Our technique is for temperatures between about 30 and 70 degrees Celsius. This is the last cooling before a rock comes to the surface, and no other technique accesses this information. |
The helium 3 spike found in these sediments is the smoking gun that something quite dramatic happened to the interplanetary dust population 8.2 million years ago. It's one of the biggest dust events of the last 80 million years. |
We can say that the glacier was ripping out a huge amount of material and dumping it into the ocean. And rather than taking evidence from a single instant, we can for the first time see an integral of hundreds of thousands of years. So this is a new way to get at the rate at which glaciers do their work. |