What is a plant macrofossil?

Any plant fossil preserved by one of a variety of ways, that can be seen with the naked eye, but requires the use of a binocular microscope to make satisfactory identification

What is a seed?

A small embryonic plant enclosed in a covering called the seed coat (testa), usually with some stores food available

What part of the seed preserves?

Usually the seed coat. A dicot seed has 2 cotyledons and a monocot seed had 1 cotyledon and the endosperm contains the stored food.

What does it mean when a plant macrofossil is charred?

Burning -> carbon remains -> plant preserved. Looks like black or brown. Very good identification and preservation -> sometimes preserved well enough to identify genus and species.

What does it mean when a plant macrofossil is waterlogged?

Plant was sitting in water, which stopped normal decomposition (Normally, microorganisms need oxygen to break things down). Shape is usually maintained but sometimes compressed. Color can vary. Very high identification potential.

What does it mean when a plant macrofossil is mineralized?

Original plant material is replaced by minerals. Mineral copy remains. Looks white or beige, identification is low because often much of original structure is lost.

What does it mean when a plant macrofossil is desiccated?

The plant becomes extremely dry, so it can't decompose normally. Looks very similar to the original modern plant. Very high identification potential. This is very rare

What does it mean when a plant macrofossil is impressed?

The actual plant is gone, only footprint/imprint remains. Where? mudbrick, pottery etc. Usually rare.

What does it mean when a plant macrofossil is frozen?

The plant is frozen, which slows/prevents decomposition. Identification is very high. Rare because you need unusual environmental conditions.

What is sampling?

Selecting and collecting a portion of archaeological sediment/material so that we can answer a specific research question. Avoid contamination.

How does sampling work from archaeological sections?

1. Clean 2. Describe and record the sediments/layers 3. Sample -> collect the sediment using monolith tins or sealable sample bags.

How does sampling work in peat bogs? And what are the main tools?

Peat bogs contain layers of preserved organic material. The main tools are Russian corer and Hiller corer.

How does sampling work in lake sediments? And what are the main tools?

The main tools are a Mackereth corer, which is used from a boat, the corer is lowered onto the lake sediment and it collects a column of sediment. Also used Piston corer.

How does freezing samples work?

samples may be frozen after collection when appropriate -> freezing helps preserve organic material and prevents further biological/chemical deterioration before analysis.

What happens during preparation of a sample?

After taking an archaeological sample, we need to separate the plant remains from the sediment so that we can examine and identify them

What is wet sieving?

Washing sediment through sieves to separate plant remains from dirt.

What is floatation?

Useful for recovering carbonized/charred plant remains. The plant remains float, while most mineral sediment sinks. Carbonized material is less dense, so it can float. Problem: floatation can potentially cause some botanical material to be lost.