Formation mechanism of milky lake hot spring in Lengshuikeng( 冷水坑)

The formation of milky lake hot spring in Lengshuikeng ( 冷水坑) at least include the following three mechanisms:

1.    Mass change effect in hot water

The Volcanism(火山作用) itself will generate hot liquid (or (hydrothermal熱液), and the hot igneous(火成岩) will also heat the underground water simultaneously.  The mixing of hydrothermal and generated hot underground water created the hot ore fluids(熱水礦液). Hot ore fluid under the high temperature and pressure condition at deep underground will be fused with more metal ions.

These metal ions will be elevated along the faults and fracture zones(斷層和破碎帶)of the rock.

When hot ore fluids flown through rock fractures(岩石裂隙), and elevated to a shallower location, the exerted temp. and pressure will be getting lower; the solubility(溶解度)of metal ion in Hot ore fluids will be lowered at the same time. Therefore the supersaturated(過飽和) metal ions will be precipitated at the crack or surrounding rock fractures. Hot water mineralization熱水礦化作用phenomenon will be generated accordingly. If sufficient minerals precipitated and accumulated, Orebody(礦體) will be formed at the end. During the upwelling(上湧)process of said hot ore fluids, in addition to hot water mineralization happening, the rock texture(岩石質地) will be changed as a result from the physical or chemical reaction between high temperature/strong acidic hot ore fluids and rocks. We call it Mass change effect

(換質作用)in Geology. 

Soil or rock under the long term, continuous reaction by the sprayed hot fumes, will be generated with the so called hot water Mass change effect .In this regards, soil or rock will be converted as one kind of Clay like黏土 white color mineral soil(礦土)., which is soft and easy to be collapsed.

In addition to seeing the yellow color crystals, some white materials will be appeared. The yellow crystals were formed when the gaseous sulfur in the fumed gas cooled and condensed. The white material is the resultant component of Mass change effect for the hot water.

2.    Mechanism by acidifying sulfur bacteria(硫磺酸化細菌)

There’s one kind of specific bacterium, acidifying sulfur bacteria, with the name of Sulfur Chi (硫磺芝)existing in the milky late of Yang- Ming Mountain.

This biological creature, a high temperature resistant bacterium, could survived between the temperature ranges from 30 to 80 degree centigrade.

Lengshikeng ( 冷水坑)categorized as a cold spring, its temperature is appropriate for this kind of bacterium to survive.  Sulfure Chi (硫磺芝) could secrete(分泌) jelly like material, and combined with sulfur, then dissociate sulfur crystals. Finally they are aggregated and formed as the white color precipitants. That’s the reason why to make the lake appear as milky white color. And the swamp at the bottom of milky lake will be sprayed with the gaseous sulfur compound. The ionized sulfur particle will make the lake water turbid.

After precipitating, soil type mineral layer will be formed at the water

bottom.  Sulfurous soil will be appeared as the yellow white or light

gray color at the end. And its sulfur content will be ranged from 20 % to

4 0%.

 3.The precipitation mechanism of sulfur and sulfate minerals

The burst mouth of the sulfur will be mainly with precipitated type sulfur mineral deposit. Sulfur crystals will usually be appeared in volcano active area or at hot spring zone. The sulfur in Yang-Ming Mountain and Beitou area, is generated via the direct condensation of volcanic gas. After sulfur formed at the earth’s surface, it will be reacted with many kinds of metals, to form sulfate minerals with water contents such as plaster, and alunite (明礬石 ), etc.  The mineral as formed will be precipitated together with sulfur particles, then sink in the lake to form the sulfur mineral deposit.