The Hrafnfjordur central volcano, Northwestern Iceland
What: Field and laboratory research on Tertiary volcanic rocks in the Westfjords region of northwestern Iceland. The main research focus is the Hrafnfjordur central volcano, where we expect to encounter both basalts and rhyolites, and likely some intermediates. The project will consist of three weeks of field study in Iceland, and one week of laboratory follow-up at The College of Wooster (Ohio). Students will continue research during the following academic year.
When: July 10-August 7
Where: The Westfjords region of northwestern Iceland, and The College of Wooster (Wooster, Ohio)
Who: Six students
Project faculty: Brennan Jordan (University of South Dakota) and Meagen Pollock (The College of Wooster)
Project Overview and Goals
The 103,000 km3 island of Iceland has been produced by geologically continuous volcanism over the last 15 million years. The robust volcanism of Iceland is the result of the intersection of the Mid-Atlantic Ridge with a hotspot, generally interpreted as a mantle plume. The focus of rifting within Iceland has shifted several times during its history. A widely accepted model for the tectonic evolution of Iceland is: the mid-ocean ridge system drifts to the west relative to the hotspot, and Icelandic rifts are abandoned as they drift off of the hotspot in favor of new rifts centered on the hotspot.
Unusual in an oceanic environment, Iceland produces a spectrum of volcanic products from basalt to rhyolite, with rhyolites erupted only at central volcanoes. The crustal magmatic processes responsible for this spectrum of compositions includes mantle melting, crustal melting, fractional crystallization, assimilation, and recharge. The overarching question this research project seeks to address is: do magmatic processes vary systematically as a rift evolves from its inception to its abandonment?
The 2011 Iceland Keck project is the fourth in a cycle of projects investigating a series of central volcanoes erupted from the Skagi-Snaefellsnes rift zone which was active between 15 and 7 Ma. The Hrafnfjordur central volcano is the oldest of the centers investigated in this cycle, representing the early, hotspot-centered, portion of the evolution of the rift zone. Our goal is to investigate the processes of formation and evolution of magmas in the Hrafnjordur central volcano and determine the relative importance of different magmatic processes. Our data and interpretations can then be considered in the context of results from the previous projects to evaluate systematic changes during the evolution of the rift.
Potential Student Projects
The field project will involve reconnaissance mapping, sampling, and characterization of the physical volcanology of units in the study area. All students will likely be involved in all aspects of fieldwork. Most follow-up laboratory studies will include bulk rock geochemistry (XRF and ICP-MS) and thin section analysis. Some may utilize additional techniques, as available at home institutions. A range of individual student projects will be available including:
- Petrology and physical volcanology of rhyolite, and possibly intermediate, lavas at Hrafnfjordur (several projects)
- Petrology of basaltic units at Hrafnfjordur (potentially several projects)
- Petrology of units encountered in reconnaissance of sequence above Sudavik
- Physical volcanology of pyroclastic units
- Mineral chemistry of volcanic units
- Structural geology of Hrafnfjordur central volcano
- Dikes: petrology and structure
Field Conditions & Logistics
The project will open with a field trip through the younger volcanic regions of Iceland to provide a modern analog for the older rocks we will see in the study area. The field portion of this project will be conducted in a rugged and remote area in northwestern Iceland. We will reach this area by boat from Isafjordur. The bulk of fieldwork will involve hiking off-trail in steep rocky terrain, and most days will involve hiking several kilometers with over 300 m (1,000 feet) of elevation gain. Students should be comfortable in this kind of terrain and should be in good physical condition. Iceland has a cool wet climate, and students will need to be prepared to work in rain and wind at about 10 °C (50 °F).
Students will need to either own or borrow camping gear for the field portion of the project. A period of ten days will be spent “primitive camping” with no facilities. This can be rewarding but is also challenging, and students should realistically consider whether they are up to this challenge before applying.
Due to the expense of conducting a project in Iceland, some students may need to contribute some of their stipend (or other resources) toward their travel expenses. The itinerary for travel to Iceland and Ohio is expected to cost $1,100-$1,600 (depending on departure city) of which only the first $1,100 will be paid by the project.
Courses in mineralogy and petrology are prerequisites for this project with the caveat that one position may be allocated to a student who has had structural geology but not mineralogy and petrology. Stratigraphy and field methods are recommended but not required.