Published Papers
| Jefferson, AJ, Kearns, K, Snyder, K, Mitchell, A, Muratori, S, and Rowan, CJ (2025). Anthropogenic litter and plastics across size classes on a mechanically groomed Great Lakes urban beach. |
|---|
| Journal of Great Lakes Research, 51(2), 102505. |
| doi: 10.1016/j.jglr.2024.102505 |
| Repeat sampling of a Cleveland beach over a single summer demonstrated that although mechanical grooming and other maintenance methods could reduce the surface concentrations of plastics and other litter at this beach, it did little to effect the overall abundance in the upper 5cm of beach sediment, which was among the highest yet measured in the Great Lakes. This was largely because most plastics were too small to be removed by grooming. |
| Rowan, CJ and Mulvey, BK (2023). An innovative cycle-based learning approach to teaching with analog sandbox models. |
|---|
| Journal of Geoscience Education, 71(1), p74-86 |
| doi: 10.1080/10899995.2022.2097566 |
| Cycle-based learning allows students to evaluate and revise their predictions in the light of their observations. We designed a cycle-based learning activity for use with sandbox modeling and tested it in an upper-level tectonics class. Following multiple rounds of convergence and experiments with different experimental set-ups, students showed marked improvement in the quality of their predictions and their penetrative thinking skill, as measured by pre- and post-activity spatial visualization tests. Read more here. |
| Roberts, AP, Zhao, X, Harrison, RJ, Heslop, D, Muxworthy, AR, Rowan, CJ, Larrasoaña, JC, and Florindo, F (2018). Signatures of Reductive Magnetic Mineral Diagenesis From Unmixing of First-Order Reversal Curves. |
|---|
| Journal of Geophysical Research, Solid Earth, 123(6), B015706 |
| doi: 10.1029/2018JB015706 |
| We apply a newly developed analytical method to analyze magnetic mineral assemblages during various stages of reductive magnetic mineral diagenesis in marine sediments. Read more here. |
| Rowan, CJ, and Rowley, DB (2017). Preserved History of Global Mean Spreading Rate: 83 Ma to Present. |
|---|
| Geophysical Journal International, 208, p1173-1183. |
| doi: 10.1093/gji/ggw277 |
| The ocean floor records the production of oceanic lithosphere as far back as the Jurassic, but due to subduction, this record is not complete. This study characterizes the directly reconstructable spreading history preserved in the modern ocean basins, and estimates the uncertainties in global mean spreading rates that result from this partial record. We show that the Late Cretaceous global mean spreading rate has estimated uncertainties of ±20%, allowing both relatively unchanged global mean spreading rates and accelerated rates hypothesized in many studies, which are almost entirely based on extrapolated reconstructions of ridges that have no preserved record. |
| Rowley, DB, Forte, AM, Rowan, CJ, Moucha, R, Grand, SP, and Simmons, NA (2016). Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling. |
|---|
| Science Advances, 2(12), e160107 |
| doi: 10.1126/sciadv.1601107 |
| The asthenosphere beneath most mid-ocean ridges passively upwells in response to plate separation. This study combines reconstructions of surface plate motions with mantle convection modeling to argue that some unusual characteristics of the East Pacific Rise – its pronounced spreading asymmetry and its very limited motion across the mantle in the past 83 Ma – are linked to a long lived upwelling from the core-mantle boundary that is positioned beneath the ridge axis in the SE Pacific. In this location, the asthenosphere may be acting on the plates, rather than just responding to their motion. |
| Rowan, CJ and Rowley, DB (2014). Spreading behaviour of the Pacific-Farallon ridge system since 83 Ma. |
