Tag Archive for: Stromatolites

ENERGY & MINERALS

Microbialites

Microbialites are organic sedimentary lake or marine deposits that can indicate distinctive types of oil potential and reservoirs. Microbialites take several forms: thinly layered (stromatolites), clotted (thrombolites), spherical (oncolites), and precipitated from mineral-rich springs (tufa or travertine). The hypersaline environment of Utah’s Great Salt Lake is ideal for forming microbial mats, stromatolites, thrombolites, and other porous carbonate structures. Core samples from other areas in the state such as the Eocene-age Green River Formation display ancient examples of microbialites




Microbialites in Utah


Great Salt Lake is ideal for stromatolite formation and is home to some of the most extensive reefs of living stromatolites on Earth. The lake’s briny environment precludes organisms that would ordinarily graze or browse on nutritious stromatolites or burrow and bore into them. Additionally, a lack of animals minimizes stirring of sediments from the lake bed that would otherwise blanket stromatolites from sunlight. The absence of plants and scarcity of other algae on the lake floor also reduce competition for nutrients and space. They are most observable when lake level is near average elevation (4,200 feet) or lower and after planktonic algae have been grazed out by brine shrimp, making the water more transparent.

The lacustrine Eocene-age Green River Formation in the Uinta Basin, Utah, contains excellent examples of microbial carbonates—stromatolites, thrombolites, and grainstones—which can serve as analogues for highly productive nonmarine microbial reservoirs worldwide. The West Willow Creek field produces oil from a small microbial mound within the Green River Formation—the only such known field in the Uinta Basin. Microbialite heads often consist of stromatolitic crusts with thrombolitic internal characteristics. Oncolites are another significant component to the microbial system. The entire Skyline 16, Federal No. 15-24B from the West Willow Creek field, and other cores containing microbial carbonates, are available for examination at the Utah Core Research Center.


Antelope Island Flyover


The shallow waters of Bridger Bay, on the northwestern tip of Antelope Island in the Great Salt Lake, support extensive microbial carbonate formation, especially in the north-northeast portion of the bay near Egg Island. Lake levels in the fall of 2014 were near 60-year lows, giving unprecedented access to the microbial structures. Characterizing the microbialites of Bridger Bay can inform interpretations of similar deposits in the ancient rock record, including potential petroleum reservoirs.


Publications, Abstracts, and Presentations

Microbial Carbonate Reservoirs and Analogs from Utah
Thomas C. Chidsey, Jr, David E. Eby, Michael D. Vanden Berg, and Douglas A. Sprinkel
UGS Special Study 168

PDF Publication

Unexpected abundance and diversity of phototrophs in mats from morphologically variable microbialites in Great Salt Lake, Utah
Mert Kanik, Mason Munro-Ehrlich, Maria Clara Fernandes-Martins, Devon Payne, Kathryn Gianoulias, Lisa Keller, Alexander Kubacki, Melody R. Lindsay, Bonnie K. Baxter, Michael D. Vanden Berg, Daniel R. Colman, Eric S. Boyd

PDF Publication

Domes, Rings, Ridges, and Polygons: Characteristics of Microbialites from Utah’s Great Salt Lake
Michael D. Vanden Berg, The Sedimentary Record, March 2019

PDF Publication

Petrography and characterization of microbial carbonates and associated facies from modern Great Salt Lake and Uinta Basin’s Eocene Green River Formation in Utah, USA 
from Microbial Carbonates in Space and Time: Implications for Global Exploration and Production

Download Abstract

Characterization of Microbialites in Bridger Bay, Antelope Island, Great Salt Lake, Utah
Michael D, Vanden Berg, Thomas C. Chidsey, Jr., Davis E. Eby, and Wayne Kelln
Presented at the International Limnogeology Congress 2015, June 15-19, 2015, Reno, NV.

Poster

Marine Microbial Carbonate Facies, Fabrics, and Petroleum Reservoirs in Utah
by David E. Eby, Thomas C. Chidsey, Jr., and Douglas A. Sprinkel
Presented at the Rocky Mountain/Cordilleran Section Meeting of Geological Society of America, May 18-20, 2014, Bozeman, MT.

Poster

Modern and Ancient Microbial Carbonates in Utah, U.S.A.: Examples from Great Salt Lake and the Uinta Basin’s Tertiary (Eocene) Green River Formation

by Thomas C. Chidsey, Jr., David E. Eby, Michael D. Vanden Berg
Presented at The Geological Society (London) Microbial Carbonates in Time and Space: Implications for Global Exploration and Production Symposium, June 19-20, 2013, London, England.

Poster

Microbial Carbonates in Cores from the Tertiary (Eocene) Green River Formation, Uinta Basin, Utah, U.S.A.: Analogues for Non-Marine Microbialite Oil Reservoirs Worldwide
by Michael D. Vanden Berg, David E. Eby, Thomas C. Chidsey, Jr., and Michael D. Laine
Presented at The Geological Society (London) Microbial Carbonates in Time and Space: Implications for Global Exploration and Production Symposium, June 19-20, 2013, London, England.

Poster

Microbial Carbonates from Core and Outcrop, Tertiary (Eocene) Green River Formation, Uinta Basin, Utah
by David E. Eby, Thomas C. Chidsey, Jr., Michael D. Vanden Berg, and Michael D. Laine
Presented at the American Association of Petroleum Geologists Annual Convention, April 22-25, 2012, Long Beach, CA.

Poster

OLYMPUS DIGITAL CAMERA

eastern Uinta Basin, Uintah County, Utah
Photographer: Michael Vanden Berg; © 2014

Algal stromatolites from the Green River Formation, eastern Uinta Basin, Uintah County.

Is that coral in Great Salt Lake? Great Salt Lake was lower than average last summer, exposing coral-like structures that are usually beneath water. Maybe some of you saw them!

Great Salt Lake has reef-like structures that resemble coral and are often called coral, yet they are not true coral. Algae build bulbous sedimentary rock structures known by various names: algal bioherms and stromatolites are two of the most common.

Read more about bioherms and stromatolites in our “Glad You Asked” article HERE

Chalk Knolls, Tule Valley, Millard County, Utah
Stefan Kirby

Stromatolites, precipitated by algae in reef-like columns, are common in the Cambrian-age Hellnmaria Member of the Notch Peak Formation, Chalk Knolls, Tule Valley, Millard County

Tag Archive for: Stromatolites