1. Subduction: Oceanic plates, denser than continental plates, are forced underneath the continental plates at convergent plate boundaries. This process is called subduction.
2. Sediment Scrape-Off: 海洋プレートが下降すると、海洋化石、火山灰、その他の材料など、その表面に蓄積された堆積物が蓄積され、大陸板の端に削り取られます。 This forms a wedge of sediments called an accretionary prism 。
3. Melting and Magma Generation: The descending oceanic plate experiences increasing pressure and heat. This causes partial melting of the plate, creating magma that rises towards the surface.
4. Volcanism and Mountain Building: The rising magma can erupt through the overlying continental plate, forming volcanoes along the edge of the continent. These volcanoes contribute to the growth of the mountain range.
5. Folding and Faulting: 収束プレートからの激しい圧力は、堆積物と降着のプリズムと大陸地殻の既存の岩層も折り畳まれ、断層を引き起こし、山の建物にさらに寄与します。
キーポイント：
* Accretionary prisms: These are wedges of sediments that accumulate at the edge of the continental plate due to subduction.
* 造山性： This is the process of mountain building, involving the collision of tectonic plates.
* Continental growth: 何百万年もの間、沈み込みと造山運動のプロセスは大陸の成長と肥厚につながり、海洋堆積物が大陸地殻に組み込まれています。
例：
* アンデス山： Formed by the subduction of the Nazca Plate beneath the South American Plate, incorporating sediments from the Pacific Ocean.
* ヒマラヤ： Formed by the collision of the Indian Plate with the Eurasian Plate, incorporating sediments from the Tethys Sea.
本質的に、海洋堆積物は単に大陸に「落とされた」のではなく、プレートテクトニクスの動的プロセスを通じてその構造に積極的に組み込まれています。