|---|
| Geophysical Journal International, 197, p1273-1283. |
| doi: 10.1093/gji/ggu056 |
| We use digitised magnetic anomaly and fracture zone picks from the North and Central Pacific to produce improved spreading parameters for the East Pacific Rise and its longer ancestor, the Pacific-Farallon ridge, since chron 34y (83 Ma). We also identify quasi-periodic 15-20 Myr variations in spreading rate and spreading asymmetry for at least the past 50 Myr. Read more here. |
Roberts, AP, Chang, L, Rowan, CJ, Horng, CS and Florindo, F (2011). Magnetic properties of sedimentary greigite (Fe3S4): An update
Reviews of Geophysics 49(1), RG1002
doi: 10.1029/2010RG000336
Chang, L, Roberts, AP, Rowan, CJ, Tang, Y, Pruner, P, Chen, Q and Horng, CS (2009). Low-temperature magnetic properties of greigite (Fe3S4)
Geochemistry, Geophysics, Geosystems 10(1), Q01Y04
doi: 10.1029/2008GC002276
| Rowan CJ, Roberts, AP and Broadbent, T (2009). Reductive diagenesis, magnetite dissolution, greigite growth and paleomagnetic smoothing in marine sediments: A new view. |
|---|
| Earth and Planetary Science Letters, 277, p223-235. |
| doi: 10.1016/j.epsl.2008.10.016 | Download PDF |
| Detailed rock magnetic measurements and electron microscopy are used to chart the dissolution of magnetite and its slow replacement by greigite as the principal magnetic mineral in rapidly deposited marine sediment cores collected off the coasts of Oman and Northern California. The key observation is that growth of greigite occurs over prolonged timescales (10s to 100s of thousands of years), which will lead to smoothing of any paleomagnetic signal that is recorded in these sequences. We show that published rock magnetic data from many other cores around the world also show similar trends, suggesting that this problem might be widespread. |
Rowan, CJ and Roberts, AP (2008). Widespread remagnetizations and a new view of Neogene tectonic rotations within the Australia-Pacific plate boundary zone, New Zealand.
Journal of Geophysical Research 113, B03103.
doi: 10.1029/2006JB004594 | Download PDF
Chang, L, Roberts, AP, Muxworthy, AR, Tang Y, Chen, Rowan, CJ, Liu, Q and Pruner P (2007). Magnetic characteristics of synthetic pseudo-single-domain and multi- domain greigite (Fe3S4)
Geophysical Research Letters 34(24), L24304
doi: 10.1029/2007GL032114
Roberts, AP, Bakrania, A, Florindo, F, Rowan, CJ, Fielding, CR and Powell, RD (2007). High-resolution evidence for dynamic transitional geomagnetic field behaviour from a Miocene reversal, McMurdo Sound, Ross Sea, Antarctica
Earth Planets Space Vol. 59(7), p 815-824.
Abstract
Roberts, AP, Liu, Q, Rowan, CJ, Chang, L, Carvallo, C, Torrent, J and Horng, CS (2006). Characterization of hematite (α-Fe2O3), goethite (α-FeOOH), greigite (Fe3S4), and pyrrhotite (Fe7S8) using first-order reversal curve diagrams
Journal of Geophysical Research 111(B12), B12S35
doi: 10.1029/2006JB004715
Rowan, CJ and Roberts, AP (2006). Magnetite dissolution, diachronous greigite formation, and secondary magnetizations from pyrite oxidation: Unravelling complex magnetizations in Neogene marine sediments from New Zealand.
Earth and Planetary Science Letters 241(1-2), p119-137.
doi: 10.1016/j.epsl.2005.10.017 | Download PDF
Rowan, CJ and Roberts, AP (2005). Tectonic and geochronological implications of variably timed magnetizations carried by authigenic greigite in marine sediments from New Zealand.
Geology 33(7), p553-556.
doi: 10.1130/G21382.1 | Download PDF
Rowan, CJ, Roberts, AP and Rait, GJ (2005). Relocation of the tectonic boundary between the Raukumara and Wairoa Domains (East Coast, North Island, New Zealand): implications for the rotation history of the Hikurangi margin.
New Zealand Journal of Geology and Geophysics 48(1), p185-196.
Abstract | Download PDF