Abstract Archive Luncheon Schedule Reserve Online Reservation Policy Suggest a Talk


Our Next Luncheon Talk

(11:30 Reception; 11:45 Lunch; 12:15 Talk)


The next talk of the 2018 RMS-SEPM Luncheon Lecture Series will be held on Tuesday, November 26, 2018.

Geochemical and micropaleontological evidence of paleoenvironmental change in the Late Cretaceous Western Interior Seaway from the Niobrara to the Pierre Shale Formation

Kira Timm

DRP Petrographic and Materials Investigations


11:30 Reception, 11:45 Lunch, 12:15 Talk
at the
Wynkoop Brewing Company
1634 18th St., Denver, CO

The cost is $25.00 for current members and $35.00 for non-members ($10 of which pays for an annual RMS-SEPM membership). Unemployed individuals may sign up for lunch for just $10.00. Persons who do not wish to have lunch are welcome for a $10.00 fee. Walk-ins may purchase a lunch for the standard fees ($25.00 or $35.00) although quantities are limited. Walk-ins without a lunch are charged a $10.00 fee.

Please submit reservations by 10:00 a.m., the Friday before the talk.

After the reservation deadline, you may attend the talk for a $10.00 "walk-in" fee. Reservations may be secured online, by e-mail at
or by calling Robin Swank at 720-272-6697


Deposition of the Upper Cretaceous Niobrara Formation and overlying Sharon Springs Member of the Pierre Shale occurred during transgressive phases within the Western Interior Cretaceous (WIC) Seaway, however their respective geochemical and biological differences are significant. The Niobrara Formation is an alternating calcareous chalk/marl system, biologically defined by fecal pellets and robust foraminifers including Heterohelix globulosa, Globigerinelloides ultramicrus, Hedbergella, Gümbelina and two Archaeoglobigerina species. However, the Sharon Springs is primarily argillaceous in composition with lesser amounts of biogenic calcite and silica. Larger foraminifers within the Sharon Springs are primarily arenaceous whereas foraminifers of the same species found in the Niobrara are dwarfed in the Sharon Springs. Dwarfism of foraminifers species and the presence of dispersed diatoms, which flourish in cold waters, indicate a shift in paleocurrents. Deposition of the Niobrara occurred during times where warm Gulfian currents allowed for carbonate production through the Early Campanian. Paleogeographic maps of the Middle Campanian indicate a southerly restriction of the WIC during the time of the southerly Claggett Transgression. The influx of cold, southerly waters resulted in an environment conducive to diatoms and environmentally stressful to foraminifers.

Lithological and geochemical evidence from the Sharon Springs indicates that the cold-water Claggett Transgression resulted in a stratified water column in the middle of the WIC, as well as, increased organic matter production. Petrographic analysis of preserved organic matter show clumped floccules or flattened amalgamations of floccules in laminated facies. While dispersed amorphous organic matter is also present, flocculation had a major influence on organic matter preservation. Two possible depositional mechanisms, each dependent on water density, probably produced these water conditions. If density contrasts existed between the cold water influx and the warm waters present during the deposition of the Niobrara, the cold waters would have progressed along the bottom of the basin leading to upwelling along the basin margin and basin stratification. If no significant density contrast existed, caballing would occur at the mixing front, leading to downwelling, rapid transport of organic matter to the sea floor, better organic matter preservation and basin stratification.


Speaker Biography:

Originally from Kansas City MO, she graduated with her B.Sc. from the University College Cork, in Ireland. She went on to work for the Institute of Geological and Nuclear Sciences in New Zealand while studying at the University of Otago. Her first foray in the petroleum industry was a position as a quantitative interpreter geophysicist with DownUnder GeoSolutions in Perth, Western Australia. After returning to America, she worked with Pason Systems Corp. as lead night geologist providing geosteering support for operations geologists prior to returning to college. Kira Timm recently completed her PhD at the Colorado School of Mines, researching the petroleum geology of the Pierre Shale and Niobrara Formations in the historic Cañon City Embayment. Her research focuses on subsurface, seismic, core, geochemistry and petrographic investigations associated with the petroleum systems.



Speaker List

Click on the talk title for a PDF version of the abstract.


Jan 30

Donna Anderson

Subcrop reinterpretation of the Ordovician Bighorn Dolomite and Devonian Darby Formation, Southwest Wyoming

Feb 27

Larry Rasmussen

Early Triassic Moenkopi Petroleum System of Central Utah

Mar 27

Michael Gardner

Tectonics and Sedimentation of Permian Delaware Basin Deepwater Systems

Apr 24

John Curtis

Time-Lapse Geochemistry of Source-Rock Reservoirs: One Approach & Initial Observations

Jun 5


Aug 28

Justin Birdwell & Ron Johnson

Distribution of mineral phases in the Green River Formation, Piceance Basin, Colorado, Implications for the evolution of Eocene Lake Uinta

Sep 25

Zane Jobe

Applying scaling relationships to enable better reservoir prediction in submarine depositional systems: Bridging the gap between geomorphology and the stratigraphic record

Oct 30

Jeff May

The Sedimentology of Mudrocks: Organisms, Organics & Occasional Occurrences

Nov 27

Kira K. Timm

Geochemical and micropaleontological evidence of paleoenvironmental change in the Late Cretaceous Western Interior Seaway from the Niobrara to the Pierre Shale Formation

Jan 29

William Drake



In order to keep our Luncheon Program solvent and operating on schedule,
the RMS-SEPM Board has adopted the following guidelines for reservations and seating at the Wynkoop:

  • Reservations for this Luncheon Talk will be closed at 10:00am on Friday, before the talk. (No reservations are needed for walk-ins.)