Geological and geophysical interpretation of the detailed geophysical data on the Lower Zeya region of the Zeya-Bureya sedimentary basin

This paper presents new land and underwater gravity data for the southern portion of the Avalon Terrane of Newfoundland. These gravity data are combined with existing airborne and marine magnetic data to produce a detailed geophysical interpretation of the geology of the southern Avalon Peninsula and the adjacent portions of Placentia and St. Mary's bays.Qualitative interpretation of the geophysical data in conjunction with the known geology reveals that the major faults previously mapped only on land and inferred beneath St. Mary's Bay can be traced offshore geophysically. In addition, the previously unknown offshore limits of a small sedimentary basin in the southeast part of the area can be delineated.Quantitative modelling demonstrates that (1) Precambrian mafic to ultramafic rocks underlie the whole area, (2) thrust faulting in the St. Mary's Peninsula and elsewhere has led to the juxtaposition of Bull Arm volcanic rocks over Harbour Main volcanic rocks, and (3) the evolution of the area may be explained by a combination of earlier volcanic island and extensional models.The mapping has also revealed the presence of previously unknown northwest–southeast lineations in the geophysical patterns, which may be related to the late wrench faulting.

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Gold-Bearing Brown Coal Deposits of the Zeya–Bureya Sedimentary Basin (East Russia): Fundamental Model of Formation

Minerals ◽

10.3390/min11070682 ◽

2021 ◽

Vol 11 (7) ◽

pp. 682

Author(s):

Anatoliy Petrovich Sorokin ◽

Andrey Alexeyevich Konyushok ◽

Valeriy Mikhailovich Kuz’minykh ◽

Sergey Vadimovich Dugin

Keyword(s):

Sedimentary Basin ◽

Complex Compounds ◽

Inorganic Materials ◽

Primary Sources ◽

East Russia ◽

High Concentrations ◽

Geochemical Analyses ◽

Element Transfer ◽

Bureya Sedimentary Basin ◽

Gold Bearing

The primary sources and the conditions for the formation of the Paleogene–Neogene coal-bearing deposits in the Zeya–Bureya sedimentary basin were identified and studied with the help of paleogeographic reconstructions and geochemical analyses. Based on the results obtained, we suggest a new basic model of element transfer into the coal, involving two mutually complementary processes to account for the introduction and concentration of gold and other trace elements in the sequences investigated. The first process reflects the system in which peatlands were concentrated along the basin’s junction zone and the passive internal residual mountain ranges. The second reflects the junction’s contrast-type (sharp-type) forms conditions along the external mobile mountain-fold frame. The eroded gold particles were transported over 10–20 km as complex compounds, colloids, dispersed particles, and nanoparticles, and remobilized into clastogenic and dissolved forms along the first few kilometers. The release of gold in the primary sources occurred due to weathering of gold-bearing ore zones, followed by transportation of gold by minor rivers to the areas of peat accumulation. This study considered the probability of the accumulation of high concentrations of gold and rare earth elements (REE) in coal due to the introduction of organic and inorganic materials during floods, with episodes of catastrophic events, and volcano–hydrothermal activities.

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Multiphysics anomaly map: A new data fusion workflow for geophysical interpretation

Interpretation ◽

10.1190/int-2018-0178.1 ◽

2020 ◽

Vol 8 (2) ◽

pp. B35-B43

Author(s):

Julio Cesar S. O. Lyrio ◽

Paulo T. L. Menezes ◽

Jorlivan L. Correa ◽

Adriano R. Viana

Keyword(s):

Data Fusion ◽

Geophysical Methods ◽

Real Data ◽

Logistic Function ◽

Geophysical Data ◽

Data Set ◽

Geophysical Interpretation ◽

Wide Range ◽

Anomaly Map ◽

Different Response

When collecting and processing geophysical data for exploration, the same geologic feature can generate a different response for each rock property being targeted. Typically, the units of these responses may differ by several orders of magnitude; therefore, the combination of geophysical data in integrated interpretation is not a straightforward process and cannot be performed by visual inspection only. The multiphysics anomaly map (MAM) that we have developed is a data fusion solution that consists of a spatial representation of the correlation between anomalies detected with different geophysical methods. In the MAM, we mathematically process geophysical data such as seismic attributes, gravity, magnetic, and resistivity before combining them in a single map. In each data set, anomalous regions of interest, which are problem-dependent, are selected by the interpreter. Selected anomalies are highlighted through the use of a logistic function, which is specially designed to clip large magnitudes and rescale the range of values, increasing the discrimination of anomalies. The resulting anomalies, named logistic anomalies, represent regions of large probabilities of target occurrence. This new solution highlights areas where individual interpretations of different geophysical methods correlate, increasing the confidence in the interpretation. We determine the effectiveness of our MAM with application to real data from onshore and offshore Brazil. In the onshore Recôncavo Basin, the MAM allows the interpreter to identify a channel where a drilled well found the largest sandstone thickness on the area. In a second example, from offshore Sergipe-Alagoas Basin, the MAM helps differentiate between a dry and an oil-bearing channel previously outlined in seismic data. Therefore, these outcomes indicate that the MAM is a valid interpretation tool that we believe can be applied to a wide range of geologic problems.

