The two shall eventually meet. The coordinates are offset 10’ to 15’ because of poor readings under the trees. After your find continue on another 100’ to a good view of the confluence and perhaps some good swiming on a hot day. Watch for rattlesnakes.
Cache Creek canyon exposes the layered Great Valley Sequence rock formation which you have, no doubt, been looking at coming from either direction. The mountains west of here are different in that they are essentially the scrapings from off the ocean floor as it slid under the continental plate in the subduction process and mixed with the sandstone rock that eroded off the ancient Sierras.
When subduction stopped, the Coast Ranges continued to rise, or rebound. As they did so they lifted this layered and previously undistrubed sequence of rocks up from the the ocean floor. The rocks you are seeing are laying on top of that jumbled mess of rocks to the west that is causing all the commotion.
This canyon is best viewed with the sun at your back, especially traveling up stream in the morning. Either direction at any time of day is delightful, however.
For all geocaching anywhere in these mountains be sure to make noise before you go digging into rock piles and under bushes and trees. Speak loudly and poke with a long stick. This is snake country.