Title: Submarine Volcanic Eruptions

Abstract: Submarine volcanic eruptions are poorly documented because they are largely hidden beneath the ocean surface and most of what they erupt is deposited on the sea floor. As a consequence they are not well understood, including the processes that drive eruptions and the fate of erupted materials. I will describe some of what we are learning from studies of the Havre eruption, the Hunga eruption (the highest eruption we ever recorded), and a recent IODP Expedition to the Hellenic volcanic arc.

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Title: Progress on a Deep Learning Enhanced Earthquake Catalog for Northern California.

Abstract: Developing enhanced earthquake catalogs is essential for nearly all aspects of seismology, including understanding foreshock and aftershock behavior, imaging the Earth structure, and identifying active faults. Here we present progress on a deep learning enhanced catalog for northern California from 2023, where we use the PhaseNet picker and the GENIE phase association algorithm to develop a catalog of ~4.2x more earthquakes than the routine NCEDC catalog. The set of seismic stations we use to develop this catalog is highly variable, with hundreds of stations throughout the bay area, and far fewer stations throughout the central valley and Sierras, as well as dense local networks at Parkfield and Geysers. Despite this heterogeneity, we find GENIE appears effective at associating picks reliably across the full spatial domain, spanning from south of Parkfield and Ridgecrest, to north of the Mendocino Triple Junction, and from the west coast into western Nevada. The model achieves this by using graph convolutions to combine information from nearby stations, which allows it to identify reliable signatures of events even for small earthquakes that only show up on a fraction of the network. Our results are further verified by confirming that ~95% of all reported NCEDC earthquakes are re-detected, and the spatial locations of new events improves the detected seismicity rate primarily at the expected fault locations. The Gutenberg-Richter distribution of the new catalog is consistent with the reference NCEDC catalog, but extends to a lower magnitude of completeness, and double difference relocation further refines the expression of faults and quarries throughout the region.

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Title: So You're Thinking About A Career in Economic Geology and Mineral Exploration...

Abstract:

A career in the search for ore deposits is one of the most rewarding ways to make a living.  Far more than just a job, you will surround yourself with people who share your passion for discovery.

In this day and age, a career in economic geology and mineral exploration might encompass a vast array of subjects and activities, including classical field geology, petrography, metallurgy, geotechnical, ore control, drilling, 3D modeling and resource estimation, environmental and permitting, social engineering, logistics, project and people management, marketing or running a company.  You might find yourself anywhere in the world, using planes, helicopters, trucks, 4-wheelers or mules to get there.  If travel is your thing, you might be the first person on the ground in a remote village, or living in a camp, in a tent, or a seaside resort.  You might be logging core, mapping an ore deposit, planning and laying out drill sites to test your model, compiling and analyzing data, giving presentations, going to conferences, building geological and resource models, working with engineers and metallurgists, supervising environmental studies, writing technical reports and a million other things.

A successful career in economic geology and mineral exploration takes flexibility, teamwork, an open mind, an ability to analyze large data sets, taking risks, learning from others and a willingness to embrace all aspects of the search for an economic deposit.

Here’s my story, and some helpful hints on how to jumpstart your career.

Title:  Drilling Volcanic Rifted Margins to Understand Large Igneous Provinces and Associated Global Warming.

Abstract: Continental breakup is a rare, but fundamental Earth event driven by massive internal forces. The splitting of Europe from Greenland some 56 million years ago was likely triggered by hot material rising from the deep mantle, forming a large igneous province. The breakup magmatism was associated with a global warming and extinction event, the Paleocene-Eocene Thermal Maximum (PETM). IODP Expedition 396 successfully drilled 20 holes on the mid-Norwegian continental margin to better understand continental breakup processes and to test the hypothesis that associated voluminous magmatism triggered the PETM. Hole locations were carefully selected on conventional and high-resolution 3D seismic data. In total, > 4 km of sediments and volcanic rocks were drilled, recovering 2 km of core. The expedition recovered the first sub-basalt rocks on the Norwegian margin, documenting the presence of granite and inter-basalt sandstones on the Kolga High. We also cored three different seaward dipping reflectors (SDR) facies units on the Vøring Margin, representing basaltic lava flows emplaced in sub-aerial, coastal, and deep marine environments, respectively. An Outer High named Eldhø, was sampled at the termination of the Inner SDR and recovered spectacular pillow basalt units. The PETM interval was cored at the ten Modgunn Arch and Mimir High holes. The Modgunn holes drilled into the upper part of a hydrothermal vent complex. High-resolution palynology and isotope geochemistry document that the hydrothermal venting took place near the start of the PETM, supporting the hypothesis that the global warming event was triggered by shallow-water eruption of greenhouse gases formed by heating of organic-rich sediments intruded by magmatic sills.
In conclusion, scientific drilling has provided essential data to document how the Earth’s internal processes have influenced the environment and life in deep time. To understand the environmental changes in the future, it is critical to keep on drilling the ocean basins to test new hypotheses and to discover our geological past.

Title:Tectonic Inversion and Buttressing: A Case for Cenozoic Contraction in Northern Oman

Abstract: 

The geology of northern Oman and eastern Arabia is distinctive because of the emplacement of the Semail Ophiolite onto the stable Arabia platform in the late Cretaceous followed by the later development of the Jebal Akhdar and Saih Haitat domes. East of Muscat, the Wadi Kabir Fault forms an important structure along which the northern edge of the Saih Hatat domes was unroofed.  In the Bandar Jissah area, Triassic carbonates occur in the footwall of the NNE-dipping Wadi Kabir Fault while rocks of the Semail Ophiolite, newly discovered rocks of the metamorphic sole, and a sequence of Paleogene-Eocene sedimentary rocks crop out in the footwall.  Some workers posit that the Wadi Kabir and associated faults form basin-bounding normal faults for the Bandar Jissah rift basin and that folds in the hanging wall cover sequence are the product of rollover during extension and basin formation.

However, our detailed mapping and kinematic analysis illustrates that folds in the hanging wall are contractional structures that formed due to tectonic inversion along the Wadi Kabir and other faults.  The overall shortening is modest (~10%) and primarily confined to the hanging wall rocks, consistent with buttressing against mechanically rigid rocks in the footwall of the Wadi Kabir Fault.  These structures require an interval of N-S directed shortening in northern Oman that post-dates the deposition of mid-Eocene marine sediments in the Seeb Formation. The Wadi Kabir Fault also has localized zones of listwaenite preserved in its damage zone that is derived from ophiolitic rocks in the hanging wall. K-Ar age dating of gouge along the Wadi Kabir Fault yields ages of ~90 Ma and 58 ± 2 Ma, consistent with a long history of slip.  Collectively, the Wadi Kabir Fault is a long-lived structure that’s experienced multiple episodes of extensional and contractional slip since the Cretaceous.