}, author={Tian, Yingying and Owen, Lewis A. and Xu, Chong and Ma, Siyuan and Li, Kang and Xu, Xiwei and Figueiredo, Paula Marques and Kang, Wenjun and Guo, Peng and Wang, Siyu and et al.}, year={2020}, month={May}, pages={1251–1267} } @article{seagren_schoenbohm_owen_figueiredo_hammer_rimando_wang_bohon_2020, title={Lithology, topography, and spatial variability of vegetation moderate fluvial erosion in the south-central Andes}, volume={551}, ISSN={["1385-013X"]}, DOI={10.1016/j.epsl.2020.116555}, abstractNote={Understanding how tectonics, climate and lithology interact to control fluvial erosion is complicated because these factors are spatially-variable and they may not be well-represented by mean values. We address these complications using eight new and 54 published 10Be catchment-wide fluvial erosion rates from the south-central Andes. We assess how tectonics, climate, lithology, and topography control erosion through bivariate and multivariate Bayesian regression analysis. We first compare catchment-wide mean values of independent variables compared to other summary statistics and find that metrics that capture extreme values (e.g., 90th percentile) and spatial variability (e.g., 90th minus 10th percentile) produce stronger correlations. This suggests that catchment-wide means may oversimplify the roles of tectonics, climate, and lithology in influencing erosion rates. We find that the overall variability of erosion rates in the south-central Andes is best explained by a combination of lithologic resistance and spatial variability in both vegetation (using the normalized difference vegetation index, NDVI) and topography (using specific stream power). Despite poor bivariate correlations, both lithologic resistance and spatial variability of specific stream power are significant regressors in our multivariate modeling. Lithology influences the relationship (i.e., linearity) between topography and erosion rates. Spatial variability of NDVI produces the strongest correlation with erosion rates of any of the variables we consider. Hence, spatial variability of NDVI both accounts for potential non-uniform vegetation responses to climate and also incorporates the role of both humid climates (high 90th percentile) and large bare regions (low 10th percentile) within a single catchment.}, journal={EARTH AND PLANETARY SCIENCE LETTERS}, author={Seagren, Erin G. and Schoenbohm, Lindsay M. and Owen, Lewis A. and Figueiredo, Paula M. and Hammer, Sarah J. and Rimando, Jeremy M. and Wang, Yang and Bohon, Wendy}, year={2020}, month={Dec} } @article{owen_2020, title={Quaternary Glaciation of the Himalaya and Adjacent Mountains}, ISBN={["978-3-030-29683-4"]}, DOI={10.1007/978-3-030-29684-1_13}, journal={HIMALAYAN WEATHER AND CLIMATE AND THEIR IMPACT ON THE ENVIRONMENT}, author={Owen, Lewis A.}, year={2020}, pages={239–260} } @article{struth_giachetta_willett_owen_teson_2020, title={Quaternary drainage network reorganization in the Colombian Eastern Cordillera plateau}, volume={45}, ISSN={["1096-9837"]}, DOI={10.1002/esp.4846}, abstractNote={Abstract Dramatic drainage reorganization from initial longitudinal to transversal domains has occurred in the Eastern Cordillera of Colombia. We perform a regional analysis of drainage basin geometry and transformed river profiles based on the integral form of the slope‐area scaling, to investigate the dynamic state of drainage networks and to predict the degree of drainage reorganization in this region. We propose a new model of drainage rearrangement for the Eastern Cordillera, based on the analyses of knickpoint distribution, normalized river profiles, landforms characteristic of river capture, erosion rates and palaeodrainage data. We establish that the oldest longitudinal basin captured by the Magdalena River network was the Suárez Basin at ≈409 ka, inferring the timing of abandonment of a river terrace using in situ produced cosmogenic beryllium‐10 ( 10 Be) depth profiles and providing a first estimation of incision rate of 0.07 mm/yr. We integrate published geochronologic data and interpret the last capture of the Sabana de Bogotá, providing a minimum age of the basin opening to the Magdalena drainage at ≈38 ka. Our results suggest that the Magdalena basin Increased its drainage area by integrating the closed basins from the western flank of the Eastern Cordillera. Our study also suggests that the Magdalena basin is an aggressor compared to the basins located in the eastern flank of the orogen and provides a framework for examining drainage reorganization within the Eastern Cordillera and in similar orogenic settings. The results improve our understanding of headward integration of closed basins across orogenic plateaux. © 2020 John Wiley & Sons, Ltd.