Luya Mountain is about 100 meters high, and there are springs on the cliff all the year round. Usually spring water pours like rain and fog, and there are heavy rains and flash floods in summer and autumn. The torrent poured down from the cliff, hanging in the sky like a thousand-foot bead curtain, and its sound was like thunder. If there is direct sunlight, it will be extraordinary and colorful. Xu Xiake, a traveler in the Ming Dynasty, described in detail in the Diary of a Visit to Songshan Mountain: "From the northeast of Yue Temple, it was several miles across Tuo, and then turned to Luya Temple. A few martial arts outside the temple, that is, a stream, fell into the stone gorge. On both sides of the gorge, it becomes summer. After the temple was built upstream, a cliff was built at the bottom of the canyon, like a half-gauge ring. The upper cover is cut off, the flying spring fails, the dance drags, and the valley is slightly scattered, which can be used as a Wuyi water curtain. In this case, it is great to get water. Water can get stones, and stones can help water, but they can't make water fly. It is better to compete with Yi. " Xu Xiake compared Luya Waterfall with the water curtain of Wuyishan and thought Luya Waterfall was "superior". Yuan Hongdao (1568 ~ 16 10), a contemporary writer, described it as: "The left and right walls of the stream are all white stones with dark texture, similar to the paintings of two grandsons in central Sichuan". His word "Morang Stone" is still on the cliff by the pool.
The rocks on both sides of Lisi River are mostly quartzite and schist in the lower part of Wu Zhiling Formation of Songshan Group in Proterozoic, and the strike of strata is NE-SW, and Lisi River intersects with the strike of strata. Due to the development of small folds in the stratum, the quartzite of Luohandong Formation below it is exposed to the surface twice. Luya is produced in this hard quartzite with an inclination of about 65438+08.
More than 2 million years ago, in the early Pleistocene of Quaternary, a great ice age occurred in the northern hemisphere. At that time, the climate was very cold and there was a lot of snowfall. Continental ice sheets have been formed in high latitudes in the northern hemisphere, such as Greenland ice sheet, Lauren ice sheet, Scandinavian ice sheet and Siberia ice sheet. During the maximum glacial period in Quaternary, the glacier area reached 43.73 million square kilometers, and the total amount of glaciers was about 76.97 million cubic kilometers. If all the ice melts into water, the sea level will rise by 65.438+0.97 meters ... At this time, Songshan is in the mid-latitude area, and mountain glaciers were formed at that time. The source of the glacier is at the upper part of the mountain, and the snow flows down the valley under the action of gravity and pressure all year round. There are a lot of chips and stones on the surface, inside and bottom of the ice body. It is called abrasion to file the ice bed and bedrock on both sides. Glaciers can be excavated to obtain materials in the ice bed, which is called excavation erosion. Glacier valleys are formed under the action of constant abrasion and excavation. Glacier troughs and valleys are different from the "V" shaped valleys formed under the action of running water, and are "U" shaped, so they are also called U-shaped valleys. When the glacier flows to the gentle foothills, the speed slows down, the ice and snow melt, and the mud, sand and gravel it carries accumulate, which is called moraine. The source of Songshan glacier is the top of the mountain, and the main remains are ice buckets, blade ridges and tinder. The shape of the ice bucket is like an armchair, which is located in the upper part of each glacier valley. Blade ridge, also called fish ridge or fin ridge, is a kind of ridge with two steep slopes and sharp as a blade. It was formed by the backward erosion of ice buckets and ice chambers on both sides of the mountain during the glaciation. Paomaling and Longshan are both ridged landforms. Velvet is a pyramid-shaped peak eroded backward by many ice buckets, including Paomaling, Songshan and Longshan Ridge. There are many glacier canyons on the eastern slope of Songshan Mountain, among which Lisi River and Longtangou are two typical glacier canyons. Although it was transformed by running water for more than one million years after the ice age, it can still show the original appearance of the U-shaped valley. In the valley, you can see several terraces with alternating scarps and depressions, which are ice steps formed by glacier excavation. On the rock walls on both sides of the ravine, we can find the stripes formed by the friction and scribing of gravel stones in the glacier, which are called glacier scratches, generally in the shape of "nail head and mouse tail", which is different from the stripes formed by mudslides and landslides. Luya Mountain is a typical ice bank in glacier canyon.
Moraine in Songshan area is distributed at the top of many ridges and hills north of Heying River at the southern foot of Songshan Mountain. It is a mixture of clay, sand and gravel without sorting, and there are many huge glacier boulders.
Luya Waterfall is a masterpiece of glaciation and a gift from that catastrophic event.