Visar resultat 1 - 5 av 233 avhandlingar innehållade ordet Dating.
Sammanfattning : This thesis concerns different aspects of dating divergence times in phylogenetic trees, using molecular data and multiple fossil age constraints.Datings of phylogenetically basal eudicots, monocots and modern birds (Neoaves) are presented. Large phylograms and multiple fossil constraints were used in all these studies. LÄS MER
Sammanfattning : Single activities have long been places where single people can come to meet friends, build community or look for partners. The activities have relevance for studies of heterosexuality, intimacy, personal life and space. LÄS MER
3. Dealing With Reservoir Effects in Human and Faunal Skeletal Remains : Understanding the radiocarbon dating of aquatic samples
Sammanfattning : Archaeology relies on the ordering of past events to study cultural developments. This has traditionally been achieved by looking at the stratigraphic depths of materials relative to one another. In this way, chronologies of past technological progressions and stylistic changes can be built. LÄS MER
Sammanfattning : Reconstruction of former Central Asian glaciers extents can provide valuable information about past atmospheric circulation variations. These extents, often marked by terminal moraines, need to be chronologically constrained. Cosmogenic nuclide exposure (CNE) dating is widely used to directly date moraines. LÄS MER
Sammanfattning : In recent years, there has been a surge of interest in the direct dating of ore deposits using Re-Os geochronometer for the ore minerals themselves. Molybdenite has been or particular interest because it is a common ore mineral and is suitable for analysis by the Re-Os method due to relatively high concentration of both Re and Os. LÄS MER