Syenogranite, a type of granite that mainly contains minerals such as flesh pink potassium feldspar, white quartz, and black biotite, is the most commonly seen rock in Jiuhuashan Geopark. With flesh pink color it was formed about 125 million years ago. Here the fine-grained syenogranite on the edge and the coarse-grained syenogranite at the center can be observed. This phenomenon is the result of different cooling speed of the magma, as on the edge it cooled down faster but at the center slower.
Granodiorite, a plutonite, is an igneous rock formed from slowly condensed magma 3,000m deep down inside the earth’s crust. It is of mixed black and white colors and contains abundant hornblende and plagioclase. The granodiorite in Jiuhuashan was formed by the upwelling of magma caused by the collision between the Pacific Plate and the Eurasian Plate 140 million years ago. It constitutes the Qingyang rock body and can be found at both sides of the Jiuhuashan range.
Syenogranite porphyry, a hypabyssal rock, is an igneous rock formed from magma in shallow underground. It is of flesh pink color and contains porphyritic potassium feldspar crystals. The dyke was formed by magma upwelling and intruding into the granodiorite rock body 120 million years ago. It can be found mainly in the Jiaziling-Fangjiali area in Jiuhuashan Geopark.
Diabase is an igneous rock formed by magma cooled underground within a depth of 3 km. Because of its dark green color and high wear and corrosion resistance, it can be used as good building materials. The diabase dyke that intruded into the granite is the evidence of the crust-mantle mixing and mingling between the deep mantle-derived magma and the magma in the upper crust in the late Mesozoic (140-60 million years ago).
Monzonite granite is mainly distributed in the periphery of rock mass. It is a kind of granite with approximately equal content of alkaline feldspar and plagioclase. The intrusion age of monzonite granite is about 140 million years ago.