QRC members lead and participate in a wide range of disciplinary and interdisciplinary research projects from the study of past earth climates and glaciations to shifts in the geographic distributions and evolution of vegetation and faunal communities, to the evolution and dispersals of the genus Homo and the increasing scales of human modification of earth environments through the Holocene. QRC provides a venue for meeting and collaborating with scholars across Quaternary disciplines. We are also fortunate to be able to provide seed funding and small grants for member research projects. We are especially happy to support grad student and junior scholar research activities, much of which leads to larger, external funding from agencies like the National Science Foundation.
Investigating Strike-Slip Faulting in the Hyper Arid Core of the Atacama Desert, Northern Chile
Abstract: The Salar Grande Fault (SGF) is a dextral-oblique fault system within the northern segment of the Atacama Fault Zone (AFZ), in Northern Chile. The study area is immersed in hyper-arid desert conditions (< 2 mm/year rainfall), with excellent surface preservation markers indicating strike-slip fault motion. The region sits within one of the most active subduction zones in the world, where future magnitude 9 earthquakes from the megathrust and tsunami waves up to 30 m are expected to impact the coastal towns. Reconstructing the landscape evolution of the SGF is essential to understand the role of crustal faults in subduction zone settings and the interaction between deeper tectonics and surface processes.
This QRC fund supports two methods to provide Quaternary and Cenozoic evolution data to the study area.
Optical Luminiscence Dating (OSL) techniques working with the USGS Luminescence Laboratory Facilities: We took several samples from fluvial deposits, alluvial fans and fault scarps, to date humid periods and potential paleoseismic activity in the study area. These ages contribute to build a better paleoclimatic record of the study area.
Pilot study of thermochronology in apatites with the CU-Trail Facilities: we took 8 samples from a transect up to the top of the mountains of the study area. Our goal is to reveal the exhumation history of the mountain range and the role of the SGF in the uplift of the region.
This is an essential part of my research and Ph.D. dissertation at UW and these project are both collaborations between the ESS Department and other institutions like CU Boulder and the USGS. We hope to present these results in conferences and publish at least one peer-reviewed publication from the data.
A search for pre-LGM megaflood sedimentation in Cascadia Basin
Abstract: Marine sediments along the Cascadia margin are likely to contain continuous, long-term records of marine and continental change in the Pacific Northwest over the last several million years. While glaciations, floods, and erosion have reworked the terrestrial record, many marine sites had continuous deposition over this timespan. Such sites are potential archives of oceanographic history, meltwater influx, density-current processes, subduction zone tectonics, and landscape evolution. We propose to study two legacy sediment cores from Cascadia Basin, focusing on depositional chronology and tracers of sediment provenance. The two cores, Deep Sea Drilling Program (DSDP) Sites 174 and 175 are by far the deepest cores from this region, and thus unique in their recovery of sediment spanning multiple glacial-interglacial cycles. This work is a first step towards finding and developing long-term records of megafloods down the Columbia River and understanding Cascadia Basin sedimentation throughout the Pleistocene.
The Future of the Past: Capturing a 5000 year record of Human‐>Environmental variability on the North Coast of Alaska
Abstract: QRC funds provide travel support to take a small group of UW graduate students to Barrow, Alaska in July 2016 to participate in a rescue excavation of the Walakpa archaeological site. This project will support the strategic sampling of a repository of archaeological and environmental information spanning the past 3500‐5000 years at a location of critical importance for understanding the cultural change and movements of Arctic people through late Holocene. The work will preserve vital data and give UW students potential future research projects. The site is full of well‐preserved organic artifacts (marine and land hunting implements, boat and sled parts, food processing and clothes making tools, clothing, baskets, toys, jewelry), house foundations, and burials that the Inupiat community of Barrow wants moved to safer ground. The site includes paleo-environmental data on changes in marine and terrestrial ecology, sea ice history and polar climate from the mid to late Holocene, but the site is highly vulnerable to erosion and may not last another warm winter. The site has the potential to reveal new insights about the development of Arctic maritime adaptations, human responses to climate changes, the causes of both the pre-Dorset and Thule (ancestral Inuit) migrations from Alaska across the Eastern High Arctic (ca 2200 B.C. and 1200 A.D., respectively).
For the QRC and UW, this rescue operation presents a unique opportunity to further the Arctic legacy that was initiated by QRC founders Linc Washburn, Steve Porter, and others and that manifests today in the QRC engagement in the Future of Ice Initiative. Perhaps most importantly, the chance to introduce a new generation of students to the Arctic at a site that will generate significant research opportunities is especially valuable when Arctic researchers are few and the Arctic is losing archaeological sites at an unprecedented rate.
C14 dating of mangrove peat cores from Seram and Ujir Islands, Indonesia
Abstract: We will obtain radiocarbon dating of mangrove peat cores collected on a recent field trip by Peter Lape to Eastern Indonesia (Seram and Ujir Islands). This collaborative fieldwork was supported by grants to Lape from National Geographic and Mellon, with matching funds from the QRC. These funds supported fieldwork but only minimal post fieldwork analyses. The mangrove cores were collected for analysis by the Sachs lab for paleorainfall signatures. This data will be useful for both archaeological and paleoclimate research. It will allow Lape to better understand agricultural conditions for people living in Eastern Indonesia, a central question of his archaeological research. It will allow Sachs to better understand how local rainfall in Eastern Indonesia, a crucial region in the western Pacific that is influenced by monsoon systems, is linked to regional and global scale climate fluctuations.
