(GROUPED BY LOCATION)
CALIFORNIA and TIBET
Deciphering the mechanisms of forearc basin formation by engaging undergraduate and middle school students in field and analytical geoscience research (NSF EAR CAREER #1942460)
From Dr. Orme’s NSF abstract: Forearc basins develop oceanward of the magmatic arc of a convergent margin and trap sediment in deep troughs. These basins can exist for tens to hundreds of millions of years, serving as a long-term record of past Earth environments, processes, climate regimes, and life. They also host natural resources such as oil and gas. The goal of this research is to determine the origin of forearc basins by investigating the relationship between the types of rocks that underlie the basin and the sedimentary rocks preserved within the basin.
The research and education components of this project focus on increasing diversity in, and accessibility to, the geosciences through sustained engagement with underrepresented undergraduate and graduate students and middle school girls from rural communities in Montana. Students will participate in research design, field and laboratory work, and national conferences. Students also will help lead a STEM workshop for middle school girls focused on rocks and minerals from the western U.S. and Tibet.
Current Students: Natalee Weis, MS Student
Previous students: Mariah Romero, PhD, MSU 2022
Basal age and provenance of the Great Valley forearc basin, California
In collaboration with Dr. Kathleen Surpless
The preservation of the Great Valley forearc has led to over 60 years of research devoted to understanding its evolution, as well as the deep-water sedimentologic processes related to the development of vast petroleum and natural gas reservoirs (e.g., Graham, 1987). Recent advances in geochronologic dating and applications to provenance studies have shed light on sediment dispersal and infilling patterns of the Great Valley forearc (DeGraaff-Surpless et al, 2002; Dumitru et al., 2013; Sharman et al., 2014). However, the application of such tools, has also called into question
previously understood stratigraphic age constraints on the timing of initial basin sedimentation (Surpless et al. 2006). More than 10 years after this provocative study, the age and stratigraphic architecture of the basal Great Valley forearc remains unclear. The objectives of this study are to study the “birth” of a forearc basin through determining the depositional age and stratigraphic architecture of the basal Great Valley forearc basin.
Sedimentary facies and structural evolution of the Yarlung Suture Zone
The Yarlung suture zone in southern Tibet contains several sedimentary successions that record sedimentation along the southern margin of Asia and leading edge of India prior to and following the onset of continent-continent collision. Our current work documents the discovery of two previously undocumented siliciclastic sedimentary successions, which we mapped and measured during our 2018 field season.
Orme, D.A., Laskowski, A.K., Zilinsky, M.F.*, Chao, W., Guo, X., Cai, F., Ding, L., (2020) Sedimentology and provenance of newly identified Upper Cretaceous trench-basin strata, Dênggar, southern Tibet: Implications for development of the Eurasian margin prior to India-Asia collision, Basin Research, doi.org/10.1111/bre.12521.
Laskowski, A.K., Orme, D.A., Cai, F., Ding, L., (2019) The Ancestral Lhasa River: A Late Cretaceous trans-arc river that drained the Proto-Tibetan Plateau, Geology, doi:10.1130/G46823.1/
Impact of the Plio-Pleistocene Transition on Provenance and Sediment Routing from the Himalaya to the Deep-Sea Bengal Fan (NSF-GEO-NERC 2026870)
In collaboration with Dr. Michael Blum, Dr. Yani Najman, Dr. James Gleason and Dr. Kurt Sundell
Current Student: Spencer Dixon
From our NSF abstract: The Himalayas represent the largest mountain chain on Earth, and reside mostly in Nepal, India, Pakistan and China. The Himalayas began rising many millions of years ago when India collided with Asia, which changed Earth?s climate, altered ocean circulation and chemistry, and impacted the course of biological evolution. Erosion of the Himalayas resulted in deposition of the largest pile of sediment on the planet in the Bay of Bengal, the deep-sea Bengal Fan. Within this sediment record lies the history of the Himalayas, the now eroded Mt. Everests of the past, buried under sediment of the continental shelf and the deepest parts of the Indian Ocean. In 2015, a multi-national expedition on the JOIDES Resolution, a specially designed scientific drilling ship, recovered ~1.5 miles of sediment cores that contains this record.
