Laboratory Studies on the Role of Maine Colloidal Organic Material (COM) in the Scavenging of Thorium

小行星9416088 传统观点认为钍与所有非水相配体反应（即，大颗粒和胶体）中的含量，其中钍在这些配体中的分布与配体浓度成比例。 然而，有新的证据表明，钍与各种成分的反应不同， “粒子”池的元素。 这一证据表明，钍可能在海洋胶体物质（COM）池中高度分馏，因此，在沉积物中具有复杂的路径。 COM的服务器 例如，最近的工作指出了海洋胶体行为的一个令人困惑的方面：根据U-238/Th-234不平衡估计的胶体周转时间对于所有分子量组分都相对较短：取决于环境，几周或更短;相反，14 C数据产生了低分子量胶体的旧表观年龄和较高MW组分的现代年龄（Santschi等人，1994年）。 了解钍和COM组件之间的化学关系应该提供访问钍作为碳循环内的组件的示踪剂。

9416088 HONEYMAN Conventional wisdom has held that thorium reacts with all non- aqueous phase ligands (i.e., macroparticles and colloids) to the same degree with thorium distribution among those ligands being proportional to ligand concentration. There is, however, emerging evidence that thorium reacts differently with the various compo- nents of the "particle" pool. This evidence suggests that thorium may be highly fractionated within the pool of marine colloidal material (COM) and, thus, has a complicated path through the res- ervior of COM. For example, recent work points to a puzzling aspect of marine colloid behavior: colloid turnover times estimated from U-238/Th-234 disequilibrium are relatively short for all molecular weight fractions: several weeks or less depending on the environment; in contrast, 14C data yields old apparent ages for low molecular weight colloids and modern ages for the higher MW fractions (Santschi et al., 1994). Understanding the chemical relationship between thorium and components of COM should provide access to thorium as a tracer for components within the carbon cycle.