How to distinguish the roles of transport and source changes in sedimentary records (New paper in G-Cubed!).

Understanding how changes in sediment transport and changes in sediment provenance influence sedimentary and magnetic records is a fundamental, but challenging problem in the study of sediment cores. The OSU P-mag lab has a new paper out in G-cubed led by Rob Hatfield and former undergraduate researcher, Ben Wheeler, that investigates this in the Northern North Atlantic.  Our new study uses a network of 71 core top samples from the Norwegian and Greenland Seas, originally collected in 1963 and currently archived at the OSU Marine and Geology Repository. Sediments were seperated into 5 particle size fractions and the magnetic properties of the bulk sediments and the particle size fractions were measured at the Pacific Northwest Paleomagnetic Laboratory at Western Washington University. The “Edisto Array” used in the newly published Hatfield et al. G-cubed paper.  Cores were recovered in 1963 and archived at the OSU Marine and Geology Repository since that time. There is a long history of studying the magnetic properties of Northern North Atlantic (NNA) sediments as sensitive indicators of changes to Earth Systems.  For example, back in 1995 Joe Stoner and colleagues published a paper in Geology documenting major differences in the magnetic properties of Eirik Ridge sediments (south of Greenland) during the last two glacial terminations.  These differences were interpreted to reflect differences in the timing and style of Greenland deglaciation during these times.  To better understand these changes and investigate how these signals may be influenced by changes in sediment source and/or transport, Rob Hatfield collected potential source sediments from glacial streams around Greenland and Iceland and investigated their particle-size specific magnetic properties (see papers published in 2013...

The P-mag Lab on the Move (Literally)

In December, there was a fire in Burt Hall.  Thankfully, the P-mag Lab survived with very minimal damage, but the building around us needs a lot of work.  So today, Joe, Brendan and our friends Dave and Chris from 2-G Enterprises took apart the magnetometer and moved it to the new Marine and Geology Repository being built at Oregon State.  Everything went well and we are looking forward to being up and running again in a few months.  Check out some pictures of the move below.   The OSU P-mag Lab with our u-channel magnetometer before the fire/move. Taking apart the magnetometer. Joe and Dave discussing how to move the almost 400 lb impulse magnetizer we use to impart Isothermal Remanent Magnetizations (IRMs). Must be someone’s birthday!. I hope its an amplifier! Joe, Dave, and Chris loading the magnetometer into the moving truck. Joe showing off his new mobile P-mag Lab. Taking a break to check out the progress of organizing many kilometers of sediment cores at the new OSU Marine and Geology Repository Val loading cores into the racks. Jason moving the impulse magnetizer into the Marine and Geology Repository. Joe, Dave, and Chris unloading the magnetometer from the truck. Joe making sure the magnetometer is safe. A rare look at the in-line alternating field coils we use to demagnetize our samples. The OSU P-mag Lab Magnetometer’s temporary home. Joe and Dave planning the P-mag Lab’s future. Dave thinking if this room could be the new OSU P-mag Lab...

The P-mag Lab at the 2018 AGU Fall Meeting

The OSU P-mag Lab is headed to Washington D.C. next week for the 2018 AGU Fall Meeting. If you are there, learn about some of the research we are working on, including projects from the Bay of Bengal, Peru, Northern North Atlantic, Western North America, Nares Strait, and the High Arctic.   Tuesday Michael Weber & Brendan Reilly (Oral Presentation) PP23C-03: Bengal Fan depositional history through Pleistocene climate, monsoon, and sea level transitions (Link to QSR Paper) Tuesday, 11 December 2018 14:10 – 14:25 Walter E Washington Convention Center – Salon I   Wednesday Robert Hatfield et al. (Oral Presentation) GP34A-04: Assessing Orbital Forcing in the Tropical Andes: Developing a 700 kyr paleointensity assisted chronology for ICDP drilling in Lake Junín, Peru Wednesday, 12 December 2018 16:45 – 17:00 Marriott Marquis – Independence D   Thursday Benjamin Freiberg et al. (Oral Presentation) GP41A-06: The Particle Size Specific Magnetic Properties of Eirik Ridge Sediments over the Last 150 ka from IODP Expedition 303 U1305 and U1306: Disentangling the Influences of the Greenland Ice Sheet and Deep Western Boundary Current Thursday, 13 December 2018 09:15 – 09:30 Marriott Marquis – Independence D   Joseph Stoner et al. (Poster Presentation) GP43B-0781: Regionally Consistent Western North America Paleomagnetic Directions from 15-35 ka: Assessing Chronology and Uncertainty with Paleosecular Variation (PSV) Stratigraphy (Link to QSR Paper) Thursday, 13 December 2018 13:40 – 18:00 Walter E Washington Convention Center – Hall A-C (Poster Hall)   Anne Jennings et al. (Oral Presentation) PP41B-02: Sediment and Faunal Evidence of Ice Shelves and Their Disintegration during the Early Holocene Deglaciation of Nares Strait Thursday, 13 December 2018 08:15 – 08:30 Walter E Washington...

