Numerous potholes, flow-erosional grooves and troughs, and vertical arc-shaped grooves are  developed in river courses or cliff walls by the two river banks in the Jiulongdong scenic spot in  the Baiyunshan Scenic area,The pothole-dominated  river erosion heritage is widely  and densely distributed with  big size and changeable shapes.  The abundant quantity, various  types, big size, systematical  development and well  preservation make the landform  extremely rare. Therefore, the  landforms are worthwhile visit  and study. They display the  river erosion microlandform  and most beautiful scenery in  the geopark.

1 Rock step  and deep pool

The alkali-feldspar miarolitic granite has NE-extending joints and fissures. The rock step in  front of you was formed by erosion along the joints and fissures in the bedrock of the riverbed.  There are flow erosion-generated potholes and  troughs developed on the step. A deep pool  occurs in the bedrock of the riverbed below the  step, which is the erosion product of the water  falling from the step. Rock step, fallingwater,  and deep pool make it attracting scenery  composed of these river erosion-generated  landforms.

2 Waterfall-like rock

The weathering has loosed the cliff wall  composed of alkalifeldspar miarolitic granite.  The down-moving of rainwater along cliff wall  has washed away the loosed rock fragments  from the cliff wall. With time goes by, this kind  of water erosion has left many densely  distributed U-shaped rocky grooves. It looks,  from distance, just like a pouring-down  waterfall.

3 Intrusive contact relationship

Why can these two totally differently-colored rocks exist in the same place in the river valley?  This is because the place is the contact position between two different rocks. The dark colored  rock is a volcanic rock formed about 120  million yeas ago（Early Cretaceous）during a  volcanic eruption event, while the light colored  rock is an intrusive rock, alkalifeldspar  miarolitic granite, formed about 90 million  years ago（Late Cretaceous）. Here you can see  the latter intrudes into the former, showing an  intrusive contact relationship of the two rocks.

4 Footprint of Nature

The Footprint of Nature is really a basin-like pothole,  vividly similar with a footprint. It was formed by flow erosion  and sand-pebble wearing on the riverbed.

5 Group of rock wall

After long stress of the Earth’s crust, a  group of NEE-extending joints and fissures,  which are parallel to each other, has  developed in the alkali-feldspar miarolitic  granite in the Chan Stream area. Weathering,  water erosion, and gravitational collapse have  converted the granite into a series of rock  walls standing one by one, forming a  majestic sight. There are water  erosion-generated grooves, either shallow or deep, densely developed on the wall surface, just like  hanging groups of waterfalls.

6 Alkali-feldspar miarolitic granite landform and  volcanic landform

Why do the east and west sides of the Chan Stream have totally different landforms? The  reason is that the two sides have different lithology. The landform of the east side belongs to  volcanic mountain landform, while the west is granite mountain landform. The granite is stronger  than the volcanic rock in resisting weathering and therefore has steeper mountain body.

7 Love heart cave

The linked potholes are formed by the  perforation of nearby potholes because of  the enlargement and deepening of the  potholes. These linked potholes have  separated openings but linked inner walls. When the inner walls are completely  worn away, the linked potholes will become  the assembled pothole.

8 Jiulong Cave

The Jiulong Cave is a maze-like cave  formed by the accumulation of huge rock  blocks on the riverbed. The blocks were fallen  from two side cliffs of the river due to  gravitational collapse. Inside the cave, you can  see differently-shaped potholes on the riverbed  or rolling stones and may be astonished by  nature’s great power. Are you also aware of the  truth that softness （water） can overcome  strength（rock）.

9 Tongxin Cave

Due to flow erosion and sand/pebble  wearing, the deepening and enlargement of  several nearby potholes has resulted in the  thinning and penetration of the walls between  the potholes. This eventually formed linked  potholes with separated openings but linked  inner walls. The Tongxin Cave is a so-formed  linked pothole comprising three inner-linked  potholes.

10 Yao Pool

This is originally a jar-like pothole formed on the  steep bank of the river, with one side close to the  riverbed. Therefore, the out wall of the pothole was  suffered the side erosion of the river, while the inner  wall was eroded by eddy flow. This finally resulted in  the penetration of the river-facing sidewall. With the  enlargement of the penetrated hole, the jar-like pothole  gradually converted to the wall-penetrated pothole.

11 Feitian Well

The Feitian Well is a huge wall-penetrated jar-like pothole with a diameter of about 23 m and  a depth of 38 m. The well is the product of both flow erosion and eddy side erosion. There are  habitaclelike pits developed on the inner wall at three levels, 5 m, 6～8m, and 10～15m  respectively from the well bottom, suggesting the stronger side erosion of the eddy flow once at  the levels. The bottom of the well has eight single or assembled potholes. The big one has a  diameter of 3m, but small one only 0.5～0.8 m.

12 Water erosion-generated groove

The weathering has loosed the cliff wall composed of alkali-feldspar miarolitic granite. The  down-moving of rainwater along cliff wall has washed away the loosed rock fragments from the  cliff wall. With time goes by, this kind of water erosion has left many alternately distributed U-shaped rocky grooves and curved ridges on the cliff wall.

13 Hulu（Calabash-like）Pool

There were several nearby potholes distributed on the  bedrocks of the riverbed along current direction. The river  erosion further caused the lowering of the front and back walls  of the potholes and made them connected like linked beads.  The final penetration of the front and back walls has converted the beaded potholes to a sidewall-connected trough with curved, S-shaped sidewalls.