求翻译：(4)顶底板侵入型，岩浆沿煤层顶底板同时侵入，受岩浆高温性和推挤性影响．上下岩床之间保存有藕节状、串珠状或鸡窝状大小不等的煤体。岩脉一般沿断层裂隙带侵入，岩床则顺煤层侵入。并吞蚀煤层，致使煤厚变薄，其程度随侵入的大小、形态及部位而异，并使煤层结构复杂化，常呈似层状或无规则．同时夹矸增多。煤层与岩浆岩的接触带常出现焦化，煤层坚硬致密，光泽暗淡．断口粗齿状，俗称。犬齿煤”；岩墙直接侵入煤层的地方全部吞蚀了煤层。但其附近的吞蚀程度则不同，当岩墙以小规模是什么意思？

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(4) top-bottom plate, and magma intrusion along the top seam, and the same time the magma intrusion into high temperature, and pushed up or down, affects sill . saved between section A and beaded ribbon, string or bird's nest-shaped and vary in size. veins in a rock cleft along fault lines, with inc