| However, there have been at least four significant glacial episodes prior to the Pleistocene glaciations. |
| Their study by others led to the discovery of multiple glaciations, separated by interglacial periods. |
| Over the last half-million years or so, warm interglacial periods have been much shorter than the cold glaciations, lasting on average only 10,000 years. |
| Then came a warmer period between glaciations, and the stalactite grew. |
| Minor glaciations may also have taken place in the earlier Ordovician early Silurian and late Devonian. |
| We've had glaciations and we've had warmer periods, and vegetation would creep back as the glaciers were retreating. |
