Monday, 21 April 2014

flint / chalk /



Each event, however commonplace and insignificant, thus became the speck of impurity around which experience accrued its authority, like a pearl.

Agamben / Infancy & History / 14


The majority of silica found in flint nodules is biogenic (produced by living organisms or biological processes). Although today's flint nodules are inorganic, the silica that formed them was originally sourced from the remains of sea sponges and siliceous planktonic micro-organisms (diatoms, radiolarians) during the late cretaceous period (60-95 million years ago). Flints are concretions that grew within the sediment after its deposition by the precipitation of silica; filling burrows/cavities and enveloping the remains of marine creatures, before dehydrating and hardening into the microscopic quartz crystals which constitute flint.

 

 The exact mode of formation of flint is not yet clear but it is thought that it occurs as a result of chemical changes in compressed sedimentary rock formations, during the process of diagenesis. One hypothesis is that a gelatinous material fills cavities in the sediment, such as holes bored by crustaceans or molluscs and that this becomes silicified. This theory certainly explains the complex shapes of flint nodules that are found. The source of dissolved silica in the porous media could arise from the spicules of silicious sponges.[3] Certain types of flint, such as that from the south coast of England, contains trapped fossilised marine flora. Pieces of coral and vegetation have been found preserved like amber inside the flint. Thin slices of the stone often reveal this effect.

 

How flint is formed


The formation of flint is a complex process which began in the chalk seas millions of years ago and is, summarised below:

Organisms such as sponges (on the macro scale) and radiolaria/diatoms (on the micro scale) use silica from sea water to manufacture the biogenic opal which forms their skeletons. When the organisms die and the organic parts decay the microscopic silica is scattered on the sea bed and becomes incorporated in the accumulating sediment.

At depths of 1 to 5m within this sediment, the biogenic opal breaks down, enriching the water between the sediment particles (sediment pore water) with silica.

At sediment depths of less than 10m, there is an oxic-anoxic boundary where hydrogen sulphide rising from the decomposing organic material within the sediment diffuses upwards meets oxygen diffusing downwards from the water column above. At this interface, the hydrogen sulphide is oxidised to sulphate with hydrogen ions as a by-product. The hydrogen ions lower the local pH, dissolving the chalk and thereby increasing the concentration of carbonate ions. These act as a seeding agent for the precipitation of silica.

Silica precipitates by the molecule-by-molecule replacement of chalk. The silica is initially in the form of crystalline opal but gradually transforms to quartz (flint) during later burial and with time.

The chalk sea bed is deeply burrowed by many different organisms, such as shells, echinoids and worms etc. Some of these burrows are quite deep or branching, or have open living spaces. The burrows fill with sediment after the organism has died, this is slightly different material from the sediment around it. These filled burrows act as preferential pathways (conduits) for the chemical reactions to occur. Flint formed within these old burrows often has a nodular shape which reflects the whole, or part of, overgrown remnants of such burrow systems.

There are two possible explanations for why flint forms in bands or layers. Firstly because chalk sedimentation occurs in cycles and secondly because the process above exhausts the silica within a given depth of sediment and flint formation can only recommence when there is enough silica to start the process again.

 

Sunday, 20 April 2014

Gell / Agents/ Patients

It is important to understand though, that 'patients' in agent/patient interactions are not entirely passive; they may resist. The concept of agency implies the overcoming of resistance, difficulty, inertia, etc. Art objects are characteristically 'difficult'. They are difficult to make, difficlut to 'think', difficut to transact. They fascinate, compel, and entrap as well as delight the specataor. Their peculiraity, intransigence and oddness is a key factor in their efficacy as social instruments. Moreover, in the vicinity of art objects, struggles for control are played out in which 'patients' intervene in the enchainment of intention, instrument and result as 'passive agents', that is, intermediaries between ultimate agents and ultimate patients. Agent/patient relations from nested heirarchies whose characteristics will be described in due course. The concept of the 'patient' is not, therefore a simple one, in that being a 'patient' may be a form of (derivative) agency.

Gell / Art & Agency / 24



http://www.academia.edu/186556/The_Awareness_of_Rock_East-Asian_Understandings_and_Implications_2009_

Graham Parkes

look out






Thursday, 17 April 2014

Wednesday, 9 April 2014

vulva | vultus

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Apotropaic patterns [Gell] are demon –traps, in effect, demonic fly-paper.
Pattern and multiplicity operate like this
Bringing about attachment between people and objects



 

 
in short there is a choice between vulva and vultus, genitals and face, two fantastical equivalents... 




 patrimony - dad's 'diamond' in blue, wedgwood - design 63 - apothecary jar

cellini perseus




Tuesday, 8 April 2014

the origin of coral




Before washing his hands, Perseus delicately sets the serpent-crowned head onto a bed of leaves so that it won't be injured. But, on contact, the supple seaweed stems absorb the monsters power and harden. Henceforth coral - called gorgonion in Greek- possesses the property of becoming mineral if exposed to air. In water, its branches are flexible, but as soon as it emerges it turns to stone, saxum. In Ovid it is the Gorgon's contagious touch that petrifies, but in other versions it is her gaze.

Kristeva/ The Severed Head p29



The origin of this scene is a seldom-illustrated passage from Book IV of Ovid's Metamorphoses, describing how Perseus created coral. Having slain the Medusa, one of the three Gorgons, whose gaze turned all who saw her to stone, Perseus witnessed the birth of the winged white horse Pegasus, who sprang from her blood. Mounted on Pegasus with the Medusa's head in a sack, Perseus flew over an island where he saw Andromeda chained to a cliff and threatened by a sea-monster. Perseus slew the monster, freed Andromeda and began washing the creature's blood from his hands, placing the Medusa's head on some seaweed at the water's edge as he did so. The Medusa's blood turned the seaweed into a red stone - coral. Delighted with the effect, the nymphs soaked other algae in the blood, to make more.

Sunday, 6 April 2014

scanning the folkton drums




"Work' rather than 'labour', our ancestors' archaic occupation, which produced these objects, had concealing them from human eyes as its extravagant goal. The paradox appears to us alone. Turned towards the dead, intended for the dead, these creations were meant to be restored to them: sent back to the invisible, they were in this sense, literally, 'sacrificed'. But, in actualising that sacrifice, they were permeated with the power to which one sacrificed, the power of life and death. And even when it was displayed, the sacred work was not meant to be sampled by the eyes of the living, as is now accepted in our modern museumized culture. When they found their way into the world of the visible, these man-made artefacts continued to intercede with the invisible powers, to transpose their virtues to the living. That was their sacred logic.

Kristeva / The Severed Head/ Capital Visions / pp9-10