好象与on one hand无关.
原文为（丢了another 一词）：While rock between two consistent strata might in one place be shale and in another sandstone,the fossils in that shale or sandstone were always the same.
翻译：尽管在两个一致地层之间的岩石在一个地方（in one place ）可能属于泥板岩（shale） ,而在另一地方（in another （place ））可能属于砂岩（sandstone）,但这些泥板岩或者砂岩中的化石则往往是相同的.