Larryn W. Diamond's research while affiliated with Universität Bern and other places

Publications (6)

Article
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Pervasive alteration of basaltic oceanic crust by heated seawater at greenschist facies conditions produces two contrasting hydrothermal rocks. “Spilites”, consisting of chlorite + albite + quartz ± actinolite ± epidote, occur typically with regional extents. Locally spilites are metasomatically transformed to “epidosites” consisting of epidote + q...
Article
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Hydrostatic pressure exerted by the ocean water column fundamentally influences magmatic and hydrothermal processes in submarine volcanic settings and is therefore an important parameter to know when investigating such processes. Currently, there are few reliable methods for reconstructing past ocean depths for ancient volcanic terranes. Here, we d...
Article
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Hydrothermal circulation through oceanic crust, and all the transfers of mass and heat caused by this circulation, are controlled by the evolving permeability of the altered basaltic rocks at in-situ pressures (P) and temperatures (T). Numerical models designed to elucidate these processes therefore rely on knowledge of the rock-matrix permeabiliti...
Article
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Epidosites are a prominent type of subseafloor hydrothermal alteration of basalts in ophiolites and greenstone belts, showing an end‐member mineral assemblage of epidote + quartz + titanite + Fe‐oxide. Epidosites are known to form within crustal‐scale upflow zones and their fluids have been proposed as deep equivalents of black‐smoker seafloor vent...
Article
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p>Numerous studies have revealed genetic similarities between Tethyan ophiolites and oceanic “proto-arc” sequences formed above nascent subduction zones. The Semail ophiolite (Oman–U.A.E.) in particular can be viewed as an analogue for this proto-arc crust. Though proto-arc magmatism and the mechanisms of subduction initiation are of great interest...

Citations

... This igneous suite encompasses meta-basaltic massive, porphyritic volcanic rocks and coarse-to-medium-grained specimens originating from dikes (dolerite, proterobase). Where hydrothermal alteration, such as splitisation or argillitization, was too intensive so as to enable us any precise identification of the rock-forming minerals and a determination of the parent material, the general term metavolcanic rocks is used for classification [83]. Serpentinites and epidote amphibolites (greenstones) belong to the Ordovician Greenschist Zone (Table 1, Figure 2). ...
... The isochores in Fig. 11 can be used to estimate the pressure of fluid trapping (P trap ) by first estimating the depth of trapping below sealevel (i.e., the sum of seawater depth plus paleostratigraphic depth below seafloor) and then adopting a relationship between depth and fluid pressure. We have used the synvolcanic ocean depth of 3.1-3.5 km (corresponding to pressures of 31-35 MPa) defined by the overlap between sedimentary CCD evidence and volatile contents in glass in the paleobathymetric study of the Semail ophiolite by Belgrano et al. (2021). The paleostratigraphic depth of each sample was converted to hydrostatic pressure taking into account the density of the fluid at trapping, as defined by the relevant isochores. ...
... Alteration to endmember epidosite produces granoblastic rocks consisting of epidote + quartz + minor titanite and Fe-oxides (Gilgen et al., 2016;Weber et al., 2021). At the outcrop scale, epidotisation develops differently through the different upper-crustal lithologies. ...
... Heinrich, F. C., V. Schmidt, M. Schramm, and M. Mertineit (2019), Anisotropy of magnetic susceptibility in salt rocks from the German Zechstein Basin, Sondershausen mine, Geophysical Journal International, 219(1), 690-712. Hirt, A. M., and A. R. Biedermann (2019), Preferred orientation of ferromagnetic phases in rock-forming minerals: insights from magnetic anisotropy of single crystals, Canadian Journal of Earth Sciences, 56(9), 994-1001. Kuehn, R., A. M. Hirt, A. R. Biedermann, and B. Leiss (2019), Quantitative comparison of microfabric and magnetic fabric in black shales from the Appalachian plateau (western Pennsylvania, USA), Tectonophysics, 765, 161-171. ...