A LATE PLIOCENE–EARLY PLEISTOCENE, INNER-SHELF, SUBTROPICAL, SEAGRASS-DOMINATED CARBONATE: ROE CALCARENITE, GREAT AUSTRALIAN BIGHT, WESTERN AUSTRALIA
A LATE PLIOCENE–EARLY PLEISTOCENE, INNER-SHELF, SUBTROPICAL, SEAGRASS-DOMINATED CARBONATE: ROE CALCARENITE, GREAT AUSTRALIAN BIGHT, WESTERN AUSTRALIA
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上新世晚期-更新世早期，内陆架，亚热带，以海草为主的碳酸盐岩：鱼子钙质岩，大澳大利亚湾，西澳大利亚
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发表时间：
2007
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影响因子：
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通讯作者：
Y. Bone
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文献类型：
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作者：
N. James;Y. Bone
Roe钙屑灰岩是一种厚2-3 m的未石化碳酸盐岩，形成于上新世晚期-更新世早期大澳大利亚湾中心的浅海侵蚀面上。颗粒状沉积物中富含完整的软体动物和大型共生有孔虫Marginopora vertebralis。有关节的珊瑚藻棒，完整的盘状、轮状和粟粒状有孔虫，以及无数的M.脊椎动物占主导地位的沙子大小的颗粒。一个特别明显的粟粒体是包壳形式Nubecularia sp.该单位分为两个非正式成员。我们解释的下成员，一个区域相似的软体动物丰富的相，作为一个记录的沉积在相对海平面上升浅近岸草床，可能占主导地位的Amphibolis社区生活在一个整体的亚热带环境。更大面积多样性的上段包括三个相，我们设想在一系列相邻的潮间带砂坪和海滩或潮上微生物湖泊环境的回归过程中积累。这些上新世-更新世沉积物与澳大利亚西部和南部的全新世草岸相有许多相似之处，可能代表了比今天略温暖的海洋中的堆积，其中沉积环境受到太阳辐射的加热。这个单位是一个重要的概念桥梁到旧的新生代岩石记录。
Abstract The Roe Calcarenite is a 2–3-m-thick, mostly unlithified carbonate that accumulated in shallow water at the center of the Great Australian Bight on a marine erosional surface during the late Pliocene– early Pleistocene. The grainy deposits are profusely rich in whole mollusks and the large symbiont-bearing foraminifer Marginopora vertebralis. Articulated coralline algal rods, whole discorbid, rotaliid, and miliolid foraminifers, and innumerable fragments of M. vertebralis dominate sand-sized particles. A particularly conspicuous miliolid is the encrusting form Nubecularia sp. The unit is divided into two informal members. We interpret the lower member, an areally similar mollusk-rich facies, as a record of deposition during relative sea-level rise on shallow nearshore grass beds, probably dominated by an Amphibolis community living in an overall subtropical setting. The more areally diverse upper member comprises three facies, which we envisage as having accumulated during regression in a series of adjacent intertidal sand flat and beach or supratidal microbial-lacustrine environments. These Plio–Pleistocene deposits have many parallels with Holocene grass-bank facies in western and southern Australia and likely represent accumulation in a slightly warmer ocean than today wherein the depositional setting was heated by solar radiation. This unit is an important conceptual bridge into the older Cenozoic rock record.