}, number={8}, journal={EARTH SURFACE PROCESSES AND LANDFORMS}, author={Struth, Lucia and Giachetta, Emanuele and Willett, Sean D. and Owen, Lewis A. and Teson, Eliseo}, year={2020}, month={Jun}, pages={1789–1804} } @article{dietsch_hedrick_owen_caffee_2020, title={Tracking denudation and sediment production and transport with cosmogenic Be-10 in arid, high-altitude Himalayan half-grabens, Zanskar, northern India}, volume={45}, ISSN={["1096-9837"]}, DOI={10.1002/esp.4954}, abstractNote={Abstract Understanding the extent to which local factors, including bedrock and structure, govern catchment denudation in mountainous environments as opposed to broader climate or tectonic patterns provides insight into how landscapes evolve as sediment is generated and transported through them, and whether they have approached steady‐state equilibrium. We measured beryllium‐10 ( 10 Be) concentrations in 21 sediment samples from glaciated footwall and hanging wall catchments, including a set of nested catchments, and 12 bedrock samples in the Puga and Tso Morari half‐grabens located in the high‐elevation, arid Zanskar region of northern India. In the Puga half‐graben where catchments are underlain by quartzo‐feldspathic gneissic bedrock, bedrock along catchment divides is eroding very slowly, about 5 m/Ma, due to extreme aridity and 10 Be concentrations in catchment sediments are the highest (~60–90 × 10 5 atoms/g SiO 2 ) as colluvium accumulates on hillslopes, decoupled from their ephemeral streams. At Puga, 10 Be concentrations and the average erosion rates of a set of six nested catchments demonstrate that catchment denudation is transport‐limited as sediment stagnates on lower slopes before reaching the catchment outlet. In the Tso Morari half‐graben, gneissic bedrock is also eroding very slowly but 10 Be concentrations in sediments in catchments underlain by low grade meta‐sedimentary rocks, are significantly lower (~10–35 × 10 5 atoms/g SiO 2 ). In these arid, high‐elevation environments, 10 Be concentrations in catchment sediments have more to do with bedrock weathering and transport times than steady‐state denudation rates. © 2020 John Wiley & Sons, Ltd.}, number={13}, journal={EARTH SURFACE PROCESSES AND LANDFORMS}, author={Dietsch, Craig and Hedrick, Kathryn and Owen, Lewis A. and Caffee, Marc W.}, year={2020}, month={Oct}, pages={3103–3119} } @article{fame_spotila_owen_shuster_2019, title={Consistent slow exhumation in a late Cenozoic glaciated landscape: The Presidential and Carter ranges of the White Mountains in New Hampshire, USA}, volume={345}, ISSN={["1872-695X"]}, DOI={10.1016/j.geomorph.2019.106842}, abstractNote={Abstract To investigate the ability of the onset of Quaternary glaciations to drive an acceleration in erosion rates we compare short timescale (103–104 yr) erosion rates using the in situ terrestrial cosmogenic nuclide (TCN) 10Be to longer time scale exhumation rates (106–107 yr) using the apatite (U Th)/He method in the Presidential and Carter ranges of the White Mountains in New Hampshire, USA. Our results are generally consistent with but refine previous studies using similar techniques. Resulting (U Th)/He ages and thermal modeling from Mt. Washington in the Presidential Range (n = 4, 91.7 to 117.3 Ma) suggest that exhumation rates from the Late Cretaceous to the present were slow,}, journal={GEOMORPHOLOGY}, author={Fame, Michelle L. and Spotila, James A. and Owen, Lewis A. and Shuster, David L.}, year={2019}, month={Nov} } @article{saha_owen_orr_caffee_2019, title={Cosmogenic Be-10 and equilibrium-line altitude dataset of Holocene glacier advances in the Himalayan-Tibetan orogen}, volume={26}, ISSN={["2352-3409"]}, DOI={10.1016/j.dib.2019.104412}, abstractNote={A comprehensive analysis of the variable temporal and spatial responses of tropical-subtropical high-altitude glaciers to climate change is critical for successful model predictions and environmental risk assessment in the Himalayan-Tibetan orogen. High-frequency Holocene glacier chronostratigraphies are therefore reconstructed in 79 glaciated valleys across the orogen using 519 published and 16 new terrestrial cosmogenic 10Be exposure age dataset. Published 10Be ages are compiled only for moraine boulders (excluding bedrock ages). These ages are recalculated using the latest ICE-D production rate calibration database and the scaling scheme models. Outliers for the individual moraine are detected using the Chauvenet's criterion. In addition, past equilibrium-line altitudes (ELAs) are determined using the area-altitude (AA), area accumulation ratio (AAR), and toe-headwall accumulation ratio (THAR) methods for each glacier advance. The modern maximum elevations of lateral moraines (MELM) are also used to estimate modern ELAs and as an independent check on mean ELAs derived using the above three methods. These data may serve as an essential archive for future studies focusing on the cryospheric and environmental changes in the Himalayan-Tibetan orogen. A more comprehensive analysis of the published and new 10Be ages and ELA results and a list of references are presented in Saha et al. (2019, High-frequency Holocene glacier fluctuations in the Himalayan-Tibetan orogen. Quaternary Science Reviews, 220, 372–400).