Climate & Earth Science

Rock and sediment layers preserve fossils. They also preserve stories about the timing and environment those organisms lived and died in. The results of this research give crucial context to the thousands of fossils that remain underground. What we learn about the past and current environments of Tule Springs helps us to protect them and adapt to the effects of climate change and urban development. The fossils and geologic features at Tule Springs represent resources that Nuwu/Nuwuvi ancestors interacted with thousands of years ago that continue into the present and future.

 

 

Related Research from Tule Springs Fossil Beds
Climate & Earth Science

Explore published research about ancient climate records, groundwater deposits, radiometric dating techniques, and more from Tule Springs Fossil Beds National Monument. 

Source: Data Store Collection 9638. To search for additional information, visit the Data Store.

 

U.S. Geological Survey Research Geologists observe and collect samples from a historic 1963 trench at Tule Springs in 2024.

NPS Photo | L. Parry

Geologic Mapping & Stratigraphy

Geologists learn how to read the clues left behind in the rock record to understand environments that are no longer around. By observing the rocks and sediments at Tule Springs, we know that groundwater springs flowed here for over 500,000 years, creating a lush landscape.

Detailed geologic mapping and stratigraphy (describing and characterizing sedimentary rock layers) were first published from the Tule Springs area in the 1960s; although initial surveys were conducted in 1903 by the U.S. Geological Survey. The Las Vegas Formation was named by Chester Longwell and othersin 1965 to describe the fossil-bearing sedimentary deposits exposed in and around what is now Tule Springs Fossil Beds National Monument. Following the Tule Springs Expedition of 1962-1963, geologist C. Vance Haynes Jr. further described subunits of the Las Vegas Formation. This expedition used bulldozers to carve deep trenches into the sediment to better observe layers below the surface. After more than a decade of research, scientists from the U.S. Geological Survey published the formalized, up-to-date framework for the Las Vegas Formation in 2018. Today, the Las Vegas Formation consists of 17 geologic units (members X, A, B, D, and E and attendant beds in members B, D, and E). These sediments date from approximately 573,000 to 8,530 years ago.

Tule Springs Fossil Beds works closely with researchers from the U.S. Geological Survey Geosciences and Environmental Change Science Center. Learn more about this program...

 

Charcoal and carbon-rich sediments are collected for radiocarbon dating. These materials originate from ancient trees and wetland plants.

NPS Photo | L. Parry

Geochronology

Geologists use various methods to determine the absolute ages of sedimentary rock layers. Time is an important variable in scientific research and allows you to measure patterns, change, or stability. One of the most important methods for determining the ages of Pleistocene, or Ice Age sedimentary layers is radiocarbon dating. Radiocarbon dating – sometimes called carbon-14 dating – allows us to obtain ages for ancient organic materials as old as about 60,000 years. The method is so valuable for geology, paleontology, archeology and many other scientific fields that its developer was awarded a Nobel Prize in 1960. When it came time in the 1960s to test this method for the first time in a large-scale field study, a committee of scientists selected the area that is now Tule Springs Fossil Beds National Monument and Ice Age Fossils State Park. Radiocarbon dating is still an important tool today to understand and better refine the anicent history of Tule Springs Fossil Beds. Learn more...
For layers and materials older than 60,000 years, scientists use a method called luminescence dating. Luminescence dating determines how long ago minerals were last exposed to the heat and light of the sun.

 

A spring-fed stream frozen in time. Tufa formations at Tule Springs Fossil Beds follow the paths of ancient streams across the landscape from 10,600 years ago.

NPS Photo

Climate, Past & Present

The desert around us today is dry and rugged—but this wasn’t always the case. During the last Ice Age, water and plants trapped windblown sand and mud. Over time, layer by layer, these sediments formed the deposits of the Las Vegas Formation. These deposits are known as groundwater discharge deposits. The terrestrial climate record at Tule Springs Fossil Beds captures how local desert wetlands responded in sync with global climate changes for tens of thousands of years, even on the submillenial scale.
Melted snow and rainfall on the surrounding mountain ranges seeped through the porous rock to slowly travel down to underground aquifers. Water that is stored underground could flow to the surface by way of faults, which are breaks in the Earth’s crust. During more wet periods, underground aquifers were fuller. During drier interglacial periods, wetlands shrank or dried up at Tule Springs. Geologists study modern desert wetlands and compare their observations to the rock record. This helps us recognize specific spring environments from the past. Wetlands finally disappeared from the Tule Springs landscape about 8,500 years ago--however, other desert springs remain throughout the Southwest. These remaining desert wetlands are important harbingers of environmental change. Tule Springs Fossil Beds works closely with researchers from the U.S. Geological Survey Geosciences and Environmental Change Science Center. Learn more about this program...

The National Park Service Climate Change Response Program advances efforts to address the effects of climate change across the breadth of the National Park System. The Program works collaboratively to support parks through technical expertise and research, guidance and training, project and planning support, and provision of communication products. Learn more about the National Park Service Climate Change Response Program...