3-D engraving of volcanic mechanism in the Tiantai slope of Xihu Depression and its formation mechanism

Abstract

The development and distribution of igneous rocks in the Tiantai slope of Xihu Depression have an important influence on reservoir reconstruction and tectonic evolution.According to the seismic characteristics and tectonic environment in the area, two types of eruptions are divided into center type and fissure type.Based on drilling data and 3-D seismic data, the seismic amplitude and variance cube thresholding dispaly, systematically depicting 3-D spatial and temporal distribution of Tiantai of volcanics and eruption phases, revealing the igneous rocks of Mesozoic to the Miocene period in Tiantai have intermittent development more features, and enrichment of volcanism in the Tiantai slope in the southwest.Two types of eruptive modes, the central type and the fissure type, are established in the area.The establishment of these modes is of great significance for correctly predicting the distribution of igneous rocks.Finally, the genesis of igneous rock mechanism is analyzed and discussed. It is found volcanic activities and tectonic movement influence each other, volcanic distribution of space and time and the fracture also has certain configuration relations.It is believed that fissure eruption may form oil and gas migration channel, is characterized by terrigenous central type eruption is helpful to form good reservoir space.Based on this study, it will be easier to find effective volcanic reservoirs in Tiantai area, which plays an important role in indicating petroleum exploration.

Keywords

• igneous rocks
• spatial and temporal distribution
• eruption model
• formation mechanism
• tiantai slope
• xihu depression