Distributions of calcareous calthemite deposits have been widely documented, but depositional processes and the architecture of their internal fabrics are not well understood. These concrete degradation products from a case study area in western Canada have external morphologies comparable to calcite speleothems formed in natural limestone caves, but the internal microstructural architecture and mineralogy are markedly different. The mineralogy consists of mostly calcite with secondary halite and minor percentages of trona and portlandite. A novel morphogenetic model explains depositional processes resulting in calcareous crusts that follow fractures of an overlying concrete surface, and how sufficient structural integrity provided by the internal architecture supports attachment areas of tubular soda straws. Interiors of these multi-cm crusts consist of curvilinear calcite laminae arrayed as sub-parallel walls, compartmentalizing water–gas interfaces along variously interconnected conduits and basin-form chambers. Overall porosities of 40–60% or more are prevalent, in contrast to < 1% associated with externally similar drapery-form crusts deposited within natural limestone caves. Several calcite fabrics new to calthemite deposits are described, including dendritic shrubs that coalesce into concentric growth rings along central canals of soda straws.

中文翻译：

---

混凝土钙钛矿的形态和微观结构

钙质钙长石沉积物的分布已被广泛记录，但沉积过程及其内部织物的结构尚不十分清楚。这些来自加拿大西部案例研究区的混凝土降解产物的外部形态可与天然石灰岩洞穴中形成的方解石蛇眼石相媲美，但内部微观结构和矿物学却有明显不同。矿物学主要由方解石，次生盐岩和少量的天然碱和波特兰组成。一个新颖的形态发生模型解释了沉积过程导致钙质硬壳跟随上覆混凝土表面的破裂，以及内部结构提供的足够结构完整性如何支撑管状苏打管的附着区域。这些几厘米厚的地壳的内部由排列成亚平行壁的曲线方解石薄片组成，沿着相互连接的导管和盆状腔室分隔水气界面。总体孔隙率为40％至60％或更高，而与天然石灰岩洞穴中沉积的外部相似的帷幔状结壳相关的孔隙率不到1％。描述了几种新的方解石沉积物方解石织物，包括树枝状灌木，这些灌木沿苏打草的中央管汇聚成同心的生长环。1％与天然石灰岩洞穴中沉积的外部相似的帷幔状结皮有关。描述了几种新的方解石沉积物方解石织物，包括树枝状灌木，这些灌木沿苏打秸秆的中心管汇聚成同心的生长环。1％与天然石灰岩洞穴中沉积的外部相似的帷幔状结皮有关。描述了几种新的方解石沉积物方解石织物，包括树枝状灌木，这些灌木沿苏打草的中央管汇聚成同心的生长环。