Question

explain how palynological analysis can be combined with other forms of biological proxy data in a multi-proxy analysis of Quaternary environments and events

Answer 1

These proxy data are preserved physical characteristics of the environment that can stand in for direct measurements. Paleoclimatologists gather proxy data from natural recorders of climate variability such as tree rings, ice cores, fossil pollen, ocean sediments, corals and historical data. By analyzing records taken from these and other proxy sources, scientists can extend our understanding of climate far beyond the instrumental record.

Historical documents, which are one type of proxy data, can contain a wealth of information about past climates. Observations of weather and climate conditions can be found in ship and farmers’ logs, travelers’ diaries, newspaper accounts, and other written records. When properly evaluated, historical documents can yield both qualitative and quantitative information about past climate.

Another type of proxy data, corals build their hard skeletons from calcium carbonate—a mineral extracted from seawater. The carbonate contains isotopes of oxygen as well as trace metals that can be used to determine the temperature of the water in which the coral grew.

All flowering plants produce pollen grains, which are another type of proxy data. Scientists can use the distinctive shapes of pollen grains to identify the type of plant from which they came.

Located high in the mountains and near the poles, ice—another type of proxy data—has accumulated from snowfall over many millennia. Scientists drill through the deep ice to collect ice cores, which often have distinct layers in them.

Trees and their unique rings also serve as proxy data. Because climate conditions influence tree growth, patterns in tree-ring widths, density, and isotopic composition reflect variations in climate. In temperate regions where there is a distinct growing season, trees generally produce one ring a year, recording the climate conditions each year.

Another type of proxy data can be found on the floors of the Earth’s oceans and lakes. Billions of tons of sediment accumulate in ocean and lake basins each year, providing a vast amount of information about the environment in them.