Dinosaur Dreaming

2002 preliminary field report

Lesley Kool

The Flat Rocks site, near Inverloch on the south-east coast of Victoria was discovered by a group of researchers in 1991 who had been systematically prospecting the coastline between San Remo and Inverloch since 1986. The site is only one of a number of fossil localities along this part of the Victorian coastline, but it contains the biggest concentration of Early Cretaceous fossil bones found so far. The fossils are preserved in a series of conglomerates sandwiched between thick underlying mudstones and overlying sandstones.

The conglomeratic layers represent the beds of ancient streams and rivers that flowed in this area about 115 million years ago, and can be seen outcropping in many places along the coastline. As these outcrops are slowly eroded by the continuous ebb and flow of the tides new fossil bones become exposed, which makes periodic reprospecting very important.

A small amount of prospecting occurs during the field season, but we tend to concentrate on the major excavation. It is up to people like Mike Cleeland, a geologist who lives on Phillip Island, who along with a small band of fellow enthusiasts, spends his weekends combing the rocky outcrops, looking for newly exposed bones. Results this year have been exceptional as you will read in Mike's report.

We began the Dinosaur Dreaming 2002 field season with a definite plan in mind, but after only a week into the dig circumstances occurred which led us to abandon our original excavation and continue in another area. The plan was to excavate from the lowest conglomerate layer, just above the underlying mudstone and remove a wedge shaped section of the fossil layer along the most westerly boundary.

By the end of the field season we hoped to have a complete stratigraphic column from the just below the overlying sandstone layer to the underlying mudstone layer, showing as many of the conglomerate layers in between. Unfortunately we were unable to realise these goals, but the change in plans led to the discovery of two more tiny mammal jaws as well as a number of other exciting finds.