Theology, News and Notes - Vol. 42, No. 03

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1123/thumbnail.jp

Theology, News and Notes - Vol. 12, No. 02

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1024/thumbnail.jp

Theology, News and Notes - Vol. 13, No. 03

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1026/thumbnail.jp

Theology, News and Notes - Vol. 15, No. 02

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1034/thumbnail.jp

Theology, News and Notes - Vol. 22, No. 05

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1055/thumbnail.jp

Theology, News and Notes - Vol. 11, No. 03

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1188/thumbnail.jp

Theology, News and Notes - Vol. 13, No. 04

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1027/thumbnail.jp

The Norumbega Fault Zone, Maine: a mid-to shallow-level crustal section within a transcurrent shear zone

From studies of structure, metamorphism, and geochronology we have evidence that the Norumbega Fault Zone represents a transition from mid- to shallow crustal levels in a dextral, transcurrent shear zone within the northern Appalachian Orogen. The Norumbega Fault Zone strikes parallel to the orogen (northeast-southwest), is ~5 to 30 km wide, and is characterized by distributed ductile dextral shear fabrics in the southwestern section with a transition to brittle fabrics toward the northeast. Within the zone of distributed shear, deformation is partitioned into local zones of very high strain. Upright, isoclinal folds are common in areas of high and low strain. Metamorphic grade decreases from amphibolite facies in the southwest to sub-green schist facies in the northeast. 40Ar/39Ar mineral ages from recrystallized minerals in a high strain zone, regional cooling ages in areas of lower strain, and metamorphic textures are consistent with a polyphase history of deformation. We interpret a younging trend in 40Ar/39Ar cooling ages toward the northeast, together with the deformational fabrics andmetamorphic features, to represent exhumation of the southwestern section of the Norumbega Fault Zone from mid-crustal levels during the polyphase history of this transcurrent zone. The Norumbega Fault Zone may therefore serve as a model for deformational processes at mid- to shallow crustal levels in active strike-slip systems. RÉSUMÉ Des études de la structure, du métamorphisme et de la géochronologic nous fournissent la preuve que la zone faillée de Norumbega représente une transition des niveaux crustaux moyens à des niveaux peu profonds dans une zone de cisaillement transversal dextrale à l'intérieur de la partie septentrionale de l'orogene appalachien. La zone faillée de Norumbega suit une direction paralléle a l'orogéne (nord-est-sud-ouest); die a cinq à 30 km de largeur; et elle est caractérisec par des structures cisaillées dextrales déformables se ramifiant dans la section sud-ouest avec une transition a des structures cassantes vers le nord-est. A l'intérieur de la zone de cisaillement ramifié, la déformation est divisée en zones locales de très forte contrainte. Les plis droits isoclinaux sont courants dans les secteurs de forte et faible contrainte. L'intensité du métamorphisme décroit d'un faciès à amphibolite dans le sud-ouest à un faciès secondaire de schistes verts dans le nord-est. Les périodes minérales 40Ar/39Ar des minéraux recristallises dans une zone de forte contrainte, les périodes de refroidissement régional dans les secteurs de faible contrainte et les textures métamorphiques correspondent à une orogénese polyphasée. Nous interprétons la tendance de rajeunissement dans les périodes de refroidissement 40Ar/39Ar vers le nord-est, de même que les textures de déformation et les caractéristiqucs métamorphiques, comme une exhumation de la section sud-ouest de la zone faillée de Norumbega depuis les niveaux crustaux moyens pendant l'histoire polyphasée de cette zone transversale. La zone faillée de Norumbega pourrait, par consequent, servir de modèle pour les processus de déformation aux niveaux variant de moyens à peu profonds dans les systèmes a décrochement. [Traduit par la rédaction

Theology, News and Notes - Vol. 25, No. 04

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1065/thumbnail.jp

Theology, News and Notes - Vol. 23, No. 04

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1060/thumbnail.jp