Session topics, workshops, and field trips
The Forum will have poster and oral presentations in the following topical sessions. The abstract deadline is May 16, and you must submit your abstract online. The session topics will be as follows:
- Quantifying rates of slip
- Localization processes within the lithosphere
- Faulting and fluid flow
- Cordilleran tectonics
- Teaching about time and scale
- Development of tectonic microstructures
- Cutting edge research in structural geology, geophysics, geochemistry, and tectonics. Abstracts submitted in this category will be presented as posters distributed among the sessions above.
The technical session chairs will select a small number of abstracts for oral presentations among those submitted to the first six sessions listed above. All other submissions will be presented as posters, including all those submitted under the general topic of research in structural geology, geophysics, geochemistry, and tectonics.
Special session for grad students and post docs: preparing for an academic career in the geosciences
- What: Are you interested in a future faculty position? Come to this informal "speed dating" session where you will have a chance to talk with current faculty about what it's like to teach and do research at a wide variety of academic institutions and get advice on how to prepare for an academic job search.
- When: Monday evening from 7:30-9:30, location TBA.
- No registration required.
Optional, taking place before and after the Forum (July 30 and 31; August 4 and 5). You must register for these when you register for the Forum (opens in a new window). The registration deadline is May 16.
- July 30: Highlights of the Franciscan. Leaders: David Bero, Sonoma State; Christie Rowe & Samantha Carruthers, McGill University. Limited to 22 participants. Start time 8 am.
This trip will visit two world-famous highlights of the Franciscan Complex in Marin County, the Marin Headlands Terrane and Ring Mountain, to discuss the initiation of subduction in the Jurassic and accretion through the Cretaceous. The Marin Headlands Terrane consists of imbricate thrust sheets of basalt, chert and greywacke and is known for the extraordinary exposure of chaotic chevron folds in the chert sequences. The structural base of the terrane is the Point Bonita Seamount, where well-preserved pillows, dykes and sills are visible on a short walk to the Point Bonita Lighthouse that offers stunning views of the Golden Gate. We will visit the Rodeo Cove Thrust exposures on Cronkite Beach.
Ring Mountain is home to the most diverse collection of high pressure, low temperature metamorphic rocks anywhere in the Franciscan Complex. Eclogite-, blueschist-, amphibolite- and greenschist-facies metabasite blocks occur in a serpentinite matrix mélange below a harzburgite thrust sheet that caps the mountain. The exotic block mélange was thrust over a sliver of blueschist-grade broken formation (including clastics, metabasalts and chert), which was in turn thrust over folded prehnite-pumpellyite-facies sandstones and shales. This is a unique opportunity to hike through the structural evolution and metamorphic inversion that characterizes the subduction complex.
- July 30: Eastern Northern Coast Ranges (Wine Country Geology). Leader: Eldridge Moores, UC Davis. Limited to 22 participants. Start time 8 am.
This one-day field trip plans to traverse parts of the northern Coast Ranges east of Rohnert Park in Sonoma Valley, Napa Valley, and eastward. We will travel through Sonoma Valley, the Mayacamas mountains to the east, Napa Valley, and the Vaca Mountains, between Napa Valley and the Sacramento Valley. We will examine exposures of the three main units of the California active continental margin–the Great Valley sequence, Coast Range Ophiolite, and Franciscan complex, younger volcanic rocks, active branches of the San Andreas fault system, and possible evidence for active folding and thrust faulting.The trip will be by van, with stops at roadcuts. Walking will be minimal. Climate varies considerably from west to east in the northern Coast Ranges, from cool and maritime near the coast (temperature ~ 20-30°C) to dry and, in the summer, hot (temperature 30-40°C). Please bring: sunscreen, hat, light jacket, water, light walking shoes, TP, etc.
- July 31: Active faulting in the Napa Valley. Leaders: Alex Morelan and Mike Oskin, UC Davis. Limited to 22 participants. Start time 8 am.
The Mw 6.0 South Napa earthquake occurred on 24 August 2014 along the southern extent of the West Napa fault. Despite its relatively small moment magnitude, the earthquake produced 14 km of surface rupture, with a maximum coseismic right-lateral slip of ~30 cm (right-lateral) in the Browns Valley neighborhood of Napa, 10 km north of the epicenter in American Canyon. The surface rupture on the West Napa fault strikes north-northeast, bending to the north at its northern end, terminating in a series of small stepovers. This field trip will visit sites along the surface rupture where tectonic slip from the 2014 event may still be preserved. Most evidence of the surface rupture has been destroyed by surface processes and infrastructure repair. Additionally, we will visit sites in northern Napa Valley, where new evidence indicates that the West Napa fault transitions to reverse sense and has produced both single-event and composite fault scarps, and folded alluvial fan deposits.
- July 31: Inherited structural complexity and active deformation in the eastern Coast Ranges (Eastern Franciscan and CRF). Leaders: Ben Melosh and Bob McLaughlin, USGS. Limited to 22 participants. Start time 8 am.
