1 / 11

Distinguishing storm or fire events in historic sediments

Distinguishing storm or fire events in historic sediments. Willy Amidon, Eric Butler. Introduction. • Lake sediments record past events • Coring allows study of these records. Previous work. Brown (2000), Noren (2001) used long (6m) cores to reconstruct paleoclimate and environment

chul
Download Presentation

Distinguishing storm or fire events in historic sediments

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Distinguishing storm or fire events in historic sediments Willy Amidon, Eric Butler

  2. Introduction • Lake sediments record past events • Coring allows study of these records Previous work Brown (2000), Noren (2001) used long (6m) cores to reconstruct paleoclimate and environment - identified coarse, inorganic sediment layers - interpreted as storm events OUR PURPOSE: Distinguish fire events from storm events

  3. Goals Use short cores (< 40cm) to: • Quantify historic charcoal levels • Identify historic/prehistoric boundary • Interpret any “storm” layers found • Refine lab techniques

  4. Methods of analysis • Visual logs - Changes in color, density, grain size, debris • Loss on Ignition (LOI) - Identifies trends in organic carbon content • Charcoal analysis - Elemental analyzer quantifies elemental carbon (charcoal)

  5. Coring method • Gravity cores from canoe • Extrude in the field • Cores separated into 1 cm intervals

  6. Sample preparation • Dry samples & weigh • Digest in nitric acid - removes organic carbon • Rinse & dry, weigh • Elemental analyzer - measures elemental carbon (charcoal)

  7. Results • Incomplete digestion (SY) • Incomplete washing (SY, OG)

  8. Alternate methods • Visual log on OG core • LOI on OG core Results • Correlation between LOI and organic material • Suggests a storm/fire layer? • May also represent logging

  9. Coming soon • Elemental analysis on rewashed samples - % charcoal content • Hopeful correlation with LOI and visual log - Does increase in charcoal correlate with decrease in LOI & color change?

  10. Future work • Apply procedure to longer cores • Pb210 dating of macrofossils (wood chips) • Analyze & compare more short cores

More Related