Cation ordering of orthopyroxenes from the Skaergaard Intrusion: implications for the subsolidus cooling rates and premeabilities

Article Abstract:

The quenched cation ordering states of five orthopyroxene crystals have been determined from the marginal border group and the lower zone a and b of the Skaergaard intrusion. These data help in retrieving the closure temperatures of Fe-Mg ordering and cooling rates. Cooling rates strictly apply to temperatures around 340 to 400 degree celsius of the ordering states. The results of cooling rates agree with a thermal model computed using an average permeability of 10 to the -12th power square centimeters.

Crystals, Intrusions (Geology)

---

Volume and grain boundary diffusion of calcium in natural and hot-pressed calcite aggregates

Article Abstract:

Calcium is the slowest volume diffusing species in natural in hot-pressed calcite aggregates. The calcium grain boundary diffusion rates in natural and hot-pressed calcite aggregates are similar. Activation energy for calcium grain boundary diffusion is nearly 2/3 of the activation energy for volume diffusion. Calcium grain boundary diffusion rates are six times faster than the volume diffusion rates over the temperature range of the experiments.

Observations, Calcium, Calcium (Chemical element), Diffusion, Diffusion (Physics), Calcite

---

Similar abstracts:

• Abstracts: Present-day motion of the Sierra Nevada block and some tectonic implications for the Basin and Range province, North American Cordillera
• Abstracts: Mixed Caledonian appinite magmas: implications for lamprophyre fractionation and high Ba-Sr granite genesis. The relationship between E- and N-type magmas in the Baffin Bay lavas
• Abstracts: Fluid composition and evolution in coesite-bearing rocks (Dora-Maira massif, Western Alps): implications for element recycling during subduction
• Abstracts: Basalt evolution at low pressure: implications from an experimental study in the system CaO-FeO-MgO-Al2O3-SiO2
• Abstracts: Timing and origin of midcontinent rift alkaline magmatism, North America: evidence from the Coldwell Complex. Volatiles associated with the alkaline-carbonatite magmatism at Alno, Sweden: a study of fluid and solid inclusions in minerals from the Langarsholmen ring complex

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.