Molly O’Halloran

The 

Luke Gezovich

The 

Jake Slawson

jslawson@mines.edu

The 

Bryan McDowell

The Mesaverde Group in western Colorado is a significant natural gas reservoir, producing from isolated-to-amalgamated fluvial sandstones encased in floodplain muds and sourced by laterally- and vertically-adjacent coals. The Mesaverde Group, and the Piceance Basin in general, has been the subject of tight-gas sand research for decades through collaboration between industry, government, and academia. Past research has focused on discrete stratigraphic intervals, small geographic areas, and lacked subsurface-to-outcrop integration. Additionally, previous studies lack robust data sets for subsurface correlation in these laterally heterogeneous reservoirs. The objectives of this study are: (1) constrain and correlate the Williams Fork Formation with a basin-scale stratigraphic framework based on marine transgressions and regressions; (2) characterize fluvial sandbodies at reservoir-scale along the Grand Hogback; and (3) determine allogenic and autogenic controls on sedimentation. 

Maddie Fox

madelinefox@mines.edu

Expected Graduation 2025

Project: Persistent Nature of the Hallstatt Cycle During the Early and Middle Eocene Climatic Optimums

My research explores the role of millennial-scale orbital cycles in driving past rapid climate shifts, providing insights into the mechanisms that influence Earth’s climate system. By analyzing past warming events, I investigate how astronomical forces contribute to climate variability, improving our ability to predict future changes. This work enhances our understanding of the long-term drivers of climate and their potential impacts on modern and future climate dynamics.

Education: 

BSc candidate Colorado School of Mines, Golden, CO 

Publications:

Fox, M., 2025. Persistent Nature of the Hallstatt Cycle during the early and middle Eocene Climatic Optimums. Reuleaux. Colorado School of Mines

Conference abstracts:

Maddie Fox, Jake Slawson, Piret Plink-Bjorklund, 2024. Influence  of Millennial Range Orbital Cycles on Middle Eocene Climatic Optimum  Hyperthermals. ESS Open Archive . AGU2024.
DOI: 10.22541/essoar.170959952.28034671/v1ox .

Maddie Fox, Jake Slawson, Piret Plink-Bjorklund, 2023. nfluence  of Millennial Range Orbital Cycles on Middle Eocene Climatic Optimum  Hyperthermals. AGU2023

Nina Botvin

nbotvin@mines.edu

The 

Maya Maes-Johnson

mmaesjohnson@mines.edu

The 

Eliza Ross

elizaross@mines.edu

The 

Isaac Pope

ipope@mines.edu

The 

Dessy W Sapardina

dsapardi@mymail.mines.edu

Graduated 2023

Project: Supercritical flow signatures and erosional features in active margin basin floor fans

The project aims to test whether the basin-floor fans consist of tabular sheet like beds as predicted by the models or rather consist of amalgamated lenticular bodies that indicate channels or scours. We hypothesize that erosional features due to channelization and supercritical flow are more common in basin-floor fans than predicted by current models. It is still unclear how common are supercritical flow turbidity currents and whether they occur on all types of continental margins. There are also contradicting opinions on whether the supercritical flow turbidity currents mainly occur on slopes or can also be common on basin floor.  The preliminary results from the field work in basin floor fan Juncal formation, California suggest that Froude supercritical flow deposits are common. The erosion surfaces and the association of sandstone prone facies with the erosionally bound deposits suggest that the proportion of channelized deposits is high, and present even in outer-fan setting.

Education: 

PhD Colorado School of Mines 2023

MSc Colorado School of Mines, Golden, CO  

Bachelor of Engineering in Geological Engineering Gadjah Mada University, Yogyakarta, Indonesia

Professional experience: Teaching Assistant for Multidisciplinary Petroleum Design Spring 2019, 2017; 

Field Assistant for Petroleum Engineer Field Camp Summer 2018, 2017

Yoga Teacher 2015 –  2016

ExxonMobil Oil Indonesia as Development Geoscientist 2012 – 2015

ExxonMobil Oil Indonesia as Exploration Geoscientist 2007 – 2015          

Hobbies:Yoga and Mountain Biking

“A geologist by education, a mother by nature and a yoga teacher by passion”

Publications: 

The 20th 2018 International Sedimentological Congress (Quebec, Canada) poster presentation “Title: The Role of Froude Supercritical Flows and Sediment Transport on Deepwater Active Margin Basin Floor-fans, Juncal Formation, California”

