This is one of my favorite stops and has been since field camp, over 30 years ago. This rock is Kona dolomite, only found in the Marquette area and the swirly things in the rock are stromatolites. Stromatolites are mats of bacteria formed in shallow seas about 2 billion years ago. The layers were covered up with silt and sand, reformed, covered up again, until you have columns of rock at least 30' tall with these circular structures with differential weathering. Though you can't see it here, the fresh face of the Kona is a pink dolomite with lines of darker pink and red stromatolite layers in it. It is a beautiful polished rock and everybody takes home a piece. But nobody pounds on the columns, this is one of the very few stromatolite structures in the world that has this weathering. Geologists have been admiring this structure since Douglas Houghton described it in the early 1800s, and it was probably enjoyed much earlier than that. We also saw Mesnard quartzite and Jacobsville Sandstone in Marquette and then went to Pictured Rocks National Lakeshore to look at where the Jacobsville and the Munising sandstone come together at Sable Falls. We drank beer both evenings, told stories, caught up with each others lives, families and work, and planned the next trip before we are all too old to do this. We had fabulous cajun food on Friday night in a new restaurant in Marquette and ate pasties until they came out our ears. All in all, a good weekend. Don, thanks for sharing it with me.