}, journal={DATA IN BRIEF}, author={Saha, Sourav and Owen, Lewis A. and Orr, Elizabeth N. and Caffee, Marc W.}, year={2019}, month={Oct} } @article{saha_owen_orr_caffee_2019, title={High-frequency Holocene glacier fluctuations in the Himalayan-Tibetan orogen}, volume={220}, ISSN={["0277-3791"]}, DOI={10.1016/j.quascirev.2019.07.021}, abstractNote={Holocene glacial chronostratigraphies in glaciated valleys spread throughout the Himalayan-Tibetan orogen, including the Himalaya, Tibet, Pamir, and Tian Shan, are developed using a landsystems approach, detailed geomorphic mapping, and new and published 10Be surface exposure dating. New studies in the Kulti valley of Lahul and the Parkachik valley of the Nun Kun massif of the Himalaya of northern India define three glacier advances at ∼14.7, 12.2, 0.5 ka, in addition to one historically dated late 19th Century advance in the Kulti valley, and one Late Holocene advance at ∼0.2 ka in the Parkachik valley. Three major climatic groups (subdivided into five climatic zones) are defined across the orogen using Cluster Analysis (CA) and Principal Component Analysis (PCA) to identify glaciated regions with comparable climatic characteristics to evaluate the timing, and extent of Holocene glacier advances across these regions. Our regional analyses across the Himalayan-Tibetan orogen suggest at least one Lateglacial (∼15.3–11.8 ka) and five Himalayan-Tibetan Holocene glacial stages (HTHS) at ∼11.5–9.5, ∼8.8–7.7, ∼7.0–3.2, ∼2.3–1.0, and <1 ka. The extent (amplitude) of glacier advances in 77 glaciated valleys is reconstructed and defined using equilibrium-line altitudes (ELAs). Modern glacier hypsometries are also assessed to help explain the intra-regional variations in glacier amplitudes during each regional glacier advance. A linear inverse glacier flow model is used to decipher the net changes in temperature (ΔT) between periods of reconstructed regional glacier advances in 66 glaciated valleys across different climatic regions throughout the orogen. The 10Be, ELAs, and ΔT data suggest enhanced monsoonal and increased precipitation during the Early Holocene, followed by relative cooling and increased aridity during the Mid- and Late Holocene that influenced glaciation. The sublimation-dominated cold-based glaciers in the northern regions of Himalayan-Tibetan orogen are more affected during these shifts in climate than the temperate glaciers in the south.}, journal={QUATERNARY SCIENCE REVIEWS}, author={Saha, Sourav and Owen, Lewis A. and Orr, Elizabeth N. and Caffee, Marc W.}, year={2019}, month={Sep}, pages={372–400} } @article{orr_owen_saha_caffee_2019, title={Rates of rockwall slope erosion in the upper Bhagirathi catchment, Garhwal Himalaya}, volume={44}, ISSN={["1096-9837"]}, DOI={10.1002/esp.4720}, abstractNote={ABSTRACT Rockwall slope erosion is defined for the upper Bhagirathi catchment using cosmogenic Beryllium‐10 ( 10 Be) concentrations in sediment from medial moraines on Gangotri glacier. Beryllium‐10 concentrations range from 1.1 ± 0.2 to 2.7 ± 0.3 × 10 4 at/g SiO 2 , yielding rockwall slope erosion rates from 2.4 ± 0.4 to 6.9 ± 1.9 mm/a. Slope erosion rates are likely to have varied over space and time and responded to shifts in climate, geomorphic and/or tectonic regime throughout the late Quaternary. Geomorphic and sedimentological analyses confirm that the moraines are predominately composed of rockfall and avalanche debris mobilized from steep relief rockwall slopes via periglacial weathering processes. The glacial rockwall slope erosion affects sediment flux and storage of snow and ice at the catchment head on diurnal to millennial timescales, and more broadly influences catchment configuration and relief, glacier dynamics and microclimates. The slope erosion rates exceed the averaged catchment‐wide and exhumation rates of Bhagirathi and the Garhwal region on geomorphic timescales (10 3 −10 5 years), supporting the view that erosion at the headwaters can outpace the wider catchment. The 10 Be concentrations of medial moraine sediment for the upper Bhagirathi catchment and the catchments of Chhota Shigri in Lahul, northern India and Baltoro glacier in Central Karakoram, Pakistan show a tentative relationship between 10 Be concentration and precipitation. As such there is more rapid glacial rockwall slope erosion in the monsoon‐influenced Lesser and Greater Himalaya compared to the semi‐arid interior of the orogen. Rockwall slope erosion in the three study areas, and more broadly across the northwest Himalaya is likely governed by individual catchment dynamics that vary across space and time. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons, Ltd.}, number={15}, journal={EARTH SURFACE PROCESSES AND LANDFORMS}, author={Orr, Elizabeth N. and Owen, Lewis A. and Saha, Sourav and Caffee, Marc W.}, year={2019}, month={Dec}, pages={3108–3127} }