Sökning: "δ13C"

Visar resultat 1 - 5 av 36 avhandlingar innehållade ordet δ13C.

1. 1. Varved lake sediments and diagenetic processes

   Författare :Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; Earth sciences; Geovetenskap;

   Sammanfattning : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. LÄS MER

3. 2. Migration in Prehistory : DNA and stable isotope analyses of Swedish skeletal material

   Författare :Anna Linderholm; Kerstin Lidén; Oliver Craig; Stockholms universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; Migration; ancient DNA; stable isotopes; δ13C; δ15N; δ34S; mtDNA; lactose tolerance; Neolithic; Pitted Ware culture; Funnel Beaker culture; Vikings; Öland; Rössberga; Birka; Björned; Archaeology; Arkeologi; Archaeological Science; laborativ arkeologi;

   Sammanfattning : The main aim of this thesis is to show how scientific methods may be used to look at migration in prehistory on the basis of archaeological material. The individuals examined represent the period 4 000 BC to 1 000 AD and have their geographical origins in various parts of Sweden.Ancient DNA analysis is employed in three cases. LÄS MER

4. 3. Consuming and communicating identities : Dietary diversity and interaction in Middle Neolithic Sweden

   Författare :Elin Fornander; Kerstin Lidén; Per Andersson; Liv Nilsson Stutz; Stockholms universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; Middle Neolithic; Neolithisation; Sweden; Baltic Sea; Funnel Beaker Culture; Pitted Ware Culture; Battle Axe Culture; megaliths; isotopes; δ13C; δ15N; δ34S; 87Sr 86Sr; radiocarbon dating; palaeodiet; mobility; interaction; identity; ethnicity; Archaeology; Arkeologi; Archaeological Science; laborativ arkeologi;

   Sammanfattning : Isotope analyses on human and faunal skeletal remains from different Swedish Neolithic archaeological contexts are here applied as a means to reconstruct dietary strategies and mobility patterns. The chronological emphasis is on the Middle Neolithic period, and radiocarbon dating constitutes another central focus. LÄS MER

5. 4. Export and sources of organic carbon in the Lena River basin, Northeastern Siberia

   Författare :Liselott Kutscher; Carl-Magnus Mörth; Per Andersson; Don Porcelli; Peter Raymond; Sebastian Sobek; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; organic carbon; DOC; POC; organic matter; NOM; DOM; POM; Lena River; organsikt kol; DOC; POC; organiskt material; NOM; DOM; POM; Lenafloden; geokemi; Geochemistry;

   Sammanfattning : Permafrost areas are considered to be one of the largest terrestrial storages of carbon. In a warming climate these areas are expected to experience changes in carbon transport to rivers and the oceans due to permafrost thawing, which could enhance erosion, change water flow pathways and increase greenhouse gas emissions. LÄS MER

7. 5. Late Quaternary climate and environmental change in the summer rainfall region of South Africa : A study using trees and wetland peat cores as natural archives

   Författare :Elin Norström; Karin Holmgren; Michael Meadows; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; paleoclimate; Late Quaternary; pollen; stable isotopes; diatoms; phytoliths; dendroclimatology; South Africa; Physical geography; Naturgeografi; Physical Geography; naturgeografi;

   Sammanfattning : This thesis contributes with information on past climate and environmental changes in South Africa’s summer rainfall region. The study is based on multi-proxy analyses on wetland peat cores and analyses of stable isotope composition (δ13C, δ18O) and wood anatomy in cross sections from subtropical trees (Breonadia salicina). LÄS MER