This trip will focus on the structural and stratigraphic interfaces between the lower Great Valley Group, the Coast Range ophiolite and parts of the Franciscan Eastern belt in the Cache Creek – Lake Berryessa area of the eastern Coast Ranges. We will explore the structural complexity and juxtaposition of these different terranes and discuss the interaction of older and modern styles of deformation in the area. We will visit outcrops of different terranes and structural domains in the GVG and CRO to key our eyes into the rocks. We will then focus on large-scale relations of terrane boundaries and geometries of active deformation in the region. We are particularly interested in spurring discussions of the influence of fundamental Mesozoic and early Tertiary bedrock structure on the geometry and kinematics of modern deformation.
- August 4: Introduction to the Strabo Data System. Leaders: Basil Tikoff & Randy Williams, University of Wisconsin Limited to 10 participants. Start time 8 am.
This 1 day field trip will introduce participants to the Strabo Data system and mobile application using actual outcrop examples.The Strabo Data System is a digital database system for structural geology and tectonics (SGT) data that is designed to facilitate digital recording and sharing of data within our community. The Strabo mobile application (iOS and Android devices) is being developed in conjunction with this database system, and allows quantification and tracking of hierarchical and spatial relations between structures at all scales in the field. We will provide a brief introduction to the underlying database structure with case studies from localities where the system has been deployed. We will then travel to Pt. Reyes where participants will be able to use the Strabo mobile application (iPads will be provided) to map and collect field data from numerous faults exposed in the area.
- August 4: Northern San Andreas Fault Deformation, Point Arena. Leader: Matty Mookerjee, Sonoma State. Limited to 22 participants. Start time 8 am.
During this field trip, we will travel to the northern-most exposure of San Andres Fault related deformation exposed on land, near Point Arena, CA. At the Moat-Creek and Schooner Gulch Beach locations, we will look at deformation within the Neogene Schooner Gulch, Galloway, and Point Arena Formations. The deformation here is interpreted as being the result of either blind or poorly exposed imbricate thrust faults associated with the transpressional deformation along the SAF. There are abundant examples of off-fault-related folding (e.g., small-scale fault-bend-folds, fault-propagation-folds) as well as small-scale faulting structures (wedge faults and normal faults). Large-scale concretions (≈2m in diameter) become involved in the deformation in interesting ways. In addition to the tectonic deformation, we will examine evidence for paleoseismicity in the form of soft sediment deformation and clastic dikes. On our way to Point Arena, we will stop by Shell Beach to see a classic locality of Franciscan geology.
- August 5: Brewschist IV: Franciscan Complex and Brewpubs of Sonoma County. Leader: John Wakabayashi. Limited to 22 participants. Start time 8 am.
This trip views rocks near Lake Sonoma and on the Sonoma Coast that bear on a variety of subduction interface processes, such as high-pressure, low-temperature (including blueschist facies) metamorphism, exhumation of such rocks, different styles of subduction megathrust slip accommodation, and the origin of mélanges. We will see exceptional exposures of siliciclastic and serpentinite mélange matrix, with features suggesting sedimentary incorporation of exotic blocks, including rocks exhibiting higher metamorphic grade than the matrix. We will visit blueschist facies sandstones associated with black fault rocks and imbrication of ocean plate stratigraphy (OPS). The fault rocks and imbricated OPS may represent different styles of megathrust slip accommodation. We will also see rocks representing the petrologic Moho (ultramafic cumulates over mantle tectonite) of the Coast Range ophiolite that represents the upper plate "tectonic lid" over the Franciscan. Small breweries of Sonoma County have been at the cutting edge of the USA craft brewing revolution, and will visit two en route (Bear Republic Brewing Company for lunch, and Stumptown Brewing Company), and finish the trip with dinner at the famed Russian River Brewing Company. This is why we call this the Brewschist Tour.
- August 5: NEW TRIP! Active Tectonics of the North Coast. Leaders: Carol Prentice and Steve DeLong (USGS). Limited to 22 participants. Start time 8 am.
This field trip will focus on the geomorphology of the San Andreas Fault and uplifted marine terraces along the Gualala Block, between Fort Ross and Point Arena, CA. We will trace the surface rupture associated with the 1906 San Francisco earthquake, discuss fault slip rate and timing of pre-historic earthquakes, and explore the use of marine terraces to estimate uplift rates and horizontal fault slip rates. In addition, we will investigate variations in uplift rate across the fault and along the coast, as evidenced by overall topography, marine terrace elevations, and cosmogenic radionuclide studies.
Optional, taking place before and after the Forum (July 30 and 31; August 4). You must register for these when you register for the Forum (opens in a new window). The registration deadline is May 16.
- July 30: Introduction to Electron Backscatter Diffraction (EBSD): sample preparation and analysis. Leader: Matty Mookerjee. Limited to 6 participants. Start time 10 am.