Outreach activity:

• Volunteer yoga teacher for Indonesian Community in Colorado

• Women coordinator for Indonesian Muslim Society in Colorado

• Coordinator for Indonesian Fundraising

Mark Hansford

My research is the modern complement to the ancient outcrop work the rest of the research group is working on. It was born out of the observation that some fluvial formations in the rock record contain 90%+ upper flow regime sedimentary structures, leading us to ask the question, “What kind of rivers could make and preserve such deposits?”. For the first phase of my research, I looked at hundreds of rivers around the world and investigated how the discharge regime is controlled by a series of a series of different factors such as climate zones, drainage area, gradient, etc. 

Publications:

Hansford, M., Plink-Bjorklund, P., and Jones, E., 2020. Quantitative analyses of global river discharge variability and hydrograph shape. Invited review. Earth Science Reviews 200, 102977.

Hansford, M., and Plink-Bjorklund, P., 2020. Is there a link between Discharge Variability and Fluvial Fan Formation? Geology 48, 952-956.

B.S. in Geology from Wheaton College.

PhD Colorado School of Mines 2020

Intern at Royal Dutch Shell summer 2018 and will be returning for a second internship summer 2019.

Haipeng Li

The goal of this project is to answer at least in part the following question: how can we interpret the ancient sedimentary record with more confidence and less biases? This is a big question and can be further investigated from three different aspects.

Publications:

Li, H., & Plink-Bjorklund, P. (2019). Applying information theory and Bayesian inference to paleoenvironmental interpretation. Geophysical Research Letters, 46, 14477– 14485.

Ph.D. in Geology, Colorado School of Mines 2020

M.S. in Sedimentology, China University of Geosciences, Beijing, 2015

B.S. in Geology, China University of Petroleum, Beijing, 2012

Anything fun:

• Deep interest in human psychology, particularly in the mechanism of decision making and misjudgment
• Deep interest in etymology, and origin and development of scientific ideas
• A dear wife, a cute sister, and two loving parent

1. Haipeng Li and Piret Plink-Bjorklund. The effect of river discharge variability on environmental signal propagation: an experimental study in 2019 AAPG ACE, May 19-May 21
2. Haipeng Li and Piret Plink-Bjorklund. Green River Formation fluvial macroforms (?): are supercritical flow structures scale-invariant? in RioMar annual meeting, Houston, December 2018 (Poster)
3. Haipeng Li and Piret Plink-Bjorklund. River responses to floods: Sediment mobility during major storms in RioMar annual meeting, Houston, December 2018 (Poster)
4. Haipeng Li and Piret Plink-Bjorklund. Autogenic Deposits as A Potential Recorder of High-Frequency Signals: The Role of Autogenic Processes Revisited in 2017 AGU Fall Meeting, New Orleans, December 15, 2017 (Poster)

Kristi Zellman

My doctorate thesis research is focused on Paleogene deposits in the San Juan Basin (SJB), New Mexico.  The SJB is thought to preserve the southwestern-most terrestrial sedimentary record of late Paleocene and early Eocene in North America.  In recent years, Paleocene-Eocene (P-E) boundary deposits have been a focus of research due to the discovery of globally-distributed anomalous sedimentation events coincident with periods of geologically abrupt global warming (hyperthermals), including the Paleocene-Eocene Thermal Maximum (PETM).  Nevertheless, the SJB was previously overlooked as a possible dataset for this research, in part due to a long-standing suggestion that the P-E boundary falls within an unconformity.   However, similarities between the SJB deposits and anomalous sedimentation events in other terrestrial basins associated with early-Eocene hyperthermals have led myself and a few other researchers to question the chronological placement of the unconformity.  My research is part of an ongoing investigation of these deposits with goals to (1) refine the chronostratigraphy of the P-E boundary and determine whether records of early-Eocene hyperthermals, including the Paleocene-Eocene Thermal Maximum (PETM) are preserved, and (2) describe climatic conditions and their impact on fluvial sedimentation.

Publications:

Zellman, K. L., P. Plink‐Björklund, and Spangler, L., 2024, Progradational‐to‐retrogradational styles of Palaeogene fluvial fan successions in the San Juan Basin, New Mexico: Basin research, v. 36, no. 1, doi:10.1111/bre.12823.

