Late-Holocene seasonal moisture variability: Range Creek Canyon, Utah, USA

The Holocene · 2020 · 2 citations

• Geology
• Physical geography
• Oceanography

A 3300 year-long reconstruction of paleoenvironmental moisture conditions was constructed from a sediment core from North Gate Bog (NGB) in the northern section of Range Creek Canyon within the Colorado Plateau. The methods used to analyze the record include loss on ignition (LOI), magnetic susceptibility (MS), elemental analysis with X-ray fluorescence (XRF), charcoal influx, isotopic analysis, elemental ratios and pollen percentages, influx, and ratios. This study adds two new insights to the paleoenvironmental record of the northern section of the Colorado Plateau. First, four climatic zones were established. Zone 1 (3300–2750 cal yr BP) had 100-year wet to dry variations with droughts recorded from 3300–3200, 3000–2900, and 2800–2700 cal yr BP. Zone 2 (2750–1600 cal yr BP) had an overall dry period with an 800-year transition to increased warmth and winter moisture. Zone 3 (1600–850 cal yr BP) had an overall warm, wet, summer precipitation climate conducive to the establishment of Zea Mays and Pinus edulis, two staple foods of the Fremont culture. The Medieval Climate Anomaly (MCA) registered warm and wet in this part of the Colorado Plateau. Zone 4 (850–0 cal yr BP) had a sharp transition to a drier climate from 850 to 400 cal yr BP. During the Little Ice Age (LIA), wetter climate taxon increases such as Artemisia, Cyperaceae, and Pinus edulis. The second overall finding in this study was that NGB was a place of human activity including Fremont farming. The identification of a Zea mays pollen grain confirms the archeological presumptions that this higher elevation site was used to farm corn along with other sites in Range Creek Canyon (RCC). The post Fremont occupation period was marked by a sharp increase in organic material and a return of pinyon-juniper woodlands.

Age control for the Lake Bottom oxbow in the Dolores River watershed of eastern Utah, USA

Quaternary International · 2020 · 1 citations

• Geology
• Geochemistry
• Geomorphology

A 1,500-year synthesis of wildfire activity stratified by elevation from the U.S. Rocky Mountains

Quaternary International · 2017-07-10 · 18 citations

A 14,000-year record of fire, climate, and vegetation from the Bear River Range, southeast Idaho, USA

The Holocene · 2016-01-11 · 8 citations

The vegetation and fire history of the Bear River Range (BRR), Southeast Idaho has been reconstructed from pollen, plant macrofossils, and macroscopic charcoal from lacustrine sediments. Overall, the BRR record shows independent responses of vegetation and fire regime to climate variation. The reconstructions suggest strong seasonal bias from the proxies evaluated, with the pollen record most sensitive to insolation-driven summer temperature trends, and the charcoal-based fire record more sensitive to winter snowpack variability. Together, the proxies suggest that the early Holocene experienced larger than average snowpacks but very warm summers. Warmer than modern summer temperatures were maintained through much of the mid-Holocene, but snowpacks decreased dramatically, creating the most extreme xeric conditions in the Holocene between ~7100 and 6000 BP. After 6000 BP, summers began to show a consistent cooling trend. Winter precipitation remained low until ~4400 BP, after which higher than average snowpacks are indicated until 2000 BP. Pollen and charcoal data relationships at ~8800 BP and from 1800 to 800 BP suggest periods with anomalously wet summers that created a unique fire regime during those intervals.

Complementary seasonal bias in records of Holocene paleoclimate, Bear River Range, Southeast Idaho

Quaternary International · 2015-11-01

A speleothem record of Holocene paleoclimate from the northern Wasatch Mountains, southeast Idaho, USA

Quaternary International · 2013-03-23 · 48 citations

A season specific paleoclimate record from a northern Wasatch Mountains speleothem and linkages to the pacific

Quaternary International · 2013-09-21

Complementary Seasonally Biased Records of Holocene Paleoclimates of the Bear River Range, Utah and Idaho

Digital Commons - USU (Utah State University) · 2012-01-01

Knowledge of long-term hydroclimatic variability in the West provides important contextual information for modern water resource management and helps provide predictive insights as modern climate change alters hydrologic patterns. Unfortunately, many paleoclimate or paleohydrologic indicators are strongly biased toward conditions in one certain season. This potential disconnect between proxy indicator biases and actual seasonal climate patterns can diminish the the utility of paleoclimate records, or lead to false inferences. We present two independent records of paleoenvironmental conditions from essentially the same location in the Bear River Range to try to elucidate season-specific conditions through the Holocene. One record is a speleothem stable isotope record from Minnetonka Cave, and the other is a lacustrine pollen/charcoal record from Bloomington Canyon. Highlights of our findings are that the Early Holocene, while effectively dry for vegetative growth, saw larger than average snowpacks. Peak summer temperatures occurred from 11-9ka, but peak hydrologic drought did not occur until 7.5-6ka do to the offsetting effects of increased winter precipitation from 11-7.5ka. Both vegetative and hydrologic variability increased after 4ka, but especially after 2.5ka. The midieval climate anomaly was characterized by anomalously warm wet summers.

Organic, elemental, and geochemical contributions to lake sediment deposits during severe spruce beetle (Dendroctonus rufipennis) disturbances

Forest Ecology and Management · 2012-11-28 · 20 citations

A speleothem record of climate variability over the last millennium in the northern Wasatch Mountains, southeast Idaho

AGUFM · 2009-12-01