China on Russia’s intervention in Syria. OSW Commentary Number 193|19.01.2016

China has reacted positively to Russia’s military intervention in Syria. The Chinese government perceives it as an element of the global fight against terrorism, and has emphasised the fact that Russia was acting in response to a request by the Syrian government. At the same time, Beijing has argued that the Syrian conflict cannot be resolved by military means and that a political compromise is necessary.

(Table T1) Physical properties of minicores from ODP Leg 193 sites, PACMANUS field

Permeability of the ocean crust is one of the most crucial parameters for constraining submarine fluid flow systems. Active hydrothermal fields are dynamic areas where fluid flow strongly affects the geochemistry and biology of the surrounding environment. There have been few permeability measurements in these regions, especially in felsic-hosted hydrothermal systems. We present a data set of 38 permeability and porosity measurements from the PACMANUS hydrothermal field, an actively venting, felsic hydrothermal field in the eastern Manus Basin. Permeability was measured using a complex transient method on 2.54-cm minicores. Permeability varies greatly between the samples, spanning over five orders of magnitude. Permeability decreases with both depth and decreasing porosity. When the alteration intensity of individual samples is considered, relationships between depth and porosity and permeability become more clearly defined. For incompletely altered samples (defined as >5% fresh rock), permeability and porosity are constant with depth. For completely altered samples (defined as <5% fresh rock), permeability and porosity decrease with depth. On average, the permeability values from the PACMANUS hydrothermal field are greater than those in other submarine environments using similar core-scale laboratory measurements; the average permeability, 4.5 x 10-16 m**2, is two to four orders of magnitude greater than in other areas. Although the core-scale permeability is higher than in other seafloor environments, it is still too low to obtain the fluid velocities observed in the PACMANUS hydrothermal field based on simplified analytical calculations. It is likely that core-scale permeability measurements are not representative of bulk rock permeability of the hydrothermal system overall, and that the latter is predominantly fracture controlled.

(Table T1) Bulk rock geochemistry of fresh lavas from ODP Leg 193 sites, PACMANUS field

Leg 193 was the fourth Ocean Drilling Program expedition focusing on understanding subseafloor hydrothermal systems. This program was the first to combine studies of the volcanology, structure, hydrology, mineralization, and microbiology of a subseafloor hydrothermal system hosted by felsic rocks by coring at the PACMANUS hydrothermal field in the Manus Basin, Papua New Guinea. The study examines only the petrology and bulk rock and mineral chemistry of the freshest and most morphologically youthful lava flows recovered from the shallowest drill cores at the four sites occupied during Leg 193. There are subtle but distinct petrographic and geochemical variations between the closely spaced sites.