Turtle back stone

Turtle back stone

Septarium is a special kind of diagenetic nodule with polygonal concentric rings and radial veinlets on its surface. It is named after its similar pattern.

Basic overview

It is a fissure formed by the dehydration and contraction of the nodule material precipitated in the hydrogel sediment. After that, it is filled with other minerals. Siderite like turtle spinel nodules are common in coal measure strata. This is a rare turtle back stone in the world. It is located near the seashore of Dalian Jinshitan park. It is said that there are only two turtle back stones in the world. The other one is in Canada, but it is only one third of the size of this one. There are two explanations for the genesis of this strange stone: one is that the siltstone deposited around 540 million years ago was exposed and cracked in a dry and hot climate, and its cracks were filled with green sediments, forming a network crack like a turtle's back; the other is that the rock was in a semi plastic state, and the vertical cracks were formed due to seismic action, and the rock was saturated With the aggravation of the vibration, the sediment vein grows continuously, which makes the rock strata at both ends bend and fracture, showing as a grid like crack in the layer.

source

Turtle's back stone, because the rock surface has the crack shape reticulation, resembles the turtle's back and the name. Turtle back stone is a kind of geological relic, which records a major event in geological history. There are two views on the genesis of turtle back stone

One is that the siltstone deposit, which has not been fully consolidated and diagenetic, is exposed under dry and hot climate conditions, and cracks due to water loss, and the cracks are filled by later green sediments, forming "crack like reticulation" like the back of a turtle.

The other is that: in the semi-plastic state of rock, cracks in the vertical plane are generated due to earthquake action, and the cracks are filled with silt flow full of water. With the aggravation of vibration, more and more silt is filled, which makes the rock layers at both ends bend, showing "crack like network" of dry cracks on the plane.

Address: Aotan Park, Jinshitan National Geopark, Dalian

Longitude: 122.047085

Latitude: 39.070053