+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Kinetic studies in contact metamorphic zones

, : Kinetic studies in contact metamorphic zones. Geochimica et Cosmochimica Acta 31(7): 1119-1153

Rubidium-strontium and K/Ar ages of biotite, muscovite, and potassium feldspar and K/Ar ages of hornblende from a granitic stock (2600 m.y.) near the contact with a gabbro (1050 m.y.), and Rb/Sr and K/Ar ages of biotite and K/Ar ages of hornblende from amphibolite (metamorphosed at 2600 m.y.) near the contact with a quartz dolerite dike (800 m.y.) were determined to study the effects of thermal metamorphism on mineral ages. Volume diffusion and zero- and first-order chemical reaction-rate models are used to describe the rate of loss of radiogenic Sr and Ar from these minerals: the chemical reaction-rate models may apply if the rate of loss is controlled by recrystallization. The different models give activation energies ranging from 30 to 75 kcal/mole. The loss of Ar from hornblende took place at higher temperatures than for biotite and the activation energies also may be higher. The relative stability of mineral ages in a contact zone is hornblende K/Ar > muscovite Rb/Sr > muscovite K/Ar > biotite Rb/Sr > biotite K/Ar, although for the micas the Rb/Sr and K/Ar ages are essentially concordant.


DOI: 10.1016/s0016-7037(67)80053-x

Other references

Liu, Y.T., 1962: Effect of beryllium and other bivalent cations on some intermediate reactions of glycolysis. Voprosy Meditsinskoi Khimii 8: 392-395

Gibson, T.P.; Quintanilla, A.P., 1980: The renal clearance of digoxin is dependent upon the serum digoxin concentration. The effect of alterations of serum digoxin concentrations on the renal clearance of digoxin (CDIG) was studied in seven dogs. Digoxin, 0.016 microgram/kg/min (low dose) in normal saline was infused at the rate of 1 ml/min. After 60 min of equilibr...

Chapman, S.A.; Bonshek, R.E.; Stoddart, R.W.; Jones, C.J.P.; Mackenzie, K.R.; O'donoghue, E.; Mcleod, D., 1995: Glycoconjugates of the human trabecular meshwork: A lectin histochemical study. Twelve specimens of resin-embedded human trabecular meshwork were probed with a panel of 21 biotinylated lectins, using an avidin-biotin peroxidase revealing system, in order to determine the normal pattern of saccharide expression in this tissue....

Hoffman, R.M.; Jamieson, B.D.; Bosch, R.J.; Currier, J.; Kitchen, C.M.R.; Schmid, I.; Zhu, Y.; Bennett, K.; Mitsuyasu, R., 2012: Baseline immune phenotypes and CD4+ T lymphocyte responses to antiretroviral therapy in younger versus older HIV-infected individuals. Journal of Clinical Immunology 31(5): 873-881

Jain Anant V.; Lipschutz Michael E., 1969: Shock histories of iron meteorites; an interim report. Meteoritics 4(3): 185

Finkenstaedt T.; Ewert J P., 1983: Visual pattern discrimination through interactions of neural networks a combined electrical brain stimulation brain lesions and extracellular recording study in salamandra salamandra. In freely moving S. salamandra various brain sites (n = 33) were stimulated monopolarly via chronically implanted electrodes. Stimulation of the optic tectum mainly elicited prey-catching behavior (mean lower current threshold Ilt = 9 .mu.A) and s...

Shin, H.; Ryan, A.M., 2015: Friendship networks and achievement goals: an examination of selection and influence processes and variations by gender. Interactions with friends are a salient part of students' experience at school. Thus, friends are likely to be an important source of influence on achievement goals. This study investigated processes within early adolescent friendships (selec...

Geyr von Schweppenburg, Frh H., 1910: Anthus spinoletta spinoletta L im Rheinland brutend. Ornithologisches Jahrbuch Hallein, 21 52-54

Goldstein J.I., 1986: Metallographic cooling rates; recent advances. LPI Contribution 600: D-1

An, A.S.; Akhum'ian, A.P.; Grabarnik, M.Sh.; Medvedeva, E.I., 1969: Laundering coverals that have been contaminated by creosote. Gigiena Truda i Professional'nye Zabolevaniia 13(9): 61-61