Zellmann, K., Plink-Bjorklund, P., and Fricke, H., 2020. Testing hypotheses on precipitation variability signatures in the river and floodplain deposits of the Paleogene San Juan Basin, New Mexico. Journal of Sedimentary Research 90, 1770-1801.

I am a Colorado native, originally from Boulder.  I received my B.A. in Anthropology from Colorado State University and my M.S. in Environmental Science from the University of Colorado at Denver.  I also hold a graduate-level GIS Certificate from the University of Denver.  My past work experience is diverse and includes archaeology, GIS product management, marketing and human resources.  In 2010, I decided to pursue a career in geology with the U.S. Geological Survey (USGS).  Over the last eight years I have progressed from a Physical Science Technician to a Geologist and have worked on a variety of research projects and USGS map publications.  My work at the USGS inspired me to take my education to the next level, which is what brought me to the Colorado School of Mines.  I have two young children (boys!) and a very supportive husband.  Balancing family, work, and a Ph.D program has not always been easy, but I enjoy the challenge.  In my spare time, I enjoying being in the mountains with my family and introducing our children to the adventures they have to offer.

Andrew Heger

My research focuses on forebulge and backbulge deposition zones in both modern and ancient foreland basin systems (FBS).  The forebulge depozone is fairly well represented in literature, whereas the backbulge has received far less attention. The aim of this research is to provide both a historical perspective on the forebulge-backbulge research, and provide an update on the current state of knowledge associated with these parts of the FBS. Presently, I’m working on documenting the criteria for how these areas have been recognized and what evidence has been used to support their recognition.

MS Geology: Colorado School of Mines, 2016

PhD Geology: Current Student

Work Experience:

2010-present: Oil and gas industry

Personal:

Besides spending time with my family and friends, I enjoy organizing & leading multi-day river trips across the western U.S.

Matthew Belobraydic

Michael Genecov

Facies and sedimentary characteristics of tide-dominated and -influenced deltas vary significantly. This leads to the question of how to accurately recognize one in the field. My aim is to gather sedimentary characteristic data for each subenvironment on as many interpreted tide-dominated and -influenced deltas as possible. I then analyze the dataset looking for common characteristics and learning where the knowledge gaps are. Observations suggest, while there is significant inconsistency in the language used to describe these deltas there are also many common sedimentary characteristics that are used to justify significant tidal action.

Education:

B.S. in Geology from Southern Methodist University ‘14

MSc in Geology from Colorado School of Mines 2024

Hobbies: Rock Climbing, Mountaineering, Skiing, Carpentry, Travel

Michael Peffer

Leland Sprangler

Recently, Leland has been investigating rapid climate change during the Paleocene-Eocene Thermal Maximum, and its signatures left in the rock record worldwide. This research aims to provide a comprehensive overview of existing PETM literature, a categorization of PETM climate types, and a visual display of these climate types to identify trends and gaps in the dataset.

He has had the opportunity to assist PhD candidate Kristine Zellman with her PETM work in the San Juan Basin, and is looking to continue with his own studies in graduate school. Currently, Leland is writing his own paper to synthesize his investigations in to PETM climate types. 

B.S. in Geological Engineering (Exploration) 2019

Leland is a senior undergraduate student interested in sedimentology, paleoclimate, and stratigraphy. He is looking foreword to interning with EOG Resources as a geology intern starting in the summer of 2019, and is looking to start a M.S in the fall of 2019. Previously, Leland has worked as a geology museum tour guide, and as a geological engineering intern with the Colorado Department of Transportation. In his copious spare time, Leland is an avid snowboarder, mountain biker, and fly-fisherman. He also enjoys playing blues guitar with his band.

Julia Payne

Xuan Yang

Xuan Yang received his bachelor degree in 2012 from Southwest Petroleum University in China. He has worked in the Sixth Oil Production Plant of PetroChina Daqing Oilfield Company for 1 year. He continued his research and received the master degree in 2016 from China University of Petroleum (Beijing). He had an internship in Research Institute of Petroleum Exploration and Development in PetroChina Huabei Oilfield Company from 2014 to 2016. He continued his research and studies at China University of Petroleum (Beijing) as a PhD candidate since 2016. He is actively working on sequence stratigraphy, sedimentology and reservoir analysis of clastic rocks.