Essays about: "40Ar 39Ar"

Found 5 essays containing the words 40Ar 39Ar.

1. 1. Field relations, petrography and 40Ar/39Ar cooling ages of hornblende in a part of the eclogite-bearing domain, Sveconorwegian Orogen

   University essay from Lunds universitet/Geologiska institutionen

   Author : Nasim Mozafari Amiri; [2013]
   Keywords : Sveconorwegian; retrograde metamorphism; eclogite; Svarten Zone; ductile deformation; Ar-Ar dating.; Earth and Environmental Sciences;

   Abstract : High-pressure metamorphism and deformation of the Ullared Deformation Zone (UDZ) in the Eastern segment of the Sveconorwegian Orogen, southwest Sweden is evidenced by ~ 970 Ma retro-eclogite found in association with upper amphibolite and high-pressure granulite facies rocks. Petrographic, structural and geochronological studies of the UDZ were carried out to better understand the regional metamorphism and deformation history with focus on a ~N-S trending part of the zone influenced by a late stage of deformation during Sveconorwegian orogeny, namely the Svarten Zone. READ MORE

3. 2. Robust U-Pb baddeleyite ages of mafic dykes and intrusions in southern West Greenland : constraints on the coherency of crustal blocks of the North Atlantic Craton

   University essay from Lunds universitet/Geologiska institutionen

   Author : Mimmi Nilsson; [2009]
   Keywords : geography; geology; West Greenland; mafic dykes; U-Pb baddeleyite; crustal blocks; North Atlantic craton; Earth and Environmental Sciences;

   Abstract : Popul�rvetenskaplig sammanfattning: Studien �r en del av ett st�rre projekt (LIP-projektet) som syftar till att med hj�lp av exakta dateringar av diabasg�ngar rekonstruera kontinenternas l�ge f�r c:a 2.5 miljarder �r sedan. READ MORE

4. 3. Variations in impactor flux to the Moon and Earth after 3.85 Ga

   University essay from Lunds universitet/Geologiska institutionen

   Author : Sanna Holm; [2008]
   Keywords : the Moon; impact crater; impactor flux; OMAT-profile; månen; impaktkrater; impaktfrekvens; OMAT-profil; Earth and Environmental Sciences;

   Abstract : An impact crater is the result of a collision between a large and a smaller body. On Earth most of the cratering record has been erased because of tectonic processes and weathering. The Moon, however, displays a nearly complete record of impact events over the last 2 Gyr, and evidence of impact cratering events nearly 4 billion years old. READ MORE

5. 4. 40Ar/39Ar datering av basalter i Skåne, S Sverige : bevis för två pulser vid 191-178 Ma och vid 110 Ma, samt deras relation till uppsprickning av Pangea

   University essay from Lunds universitet/Geologiska institutionen

   Author : Ingemar Bergelin; [2006]
   Keywords : Skåne; basalt; jura; krita; geokronologi; 40Ar 39Ar; geokemi; Scania; Jurassic; Cretaceous; geochronology; geochemistry; Earth and Environmental Sciences;

   Abstract : Under karbon och perm sammansmälte huvuddelen av jordens kontinenter till en gigantisk landmassa som fått namnet Pangea. Denna blev efterhand instabil och började mot slutet av trias, men framför allt under Jura, att fragmentera i ett antal mindre kontinentala plattor. Detta skedde under omfattande och ibland våldsam vulkanism. READ MORE

6. 5. Retrograded eclogites of the Richarddalen Complex, NW Svalbard : petrology and P/T-conditions

   University essay from Lunds universitet/Geologiska institutionen

   Author : Ros-Mari Hesbøl; [1996]
   Keywords : Svalbard; geography; geology; retrograded eclogites; Richarddalen Complex; petrology; P T-conditions; Earth and Environmental Sciences;

   Abstract : At least three terranes have been identified in the Svalbard Caledonides, each one having independent structures and tectonothermal evolution. On Biskayerhalvöya in the Northwestern Terrane, eclogites, located within deformed igneous basement rocks, have been dated by the U-Pb zircon method to c. 625 Ma. READ MORE