This course is designed to be a very basic introduction to analyzing crystallographic fabrics via Electron Backscatter Diffraction (EBSD), specifically for individuals who have no previous experience with EBSD. During the morning, we will prepare some quartz-rich thin sections (some of which can be provided by the course participants) for EBSD analysis using an automated grinder/polisher (Buehler EcoMet/AutoMet) and vibratory polisher (Buehler VibroMet). In the afternoon, we will analyze some of those thin sections on the Scanning Electron Microscope via EBSD and EDS (electron dispersive spectroscopy) and produce both crystallographic and chemistry maps, respectively.
- July 30 - half day workshop, afternoon: New Methods for Creating Admissible Cross Sections. Leader: Kurt Burmeister and Scott Giorgis. Limited to 24 participants. Start time 1 pm.
This workshop will present a modified version of the classic Busk (1929) and Kink (Suppe, 1989) methods that provides students with a quick and effective approach for constructing geologically admissible cross sections of strata involved in parallel folds. This technique combines the mechanical control of traditional methods with the speed of freehand sketching. In addition to classroom and laboratory applications, this method is particularly well suited for courses that require students to construct cross sections from their own geologic map data. Students in these courses are commonly encouraged to use their field data to sketch subsurface projections. Unfortunately, while constructing cross sections with freehand projections can be a quick and effective method for resolving working hypotheses, this technique requires a level of experience and insight that most students are still developing. Without these skills, students must rely upon the mechanically rigorous methods (e.g., Busk/Arc and Kink methods) if they are to construct geologically admissible cross sections from their data. These formal methods can be cumbersome and often require specialized drafting tools. Furthermore, even the slightest of inconsistencies in a student's field data will often lead to frustrating complications when using traditional cross section construction methods. This informal workshop will provide participants with hands-on opportunities explore this new method and consider ways it can be implemented into existing courses. No prior experience with the Busk and/or Kink methods is needed.
- July 31: Statistical Treatment of Structural Geology Data. Leaders: Josh Davis, Sarah Titus, and Basil Tikoff. Limited to 24 participants. Start time 8 am.
Data sets in structural geology and tectonics frequently include geometric data types such as directions, orientations, and ellipsoids. Statistics offers various techniques for understanding the uncertainty inherent in such data, but these techniques are not well known in geology. This short course describes a few basic statistical tools: plotting, averaging, regression, and inference (confidence regions and hypothesis tests). First, we apply these tools to directional data, which include fault poles, lineations, paleomagnetic directions, etc. The second part of the course describes orientation statistics, which treats foliation-lineation pairs, folds, slickensides, crystallographic orientations, and other orientational data. Finally, we introduce ellipsoid statistics, which is applicable to the analysis of ellipsoids, including deformed clasts, SPO, and AMS. No prior experience in statistics is needed. Participants will need their own laptop computers. In the days before the short course, we will send instructions for installing the necessary free software.
- August 4 - morning workshop with optional afternoon session: Teaching Structural Geology: use of tablet-based apps for mapping in our undergraduate structure courses. Leader: Larry Malinconico. Limited to 20 participants. Start time 9 am. Optional afternoon session 1-3 pm.
This workshop will explore the use of tablet applications for digital field mapping. In the morning session we will try some of the different applications listed below, with the option to test the apps in the field in the early afternoon.
Compasses: GeoCompass 2, Lambert, Field Compass
Vertical measurements: Theodolite
Mapping Programs: Clino, GeoFieldBook
Stratigraphic programs: Stratlogger
While several iPads will be available for use, participants are encouraged to bring their own iPads with Apps installed. Additionally, participants will be encouraged to share their favorite geologic field apps with the group.
- August 4: Analysis, statistics, and presentation of geological spherical directional data using Orient. Leader: Fred Vollmer. Limited to 14 participants. Start time 8 am.
Orient is free software in development since 1986 for the analysis of directional data using spherical projections and related techniques. Orient 3 was released in 2015 with numerous enhancements, it is user-friendly for students, but designed for professionals. Following a "quick start" to illustrate ease of use, interactive features, and graphical output, and an introduction to data analysis and spherical projections, a variety of data sets (bedding, foliations, joints, crystallographic axes, paleomagnetic vectors, earthquake epicenters, and fault slickensides) will be used to explore more advanced topics, including contour plots, coordinate rotations, data visualization, confidence regions, spherical distributions, bootstrap statistics, kinematic analysis of fault data, and automated structural domain analysis of refolded folds. Additional topics may include small circle confidence cones (conical folds), cluster analysis (fracture sets and fold limbs), circular histograms, conical data (drill cores), UTM coordinate conversion, locating data on web-based maps, and plotting in Google Earth. The workshop will be informal, allowing discussion and hands-on analysis. Participants are encouraged to bring their own data sets for analysis. Computers will be available, although laptops with Windows, Macintosh, or Linux systems may be used. Participants may opt to attend only the morning session to accommodate travel plans.