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上扬子区下志留统灰岩中发育良好的与海洋风暴事件相关的腕足动物枝线贝类介壳层.它见于黔北香树园组近顶部或石牛栏组上部,由2个昙花一现的浅海土著分子拟壳房贝属(Paraconchidium)或小枝线贝属(Virgianella)以不同比例混合、非原始正常栖居方式的碎壳与灰泥共同堆积而成.单层厚度少则仅数十厘米,多则达4m多.其中的壳体皆遭遇过高能水流强烈搅动,特别是较薄的腹壳前部和背壳,更是破损严重,其形成的主要动力是风暴和海岸线形状共同导致的增水作用;据相关群落的生态位(BA2下部至BA3上部)推测,它们是近岸浅海风暴作用的产物,介壳的破碎及其堆积的疏密程度反映了近源和远源风暴成因.志留纪时处于南低纬度的黔北海域,在广海强水团到达时,加剧的能量强烈地波及到枝线贝类群落栖居的深度.多数介壳滩被风暴反复冲淘,推测其堆积时间可达数万年.
Well-developed clarithromic shellfish shell of the Brachil-fauna, associated with a marine storm event in the Upper Silurian limestone of the Upper Yangtze region, is found in the upper part of the Qingshuyuan Formation in the north of Guizhou Province or in the upper part of the Shilancao Formation and consists of two epiphytic Shallow-sea natives, Paraconchidium or Virgianella, are mixed with different proportions of non-native, normal habitat crushed shells and stucco, with a single thickness of only a few tens of centimeters , As many as up to 4m.All of the shells are subjected to intense agitation of high energy flow, especially the thin front and back shell of the belly shell, but also a serious damage, the formation of the main driving force is caused by the storm and the shape of the coastline According to the niche (lower BA2 to upper BA3) of the related communities, they are the products of the shallow coastal storm over the coast, and the fragmentation of the crust and the density of its accumulation reflect the origin of near-source and far-source storms. The retention time was in the northern Guizhou sea area at low latitudes, and the intensified energy strongly impacted the depth of dwelling habitat to the clam shell communities when the strong sea mass arrived in Guanghai. Most of the crustaceans were stormed repeatedly by the storm, suggesting that the accumulation Time up to tens of thousands of years.