Natural Artesian Spring.
Alongside Maruia River up in the bush across the river is an artesian mineral hot water spring.
Artesian mineral springs are usually found along earth crust fault lines. There are many more springs along this faultline on the river edge and in the bush but usually are not visible unless you search really hard, some not springing out the surface but ozing through the soil and rocks. There is one of those near Boyl's Creek Camp along this highway South of here, but a landslide covered the main one there.
The Alpine Fault side fault traverses up the valley and GNS say that the last major earthquake in the area was in the 1800s and had a ground shift of 30cm with an estimated 7.5 mag quake.
Ground water deep n the earth crust is heated by the magma causing the very hot water to rise to the surface. Each spring will have slightly different flow rates, temperatures and mineral compounds. The Maruia spring temperature averages 56 degress C at a rate of 500,000 litres daily. The colour of the water can change through the day from blackish, clear, through to blueish.
In this process various natural minerals are in the water. Sulphur (S), Boron (B), and Sodium (Na). This makes the water slightly alkaline with a pH of 7.3. Unfortunately you do not get to see where the spring is across the river as that area is fenced off with signs prohibiting access.
Park at the suggested parking spot on the river side of the highway. Park well off the road as it gets many large trucks going past. I suggest not to walk up the road as there is not much walking space at road side. Go down to the braided river and walk up beside it. There may be places you need to walk into the water or jump across, depending on time of year and rain fall. I suggest this be done only in daytime NOT nighttime.
The posted coordinate will take you to one end of the suspended pipework.
As you would be aware there are pools close by on private land so unless you are a guest do NOT park or enter.
To log this earth cache there is no need to purchase anything or participate in the activities.
Logging requirments.
1. Close to the GZ you may notice something special which is associated with geothermal springs. Use you noses to snif this out. Please report on your observations to the CO what the smell reminds you of, then give your opinion to which of the elements in the spring water would cause this natural occurence.
2. Can you see any natural visible evidence that a spring exists in this area.
3. Touch the river water downstream of GZ with your hand. Then upstream. Compare these and give your opinion if the downstream water is slightly warmer. If so, or not please share an opinion.
4. A photo with: you, part of you, your caching name, your device at the pipe that goes across river.
Send your observations to the CO in the message centre and log when you get to cell coverage. Please post you photo with your log.
Do NOT include any of these observations in your online log.
Recommended nearby interesting cache.
GCHP7D My Fault (West Coast) a simple multi.
There are other traditionals close by some tricky others with great views