Late Pleistocene Western North American PSV Paper Now Online at QSR!

The OSU P-mag Lab’s study on Late Pleistocene Western North American Paleomagnetic Secular Variation (PSV) is now available online at Quaternary Science Reviews.  It is titled, “Regionally consistent Western North America paleomagnetic directions from 15 to 35 ka: Assessing chronology and uncertainty with paleosecular variation (PSV) stratigraphy” and is the result of work that began with sediment cores collected in 2014 from Fish Lake, Utah.  You can access the paper for free until December 12, 2018 using the following share link: https://authors.elsevier.com/a/1XxYs-4PRq9MZ.  If you need a copy after that, just email Brendan, Joe, or Rob and we can send you a version.   In February 2014, Joe and Rob traveled to Utah to collect sediment cores from the frozen surface of Fish Lake, the largest natural mountain lake in the state, with colleagues from the University of Pittsburgh, Western State Colorado University, University of Utah, the USGS, University of West Virginia, College of Charleston, and the Illinois State Museum.  Fish Lake is situated in a northeast-southwest trending graben in the high plateau of Utah, a transitional region between the Colorado Plateau and the Basin and Range. During the last glacial time interval, glaciers drained from the nearby Fish Lake High-top Plateau into the Fish Lake Basin without overrunning the lake. Thus, sediments in the lake contain a record of times before, during, and after the last glacial maximum.   The Fish Lake coring team in February 2014 using a UWITEC coring device from the frozen surface of the lake.   Joe and Rob returned to Oregon State with 12 ~2 meter long cores from the lake, which could be used...

Off to Copenhagen to support IODP Proposal: Assessing the history of the south Greenland Ice Sheet and its interaction with ocean circulation, climate, and sea level

Joe, Rob, and Brendan are off to Copenhagen in support of their IODP proposal, 814-Full: Assessing the history of the south Greenland Ice Sheet and its interaction with ocean circulation, climate, and sea level.  This drilling proposal was the result of a 2012 IODP, NSF, and PAGES workshop, Assessing the History of the Greenland Ice Sheet through Ocean Drilling (link to workshop report).  They will be attending the IODP and ECORD MagellanPlus Workshop on Greenland Ice Sheet evolution, organized by Paul Knutz at GEUS. The participants will discuss 814-Full and another IODP Proposal, 909-Full: Cenozoic evolution of the northern Greenland ice sheet (NORTH ICE).  It looks like it will be an incredible workshop, with three days of Greenland focused talks, discussions, and planning sessions.   P-mag Lab presentations at the meeting: Joe will be presenting the summary and status of the IODP 814-Full proposal and a keynote talk, titled: “Linking the marine sediment archive to Greenland Ice Sheet variability: Past and (hopefully) future ocean drilling around South Greenland.” Rob will be presenting a talk to highlight the work our group has done around South Greenland and the Northern North Atlantic, titled: “Eirik Ridge marine sediments: A Plio-Pleistocene archive of the past behavior of the south Greenland Ice-Sheet.” Brendan will be presenting a poster to encourage discussion on chronostratigraphic modeling, titled: “Chronostratigraphic modeling of complex depositional systems: Lessons from the Bengal Fan, implications for ice proximal environments.” And close collaborator Anne Jennings, at INSTAAR at CU-Boulder, will be presenting a talk on results from our 2015 Petermann Glacier Expedition, titled: “Ice Shelf Facies: Modern and Paleo examples from NW...

The P-mag Lab Continues Strong Partnership with IODP During the 2018/19 Academic Year

The P-mag Lab will continue to have a strong partnership with IODP in the 2018/19 academic year and is committed to developing, implementing, and achieving IODP scientific objectives. We are starting the year by participating in two IODP workshops focused on planning future drilling around the Greenland Ice Sheet and in the Arctic/North Pacific.  The first of these will be in support of IODP Proposal 814-Full, led by Joe, which plans to target sites on the South Greenland Margin that will extend back to the late-Miocene.  The latter will help develop drilling targets identified during our recent work on the Oregon Margin on cruises OC1706B (Co-Chiefs, Mo/Joe) and RR1718 (Mo/Brendan). In December, Rob will head out on the JOIDES Resolution (JR) to serve as Paleomagnetist on the first JR100 cruise, which utilizes the drilling capabilities of the JR to drill shallow (<100 m) sites while the JR is in transit and/or in between IODP Expeditions.  They will be drilling a number of sites on the Chilean Margin to recover high-resolution records of the region’s past climate and oceanographic conditions. In March, Brendan will get on the JR to serve as Paleomagnetist on IODP Expedition 382, which will drill basins in the Scotia Sea and a drift on the South Falkland Slope to learn about past Antarctic Ice Sheet discharge, through the Iceberg Alley ice-rafted debris record, and Southern Ocean paleoceanography since the Middle Miocene. Finally, in May, Joe will shake hands with Brendan getting off the JR and then get on himself to serve as Paleomagnetist on IODP Expedition 383, which will investigate the Pliocene-Pleistocene dynamics of the Pacific Antarctic Circumpolar...