Paleoseismicity Research: From Trench to Earthquake Hazard Map

/
Paleoseismicity Research: From Trench to Earthquake Hazard Map

Dr. Ashley Streig, Assistant Professor in the Geology Department of Portland State University and NSF Postdoctoral Research Fellow, gave a talk to GSOC about her paleoseismology research on the San Andreas Fault in California. Streig’s research in the Hazel Dell site in the Santa Cruz Mountains was interpreted as showing the results of 3 significant earthquakes happening since the land was settled and logged by the first Spanish settlers.

Read More

Cookie Dough, Jelly Sandwiches, and Structural Geology: A Beginner’s Guide

/
Cookie Dough, Jelly Sandwiches, and Structural Geology: A Beginner’s Guide

Dr. Nancy Price, a recent addition to the faculty at Portland State University and a structural geology specialist, spoke to GSOC about her research in rheology. As she described her work in the course of the lecture, Price looks at metamorphic rock outcrops and samples in order to determine the histories of events which have been recorded in their structure.

Read More

Meteorite Findings and “Greatest Hits”

/
Meteorite Findings and “Greatest Hits”

Pictured: polished and etched silicate-bearing iron meteorite, with millimeter scale at left

Meteorites “Greatest Hits” from Dr. Ruzicka's May 8th lecture: (1) The solar system formed relatively fast, in only 10 million years; (2) Much early planetary material was either partly melted, evaporated, and/or dispersed in the early solar nebula; (3) Pre-solar grains are incorporated in the chondrite matrix; (4) Pre-biotic organic synthesis occurred as building blocks in the early solar system; (5) Decay of short-lived radioactive isotopes gave the heat source of silica-rich bodies in the early solar system; (6) Planetary rock swaps occurred throughout the history of the solar system. 

Read More

Synopsis of Dr. John Bershaw's GSOC Friday Night Lecture, April 10, 2015

/
Synopsis of Dr. John Bershaw's GSOC Friday Night Lecture, April 10, 2015

Using Fossil Teeth and Paleoclimatology to Bracket Duration of Andean Uplift 

Dr. John Bershaw, PSU Department of Geology, came to the GSOC Friday night lecture in April to discuss his research using fossils to determine information about past climate change. Specifically, Bershaw’s task was to use oxygen isotopes in fossil mammal teeth to bracket the age of formation of the Andean Plateau (Altiplano) in South America. 

Read More

Mt. Lassen – a Geological Must-See

/
Mt. Lassen – a Geological Must-See

About 100 of us gathered in Cramer Hall 53 to hear the very knowledgeable geologist Dr. Scott Burns talk about his newest adventure – first trip to Mt. Lassen National Park. This active volcano, the southernmost in the Cascade Mountains, last erupted in 1916. The mode of eruptions seems to be bi-modal – either quiet or violent. The volcano was named after Danish immigrant Peter Lassen who was a local blacksmith. The LA Times recently wrote that Mt. Lassen was California’s “most overlooked volcanic park” with only 400,000 visitors per year, as compared with Yosemite’s 4-million visitors per year.

Read More

Rhyolites, CRBs & the Yellowstone Hot Spot — Research by Dr. Martin Streck

/
Rhyolites, CRBs & the Yellowstone Hot Spot — Research by Dr. Martin Streck

Martin Streck spoke to a standing room only GSOC crowd about the work that he and a number of his graduate students have done in advancing our knowledge of the Columbia River Basalt (CRB) flows of the Miocene. His team has focused upon the rhyolite flows that occurred as a result of heating by the basalt magma that produced the CRB.

Miocene rhyolite flows in eastern Oregon have long been studied by geologists. The relationship between the rhyolitic magma and the massive amounts of CRB basaltic magma is not precisely known, although they are spatially close so infer that the rhyolite is a result either of partial melting of the crust by or fractional crystallization of the CRB magma. In fact, the spatial distribution over time of the rhyolite can give geologists ideas about the origin of the CRB magma itself.

Read More

Radon in the Willamette Valley: An Unexpected Hazard

/
Radon in the Willamette Valley: An Unexpected Hazard

At the end of the last ice age 18,000 to 15,000 years ago massive hydrologic floods ran down the Columbia River Gorge.  Originating from a huge glacial lake near Missoula, Montanta around forty floods were large enough to flood the entire Willamette Valley to a depth of 400 ft.  These floods did not just bring huge volumes of water, they brought huge amounts of rocks and sediments from the continental batholiths.  A large percentage of these rocks and sediments are composed of granite.  Granites from the Idaho batholith are high in uranium bearing minerals.  This high uranium content brings with it an unexpected hazard, radon.

Read More

Slide Identification and Evaluation in Norway

/
Slide Identification and Evaluation in Norway

Dr. Adam Booth, Portland State University Department of Geology, spoke to GSOC on October 10 about his research with the Norwegian Geological Survey (NGU). Norway is a country with a landslide problem on its western shore. There some of the world's highest escarpments of gneiss and schist tower over steeply carved glacial fjords. Towns and villages huddle at the bottom of these steep slopes on flat land created by the rock falls and debris flows which come from the slopes above. Blocks of material catastrophically fail periodically along steep foliation planes, sending material plummeting into the fjord below and creating immense waves. Three such events occurred in the twentieth century, leaving a wake of destruction and taking nearly 200 lives.

Read More

LUSI Mud Eruption: Natural or Man-Made Disaster?

/
LUSI Mud Eruption: Natural or Man-Made Disaster?

Ever since the mud started spewing from the Lumpur Sidoarjo (aka “Lusi”) mud volcano in the subdistrict of Porong, Sidoarjo on East Java Island, Indonesia, on May 29, 2006, an opportunity to study the feature and, fortunately or unfortunately, become embroiled in the political controversy over it opened in the geological community. Newly appointed Assistant Professor Maxwell Rudolph of Portland State University was involved in studies related to this phenomenon during his doctoral years at UC Berkeley ending in 2012, and spoke to GSOC at the June Friday night lecture describing his work. 

Read More