More information coming soon on research relating to the core

Drilling Summary of the DMNH-1 Well located on the Elbert County Fairgrounds in Kiowa, Colorado.

The dust has settled on the fairgrounds in Kiowa, and we are settling into the data analysis phase of the core project. The following summarizes our work during the nearly 30 days of actual coring activity.
We set the shallow steel surface casing on February 24 to ensure that the upper portion of the hole would be stable and provide a secure footing for the coring operations. Coring began the morning of March 1 with a "core breaking" ceremony and ribbon cutting. Students from the Kiowa Elementary School chanted "Drill! Drill! Drill!" from the bleachers as the coring rig started turning to the right.
We acquired 2.5-inch-diameter core in 5-foot segments using a split-tube, wire-line system. The drilling contractor, Layne-Western, was extremely cooperative and helped us keep close track of the footage as we drilled ahead. The drillers worked in 12-hour shifts and we worked in eight-hour shifts as drilling proceeded around the clock.
We drilled ahead for 11 days at a rate of about 132 feet a day until a depth of about 1,460 feet when we paused for a couple of days of rig repair. We returned to work again on March 14 and drilled to 1,880 feet at a rate of about 70 feet a day.
At 1,880 feet, in the upper portion of the Fox Hills sandstone, we had both rig and hole problems that kept us busy for 11 days. We installed steel casing to stabilize the hole and started drilling again on April 1. We had to redrill a portion of the Laramie Formation as we were unable to get the drill bit to the bottom of the earlier hole.
Drilling restarted at 1,800 feet and we proceeded to a final depth of 2,256 feet, drilling at a rate of about 75 feet a day.
Electric logging was conducted by Colog Inc. in a series of three runs. The logging suite consisted of caliper, gamma ray, Spontaneous potential, compensated density and full wave-form sonic logs.
Core recovery of approximately 93 percent was achieved, and the core is archived in sealed plastic sleeves inside PVC pipes at the United States Geologic Survey core repository in Lakewood, Colorado. The well is now completed as a monitoring well in the Denver Aquifer and has a permanently installed piezometer set up beneath a locked steel cap. Elbert County plans to use the well to monitor the level of the aquifer beneath Kiowa as groundwater use increases in the county.

The single largest effort of the research project is to obtain a continuous 2.5-inch-diameter core of the top 2,200 feet of rock in the Denver Basin. Using a cylindrical diamond-coated drill bit, researchers will remove core in 10-foot sections. This core will serve as the database from which the hydrologic, pollen, fission track, and paleomagnetic samples will be taken for analysis. The core will be archived in the public core storage facility at the U.S. Geological Survey in Denver.

Click on the colored layers for more information




D2 Synorogenic Strata:
This layer contains several hundred feet of coarse gravel and sandstone layers derived from the uplifted Rocky Mountains. Environments resembled debris fans east of the modern Andes Mountains in South America. These sediments were deposited in the Eocene Epoch (55-50 m.y.a). Typical fossils include petrified wood, leaves, and rare mammal teeth.

Dawson Arkose:
A sedimentary unit rich in quartz and feldspar typified by outcrops on Dawson Butte and road cuts on Interstate 25 near Larkspur. The Dawson Arkose intertwines with the Denver Formation, making regional mapping difficult. Our terminology ascribes the lower portion of the Dawson Arkose to D1 Synorogenic Strata and the upper portion of it to D2 Synorogenic Strata.

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D1 Synorogenic Strata:
This layer is composed of approximately 1,500 feet of alternating layers of sandstone from ancient river channels and mudstone from ancient flood plains. These layers were deposited during the early part of the uplift of the Front Range by rivers similar to the modern Platte River in northeastern Colorado. D1 Synorogenic Strata are coarse-grained along the Front Range and become fine-grained and coal-like to the east. These sediments were deposited in the Cretaceous Period and Paleocene Epoch (68-56 m.y.a). Typical fossils include petrified wood, leaves, dinosaur bones, and mammal teeth.

A brilliant red clay layer up to 60 feet thick lies on top of the D1 Synorogenic Strata. This red clay formed as ancient soil, similar to modern red soils that have formed in the moist climates of the southeastern United States and the Amazon Basin of Brazil. The presence of the layer suggests that it was exposed and weathered for a very long period of time, perhaps as long as 9 million years. The clay is mined to make bricks.

Denver Formation (Paleocene part):
A sedimentary unit rich in volcanic debris typified by exposures on South Table Mountain west of Denver. Our terminology ascribes the Denver Formation to D1 Synorogenic Strata. Typical fossils include palm and sycamore leaves and mammal teeth. The Castle Rock Rainforest site is located at the top of this unit, and the Denver International Airport fossil site is near its base.

Denver Formation (Cretaceous part):
A sedimentary unit rich in volcanic debris typified by exposures on South Table Mountain west of Denver. Our terminology considers the Denver Formation to be part of the D1 Synorogenic Strata. Typical fossils include palm leaves and dinosaur bones. The Colorado Rockies mascot, Dinger the Dinosaur, was named because home plate at Coors Field is located in the dinosaur-bearing portion of the Denver Formation.

Arapahoe Conglomerate:
A thin layer of gravel, representing the early debris eroded from the uplifting Rocky Mountains. Commonly contains fragments of granite and metamorphic rocks, indicating the streams were eroding the bedrock of the uplifted mountains. Our terminology considers the Arapahoe Formation to be the basal portion of the D1 Synorogenic Strata. Typical fossils include palm leaves and dinosaur bones.

K-T Boundary:
The boundary between the Cretaceous (age of dinosaurs) and the Tertiary (age of mammals) Periods. This interval is often characterized by a half-inch-thick layer of debris that is the fallout from a massive comet or asteroid impact event in Mexico. The impact eject covered Earth with a mantle of dust and probably caused the extinction of the dinosaurs and their world.

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Laramie Formation:
This formation was deposited by low-lying coastal swamps and estuaries along the edge of the Cretaceous sea. Coal seams are common in the lower part of the formation. Typical fossils include palm leaves and dinosaur bones.

Fox Hills Sandstone:
These deposits accumulated at the margin of the retreating Cretaceous Western Interior Seaway, the remains of ancient beaches and shallow marine sand layers. Typical fossils include clams and the burrows of shoreline shrimp.

Pierre Shale:
This mile-thick layer of dark gray mudstone and shale accumulated at the bottom of the Cretaceous Western Interior Seaway. Clams, ammonites, and baculites are the most common fossils. Their distribution tells that for millions of years, this seaway connected the Gulf of Mexico to the Arctic Ocean and covered most of what today is Colorado.

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