# Diatomaceous Soils and Advances in Geotechnical Engineering--Part I
## 4 Discussion  
Diatomaceous soils (DSs) constitute an emerging line of research; their presence in multiple places, the possibility of finding them in marine or lacustrine environments (current or desiccated), and their variable thicknesses and depths entail geotechnical evaluation that goes beyond typical characterization procedures. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Origin** & **Soil** & \(\Phi^{\prime}\) & **Recorded stress** & **Author** & **Comments** \\ \hline \hline \multirow{4}{*}{Daboratory and in situ test results revealed that the diatom deposit at Buck Creek Bridge is stiff and has high shear strength. Elastic displacements are very high for the case of closed-toe piles driving (very low resistance is observed during driving), which conflicts with the measured high stiffness and strength of the soil. Isotropically consolidated undrained triaxial test. \\  & Undisturbed samples & - & \(\blacksquare\) & \(\blacksquare\) \\  & Undisturbed samples & - & \(\blacksquare\) & \(  
The primary time frame of study has been identified since 1992. A second literary production peak has evolved since 2012. Some authors stand out as referents for consultation ([PERSON], [PERSON], [PERSON], [PERSON]), since they generated the first indications regarding the lines of recognition of the DS and their research proposals are still valid. In the current scenario, some results have deepened the understanding of this behavior, particularly in coastal deposits ([PERSON], Arenaldi). The lines of study in DS can be categorized into two large blocks. The oldest concentrates on particle size distribution, limits of consistency, oedometric tests, and shear resistance tests performed under static conditions. The most recent line covers shear tests conducted under dynamic conditions, analyses with microscopy, and modeling. To date, many authors recognize the need to deepen research on aspects such as secondary consolidation due to the breaking of frustules, the phenomenon of particle interlocking during the application of shear stresses, the elastic properties of microfossils and their resistance before breaking (determination of the yield point), and the generation of pore pressure during construction processes, among others. Diatom fossils are recorded in multiple types of soils, such as those with a high organic content, clayey matrices, and sandy silt media. The effective friction angles obtained in DS through triaxial tests fluctuate between 22\({}^{\circ}\) to 65\({}^{\circ}\) depending on the frustule content and other variables. The shear resistance has been evaluated in unaltered, reconstituted, and artificial samples, with some authors noting that the behavior can be different depending on the origin and treatment of the samples. The higher the content of frustules is, the higher the number of voids will be, given the inter and intraskeletal portal structures. This situation is associated with a broad absorption or encapsulation capacity for water, which directly affects the determination of the consistency limits. The frustules present strain resistance at the micrometric level when stress imposition exists. When the frustules' yield limit is exceeded, DS presents volumetric variations. These are associated with processes such as secondary consolidation and collapse. Understanding the DS requires recognizing the environmental, biological, taphonomic, and geological conditions surrounding the generation and deposition of the frustules. This literary review has allowed us to identify the imprecise use of terms relating to DSs, since their physical characteristics (silica content, porosities, geostatic stresses, and formation temperatures) are not considered when categorizing them. Suppose that geotechnical behavior uncertainty is added to the above. In that case, it becomes necessary to establish a technical framework for classifying fossiliferous soils independent of the one currently applied to organic and inorganic soils.