Class notes
College aantekeningen Paleoenvironments (GEO3-4312)
- Course
- Institution
Een samenvatting van alle colleges. Dit is alles wat je moet leren voor het tentamen.
[Show more]
1 review
By: svenbuitenhuis7 • 10 months ago
Seller
Follow
melaniebroos1999
Reviews received
Content preview
Lectures summary PaleoenvironmentsLecture Natural environmental archives and coring methods
Source of information extending the instrumental period back in the time
• Types of environmental records
• Sampling techniques
• Sedimentation processes
• Sediment characterisation
Most visible environmental history: glacier retreat
Most glaciers are retreating
Natural environmental archives:
- Oceans > chemical in ocean, ocean cores
- Tree rings
- Pollen
- Corals
- Lake levels
- Ice cores
More information on the north part of the world because they start researching there
In the lake all kind of inputs
,Ash layers we can use for dating.
Climate geology and land use control lake processes (mixing, decomposition, chemistry)
Sediments reflect controls and in-lake processes.
Coring methods
Choice depends on research question and aim of the study
- Long corers (long records); multiple segments, larger setups
- Short gravity corers (human impact, proxy calibration): flexible, Transportable
- Freeze cores (sedimentation patterns, calibration, undisturbed sediment-water interface)>
how organisms live or detailed layers of sediment.
Methods to get a core
Russian corer: simple use and undisturbed samples mobile set up but short sections. is for not to
sandy sediments for lakes for example. You put in in the sediment and give it a half turn, when you
pick it up it is close off from the environment like a big sculp.
Piston corer: (for long records) you have a piston in a tube and bring it down to the sediment. By the
pistons the sediment can’t fall out. You can take multiple sections.
,Freeze corers: a blade that is filled with liquid nitrogen so the sediment is frozen around the blade.
You have a core with very detailed layers that are not disturbance.
Clymo peat core: large volume, limited length, important for macrofossil studies. Handy if you work
in peat (turf).
Sedimentation
- Variability of accumulation (ophoping) rates
There can be a higher sediment input or disturbance, mixing of lake
- Particle distribution not homogeneous: e.g. Stocke’s law (rate of settling of spherical particles
in a viscous fluid of know density) > particles difference from size
Particle size = energy level, larger particles deposit rapidly, clay relatively resistant to erosion.
, - Single events (slumps, turbidites, homogenites) = high deposition, short time
A flood that creates a clear debris layer.
- Bioturbation
Different organism bioturbated in different ways
- Zonation ( lake to bog succession)
Transition from one stage to the lake to something else, lake can fill up with vegetation.
Lakes develop into swaps and bogs
Different peat types
- Minerotrophic swap (common in Netherlands coastal aeras)
o Ground water fed
o Nutrient rich
o Below/at water level
o Fresh to brackish
- Forested swap/carr (forested wetland)
o Nw Europe: alder carr (broekveen)
o Tropics: cypress swamp
o Ground water fed
o Nutrient intermediate
o At water level, along streams & levees
- Ombotrophic (raised) bog
o Rain water fed
o Nutrient poor
▪ Rare plants
o Up to 60 % water
Lake > filling in > overgrowing > fen > bog
The water table is raised above the ground water table.
- Hiatus
Found out that lake miss layers by data analysist
Causes hiatus
• Climate: drier/wetter, lake level change
• Climate: events (floods)
• Tectonic: subsidence, earth quake
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller melaniebroos1999. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $6.96. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67474 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now