New research will use these sediments to trace the history of Himalayan erosion and how two of the world?s largest rivers, the Ganges and Brahmaputra, delivered it to the Bay of Bengal over the last 3-5 million years. Giant mountain ranges like the Himalayas are a rarity through geologic history, but without the Himalayas there are no drenching Asian monsoons, no fertile floodplains or aquifers, no ancient Indus Civilization, and no Mt. Everests in that part of the world. The results of this research will therefore tell us about climate change, landscape evolution, and how one of the world’s most densely populated areas came to be as seen today. Understanding the past in this way can help us better understand the future for the 10% of the world’s population that lives under the influence of this incredible geographic feature. This project also supports international collaboration between scientists and students from several universities in the U.S., the U.K. and several Asian countries where field work will be conducted.
Reconstructing the missing record of late Proterozoic tectonism along the western margin of Laurentia using deep-time thermochronology (NSF EAR # 2140482)
Actively recruiting a PhD student for FALL 2023. Please reach out to Dr. Orme for more information.
From our NSF abstract: Unconformities, which are abundant in the rock record, are traditionally viewed as unfillable gaps in the rock record of Earth’s history. However, the thermal imprint of sedimentary cover on the basement rocks that underlie many unconformities provides a rich archive of the otherwise inaccessible parts of a continent’s tectonic history. This record is now accessible due to recent conceptual and analytical advances in low-temperature thermochronology. The primary objective of this study is to contribute to these advances by targeting a critical gap in knowledge about Laurentian tectonics, the breakup of supercontinent Rodinia, while establishing an approach to deep-time thermochronology that can document Precambrian tectonic activity in regions that also experienced significant Phanerozoic mountain building. This study will sample along a 700-kilometer-long segment of western Laurentia’s rifted margin, targeting basement rocks directly below the Great Unconformity and using four chronometers to produce holistic tectonothermal histories to fill a billion-year gap in the rock record. This study will demonstrate how deep time thermochronology can provide a new perspective on the geometry and tectonic evolution of western Laurentia’s rifted margin, where much or all of the sedimentary record of Neoproterozoic tectonism is missing. This capability will be tested by (1) establishing a clear link between extant Neoproterozoic sedimentary rocks and Neoproterozoic tectonothermal events in the Uinta Mountains, (2) documenting the Proterozoic thermal histories of basement blocks with no overlying Neoproterozoic strata in the Teton Range and southwestern Montana, and (3) quantifying intra-mountain range variability of Proterozoic thermal histories to evaluate the sampling spatial resolution necessary for extracting meaningful tectonic information from the deep-time thermochronologic record.
Extracting t-T histories from highly variable zircon He datasets
Student: Chance Ronemus, MS Student, MSU
In collaboration with Dr. William Guenthner
Recent advances in the understanding of He diffusivity in zircon provide new opportunities to extract thermal histories from regions with which experienced multiple and prolonged thermal events using the zircon He method. We are currently working on new thermochronologic constraints on the time-Temperature history of the northern Rocky Mountain region in Wyoming.
Check out our article in EPSL: Orme et al. 2016
EDMAP 2020-2021: Geologic map of Melrose and Wickiup Creek 7.5′ quadrangles, Highland Mountains, southwest Montana: Refining the structure between Proterozoic and Paleozoic stratigraphy exposed at Camp Creek
Student: Chance Ronemus, MS Student, MSU
From the EDMAP proposal: The primary goal of this project is to create a high-quality, 1:24,000 scale geologic map of the eastern and western halves of the Melrose and Wickiup Creek 7.5’ quadrangles respectively, located in the southeastern Highland Mountains, ~40 km SSW of Butte, Montana. This project aims to further the mission of the National Geologic Mapping Program by characterizing the geologic framework of southwestern Montana at a high-resolution. In this region, geology and societal interests are intimately linked; portions of the proposed map area are within the Moose Creek, Melrose, and Rochester historic mining districts, which have produced millions of dollars in revenue from the production of gold, lead, copper, silver, and other economic minerals.
Sedimentary architecture and provenance of the Mesoproterozoic Lahood Conglomerate
Student: Christopher Baird, MS Student, MSU
In collaboration with Dr. Matthew Malkowski
The Mesoproterozoic LaHood formation outcrops as a narrow belt of coarse grained siliclastics between the Bridger Range and Highlands Mountains, southwest Montana. The depositional environment of these facies is debated, with end-members suggesting entirely subaqueous deposition by turbidity and debris flows or a single alluvial fan-delta-submarine fan source-to-sink system. Chris’ work combines field based sedimentologic and stratigraphic observation with petrographic and geochronologic analyses to reconstruct the depositional environments, provenance and tectonic setting of the LaHood Formation.