Radiometric Dating of Lake Sediment Cores from the South Pacific Convergence Zone for Late Holocene Paleoclimatology
Abstract: The South Pacific Convergence Zone (SPCZ) is the Southern Hemisphere’s most prominent rain feature, however a full understanding of its structure and behavior is lacking, predictions of how it might respond to future warming are uncertain, and few studies have addressed its behavior in the past. Tropical atmospheric circulation is a major driver of Earth’s climate yet little is known about the extent of natural variability during the late Holocene including the Medieval Warm Period (MWP) (950-1250 AD) and the Little Ice Age (LIA) (1400-1800 AD). Organic geochemistry is a promising tool for improving our understanding of the SPCZ. To determine past variations we use hydrogen isotope ratios (2H/1H) of specific lipids from lake sediments collected in 4 target regions of the SPCZ with different average modern rainfall rates (including the Solomon Islands, Vanuatu, Wallis, and Fiji). Lipid 2H/1H measurements can reveal past change because environmental water 2H/1H is linked to fluxes of water though the hydrologic cycle and lipid 2H/1H is almost perfectly correlated with source water 2H/1H. Since growth rate, growth stage, salinity, and irradiance can influence lipid 2H/1H fractionation, duplicate records from unique freshwater lakes in each distinct region of the SPCZ will be developed. However, it is crucial to continue to develop age models for these sediment cores in order to properly interpret the climate records we generate. The objective of this project is to improve preliminary age models of several sediment cores from the SPCZ region. Completely dating (with 6-10 14C and 6-10 210Pb samples for a profile) cores that currently have sound preliminary age models is our priority. Developing age models for currently undated cores will be pursued as needed from the most promising sites to ensure duplicate records from each target region are completed. Generating records from 2 unique lakes from each of the 4 regions is the best way to ensure our interpretation of the climate signal is not influenced by local parameters (i.e. growth and light). Due to high accumulation rates in many of the SPCZ lake sites, age models based solely on 14C dates are not appropriate for many our cores, which have a significant amount of sediment that accumulated after 1900 AD. Therefore, in addition to using 14C dates, sediment chronologies will be augmented by modeling the decay profiles of unsupported lead-210 (210Pb) in the upper ~20-100 cm of sediment. Typically lipid 2H/1H analysis can yield qualitative information about wetter versus drier periods. Once strong age models are obtained and compound specific 2H/1H measurements are complete, this project will result in the 1st quantitative late Holocene hydroclimate reconstructions from this understudied region of the maritime tropics. In order to generate quantitative records of rainfall rates in the SPCZ region we have analyzed surface sediment samples from 18 lakes in 13 locations and found that the isotopic composition of the biomarker dinosterol is well correlated with modern rainfall rate. Generating records from multiple distinct sites in and around the SPCZ will allow us to characterize how this major precipitation feature changed in the past.
Report: Read the report here and the published manuscript here.
Distal and ultra-distal tephra layers as a dating tool in various fields of the Quaternary studies with special focus on Kamchatka and Kuril Islands
Abstract: Dated and geochemically fingerprinted tephra layers serve as excellent marker horizons which directly link disparate depositional successions. These layers can be used for dating paleoclimate changes, paleoseismic events and archaeological horizons as well as for compiling a record of hazardous volcanic eruptions. In the frames of this project we are planning to work on two papers. The first one will focus on the Holocene tephrochronological framework for a geodynamically active Kamchatsky Peninsula in Eastern Kamchatka (NW Pacific), where tephra layers permit deciphering of the complicated history of environmental change and natural hazards. The second paper will complement the first one focusing on the Late Glacial-Holocene environmental change in the same area (with Dr. Pendea, Lakehead University, Toronto, Canada). The work will be carried out together with Professor Joanne (Jody) Bourgeois. In addition, I will give a talk on the use of tephrochronology for the Quaternary studies in western Beringia, and hopefully will have a chance to interact with the ESS and QRC students.
Abstract: From dating of lake sediments from a QRC trip to NE India, it is clear there were historical floods (e.g., 750 AD), and from the Chinese dating it is clear there were several earlier ones during the Pleistocene. In 2004, samples were collected that allowed dating the times during which there may have been major ice dams across the Yarlong Tsangpo, but most of these samples have not been analyzed as the chronology of glacial damming was outside of the scope of the project that supported the fieldwork. The QRC trip to NE India collected samples of flood deposits that have been dated to the time of the most recent Tibetan lake sediments. This project proposed to date the remaining samples from Tibet using cosmic ray exposure analysis with Be-10 for boulders sampled from moraines and OSL for sands from lake sediment exposures. These data will provide a much-enlarged chronology of ancient glacial river damming (and thus outburst flooding) events that will be of great use for an ongoing project (Huntington/Montgomery) dating the Tsangpo flood deposits in NE India. The goal is to combine our existing dates on Tibetan lake sediments and dated moraine dams collected by Gillespie, Montgomery, and Henck, with downstream flood deposits collected by Larson, Montgomery, and Huntington to write a group QRC paper that ties these observations together (through the dates) and sets the stage for further work in the region.
Abstract: The Salar Grande Fault (SGF) is a dextral-oblique fault system within the northern segment of the Atacama Fault Zone (AFZ), in Northern Chile. The study area is immersed in hyper-arid desert conditions (< 2 mm/year rainfall), with excellent surface preservation markers indicating strike-slip fault motion. The region sits within one of the most active subduction zones in the world, where future magnitude 9 earthquakes from the megathrust and tsunami waves up to 30 m are expected to impact the coastal towns. Reconstructing the landscape evolution of the SGF is essential to understand the role of crustal faults in subduction zone settings and the interaction between deeper tectonics and surface processes.