01 June 2011
How to Screen Wash Project 23 Matrix
Over 2000 buckets of matrix produced from Project 23 thus far and what to do with them? Reduce! Our matrix contains a lot of non-asphaltic sediment that can be washed away. Over past months Excavators have been working on a new system for screen washing, with major organizing and tool/equipment building done by Karin.
First, we choose buckets that have a lot of fine non-asphaltic sediment and soak overnight:
soaking matrix We then scoop muddy squishy matrix from its bucket into a specialized bucket with a 20 mesh (size used for micro-fossil sorting) screen on the bottom (that Karin made) and swish and break
down the fine dirt that washes into tubs of water (that Karin made, sitting on a wooden platform that Karin made)
the wash station
Box 14 had a bit of a make-over with our use of one of the fancy canopies from Media Day
the wash station
The matrix dries on screens and then is bagged. Sometimes visible microfossils are "high graded" into a capsule within the bag. One rather large recent surprise was a Nothrotheriops shastensis patella in matrix from Box 1. It's the first Shasta ground sloth found in Project 23!
A five gallon size bucket of matrix reduces down to about a gallon size bag of matrix that will later be degreased, and then we re-use buckets - yay!
from bucket to bag
In other P23 news....
from bucket to bag
In other P23 news....
Box 14 had a bit of a make-over with our use of one of the fancy canopies from Media Day
IMGP9555
Little Timmy's left lower mandible shows up near a disturbed part of the deposit
IMGP9598
An herbivore (probably bison) maxilla is revealed in Box 1
P23 1 B-1 L-6 grid progress
Little Timmy's left lower mandible shows up near a disturbed part of the deposit
IMGP9598
An herbivore (probably bison) maxilla is revealed in Box 1
P23 1 B-1 L-6 grid progress
And in the lab, Herb found two elements (occipital horns and maxilla) from a coastal horned lizard in Box 14 while sorting matrix from a block of asphaltic sand containing many small delicate bones. These are the first horned lizard bones found since 1929 in Pit A, and only the second individual ever identified at Rancho La Brea.
Posted by
Carrie
at
9:45 AM
Subscribe to:
Post Comments (Atom)
1 comment:
Sounds like Karin is an awfully handy person to have around!
Post a Comment