Bayesian Surface Warping Approach for Rectifying Geological Boundaries Using Displacement Likelihood and Evidence from Geochemical Assays

This article presents a Bayesian framework for manipulating mesh surfaces with the aim of improving the positional integrity of the geological boundaries that they seek to represent. The assumption is that these surfaces, created initially using sparse data, capture the global trend and provide a reasonable approximation of the stratigraphic, mineralization, and other types of boundaries for mining exploration, but they are locally inaccurate at scales typically required for grade estimation. The proposed methodology makes local spatial corrections automatically to maximize the agreement between the modeled surfaces and observed samples. Where possible, vertices on a mesh surface are moved to provide a clear delineation, for instance, between ore and waste material across the boundary based on spatial and compositional analysis using assay measurements collected from densely spaced, geo-registered blast holes. The maximum a posteriori (MAP) solution ultimately considers the chemistry observation likelihood in a given domain. Furthermore, it is guided by an a priori spatial structure that embeds geological domain knowledge and determines the likelihood of a displacement estimate. The results demonstrate that increasing surface fidelity can significantly improve grade estimation performance based on large-scale model validation.

How to Find the Reservoir Boundaries? Integrated Application of Seismic Attribute Analysis and Welltest on the Miocene Sediments of White Tiger Field, Cuu Long Basin, Vietnam

The development of clastic reservoirs can be complicated by heterogeneity both along the section and along the strike of the formations, therefore, an extended set of studies is especially necessary at such objects, both during drilling and during production. To determine the structure of the void, seismic surveys are usually used, which are limited in scale. An additional tool for defining geological boundaries is well. Well testing carried out in a timely manner, together with the analysis of production data, attribute analysis and geophysical survey data in the open hole, made it possible to identify the heterogeneity of the drainage zone in the early stages of operation and adjust the volume of geological reserves, therefore, to predict production with the highest degree of reliability.

The Virtual Geoscience Revolution: From William Smith to Virtual Outcrop

In 1799 an English surveyor named William Smith published the World’s first geological map. This map, which covers the whole of England and Wales, fundamentally changed the way that geologists visualised the subsurface (Winchester, 2001). For the next 200 years, field geologists across the World worked in much the same way as Smith had done, tracing geological boundaries on the ground and using ink pens and coloured pencils to record the surface expression of the geology onto paper and maps. Even today, the largest single component of any undergraduate degree in the UK is a “mapping project”, where students make detailed maps of a selected area in this way. There can be very few sciences where there have been no significant changes in the basic data collection methods for over 200 years. However, since the turn of the 21st Century we have seen a quiet revolution in the way in which field data are being collected, analysed and displayed. We call this the Virtual Geoscience Revolution and it has come about in a number of discrete phases, each of which have resulted from the development of a number of distinct but parallel technologies.

Geologist in the Loop: A Hybrid Intelligence Model for Identifying Geological Boundaries from Augmented Ground Penetrating Radar

Common industry practice means that geological or stratigraphic boundaries are estimated from exploration drill holes. While exploration holes provide opportunities for accurate data at a high resolution down the hole, their acquisition is cost-intensive, which can result in the number of holes drilled being reduced. In contrast, sampling with ground-penetrating radar (GPR) is cost-effective, non-destructive, and compact, allowing for denser, continuous data acquisition. One challenge with GPR data is the subjectivity and challenges associated with interpretation. This research presents a hybrid model of geologist and machine learning for the identification of geological boundaries in a lateritic deposit. This model allows for an auditable, probabilistic representation of geologists’ interpretations and can feed into exploration planning and optimising drill campaigns in terms of the density and location of holes.

KMapper: A Field Geological Survey System

The computing power of smart mobile devices has evolved as much as the power of desktop personal computers (PCs). Accordingly, a field geological survey system capable of utilizing the performance of smart devices is needed. Thus, the objective of this paper is to introduce a system with functions to take advantage of the performance of smart devices while meeting the various requirements of a geological survey. The system integrates geographic information system functions and smart sensors to execute field geological surveys effectively and can express various collections on a map. It also includes a map editing function that allows users to edit geological boundaries and areas on a map from the touch-based interface of a smart device. The records collected can be exported for editing of the geological map on a desktop PC. The developed app can replace traditional recording media used in field geological surveying and exploration work. It can be used to acquire location-referenced measurements with smart sensors, making field work more effective.

Chronological Analysis and Remote Sensing of Craters on the Surface of Mars

In the present research, we carried out detailed chronological and compositional analyses along with detailed spectral analysis of three unnamed craters on the surface of Mars. Knowledge on chronology/age analysis and compositional analysis of Mars’ surface is essential for future manned and unmanned missions. The study area is near the landing site of previous landed missions, which could be used for future landing. The area is interesting to be studied because of its high elevation in the northeastern side and low elevation in the southern side, consisting of three major geological boundaries, i.e., Hesperian, Noachian, and Amazonian, which are further subdivided into fourteen units. Chronological investigations were carried out using the active machine learning approach and Craterstats 2.0 software, which revealed the age plot of 3.09 ± 0.04 Ga for Amazonian, 3.63 ± 0.0 Ga for Hesperian, and 3.73 ± 0.0 Ga for Noachian geological units, stating that N(1) craters’ density corresponds to the early Amazonian, early Hesperian, and late Noachian/early Hesperian periods according to the established crater density boundaries, respectively. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM)-derived browse products are used for the compositional study of the surface characteristics of Mars. A spectral investigation was performed on an unnamed crater belonging to the Amazonian period, which showed to be majorly composed of oxides as the primary mineral, indicating the spectra of hematite, boehmite, and akaganeite. A Hesperian unit-unnamed crater shows the signature of monohydrated sulfates, melilite, illite, and kaolinite minerals in the region. For the unnamed crater 3, which belongs to the Noachian period, it has diagnostic absorptions of clay minerals in their extracted spectra, indicating the sign of long-term water–rock interactions in the period. Derived chronology results and compositional studies of craters help in better understanding the geological formation units of Mars’ surface.

Thermophysical Features of the Rümker Region in Northern Oceanus Procellarum: Insights from CE-2 CELMS Data

The Rümker region is located in the northern Oceanus Procellarum, which has been selected as the landing and sampling region for China’s Chang’e-5 (CE-5) mission. The thermophysical features of the mare units are studied in detail using the brightness temperature (TB) maps (TB, normalized TB, TB difference) derived from the CE-2 microwave radiometer data. The previously interpreted geological boundaries of the Rümker region are revisited in this study according to their TB behaviors: IR1, IR2, and IR3 Rümker plateau units are combined into one single unit (IR); and a hidden unit is found on the Mons Rümker; Mare basaltic units Im1 and Em1 are combined into Em1; and Em2 is more likely the extending of Im2. Each of the previous proposed landing sites and their scientific value are summarized and reevaluated. Based on this, four landing sites are recommended in order to maximize the scientific outcome of the CE-5 mission. We suggest that the Eratosthenian-aged Em4 and Em1 units as the top priority landing site for the CE-5 mission; the age-dating results will provide important clues concerning the thermal evolution of the Moon.