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A geophysical interpretation of the geology of Conception Bay, Newfoundland

Canadian Journal of Earth Sciences ◽

10.1139/e83-128 ◽

1983 ◽

Vol 20 (9) ◽

pp. 1421-1433 ◽

Cited By ~ 5

Author(s):

H. G. Miller

Keyword(s):

Magnetic Susceptibility ◽

Volcanic Rocks ◽

Magnetic Anomalies ◽

Vertical Movement ◽

Geophysical Data ◽

Two Dimensional ◽

Geophysical Interpretation ◽

Gravity And Magnetic ◽

Conception Bay ◽

Avalon Peninsula

Geophysical data from Conception Bay and the adjacent peninsulas of the Avalon Peninsula, Newfoundland are presented and quantitatively interpreted using two-dimensional models to interpret the geology beneath the bay. The portion of the bay underlain by mafic volcanic rocks is determined and the maximum extent of the Cambro-Ordovician rocks containing the Wabana hematite deposit is delineated. All gravity and magnetic anomalies in the area are explained in terms of density and magnetic susceptibility variations confined to the upper 12 km of the crust. The geophysical models indicate that mafic volcanics underlie a significant portion of the study area and are more extensive than indicated by the surface outcrop on land. The models also indicate significant vertical movement on the Topsail Fault and on the extension of a fault passing out into the bay near Holyrood. The Cambro-Ordovician sediments are confined to the southern portion of the block bounded by these faults. The geophysical data are unable to detect the presence of the mafic volcanics east of the Topsail Fault in the study area.

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Distribution of Cenozoic metalliferous coal deposits in Zeya-Bureya Sedimentary Basin (Eastern Siberia): Tectonic reconstruction and paleogeographic analysis

Геотектоника ◽

10.31857/s0016-853x2019233-45 ◽

2019 ◽

pp. 33-45 ◽

Cited By ~ 1

Author(s):

A. P. Sorokin ◽

A. A. Konyushok ◽

V. M. Kuzminykh ◽

T. V. Artyomenko ◽

A. A. Popov

Keyword(s):

Noble Metals ◽

Middle Miocene ◽

Sedimentary Basin ◽

Bureya Basin ◽

Coal Deposits ◽

Tectonic Reconstruction ◽

Basin Formation ◽

High Level ◽

Bureya Sedimentary Basin ◽

Geodynamic Activity

Distribution of noble metals, rare metals and rare earth elements in the Paleocene and Lower-Middle Miocene coals of Zeya-Bureya sedimentary basin was analyzed. Reconstruction of the basin formation in the Mesozoic and Cenozoic was performed with detailed paleogeographic analysis of the Cenozoic coal-bearing sequences from the position of geodynamic features of the adjacent regions development. Geological events at the turn of the Cretaceous and Paleogene are considered. Comprehensive analysis of the metal content in the basin frame carried out. We described conditions of migration and localization of trace elements. Given conditions arose mainly in the process of geodynamics developed on the northwestern flank of the Zeya-Bureya basin including the static orogens in the Paleocene — Miocene where the sedimentation was actively expanding. Microelements migration with capturing denudation plains occurred in stable processes of peat accumulation and localization of economically important components in streams associated with plains. Contrasting forms of conjugation in the flexure-uplift system and uneven localization of microelements are determined by high level of geodynamic activity on the south-eastern margin of Zeya-Bureya sedimentary basin. The presence of gold throughout the strata of the Paleocene and Lower-Middle Miocen coal-bearing sediments in the Sergeevskoe, Yerkovetskoe and Raychikhinskoe deposits is established. The Sergeevskoe deposit coals are enriched with Be, Sc, V, Ga, Rb, Nb, Ta, REE + Y.

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On: “THE RELATIVE PLACE OF EMPIRICAL AND ANALYTICAL METHODS OF GEOPHYSICAL INTERPRETATION”

Geophysics ◽

10.1190/1.1486511 ◽

1942 ◽

Vol 7 (3) ◽

pp. 291-292

Author(s):

R. Clare Coffin

Keyword(s):

Analytical Method ◽

Analytical Methods ◽

Analytical Procedure ◽

Empirical Method ◽

Empirical Approach ◽

Geophysical Data ◽

Geophysical Exploration ◽

Empirical Procedure ◽

Geophysical Interpretation

I agree with Mr. Weaver in the relative merits of an analytical procedure as opposed to an empirical procedure in the analysis of geophysical data. However, the pioneer in geophysical exploration in entirely unexplored areas may be obliged to resort to the empirical approach to his data. This he may do sometimes to his advantage, but his errors come in applying the method over too large a territory. Certainly, he should use the empirical method with caution and abandon it in favor of the analytical method when data are available for such procedure.

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Geology differentiation: A new frontier in quantitative geophysical interpretation in mineral exploration

The Leading Edge ◽

10.1190/tle38010060.1 ◽

2019 ◽

Vol 38 (1) ◽

pp. 60-66 ◽

Cited By ~ 11

Author(s):

Yaoguo Li ◽

Aline Melo ◽

Cericia Martinez ◽

Jiajia Sun

Keyword(s):

Mineral Exploration ◽

Physical Property ◽

Step Change ◽

Geophysical Data ◽

Historical Background ◽

Data Sets ◽

Geologic Structure ◽

Geophysical Interpretation ◽

New Frontier ◽

Quantitative Approaches

Geophysics aims to image subsurface geologic structure and identify different geologic units. While the former has dominated the interpretation of applied geophysical data, the latter has received much less attention. This appears to have persisted despite applications such as those in mineral exploration that inherently rely on the inference of geologic units from geophysical and geologic observations. In practice, such activities are routinely carried out in a qualitative manner. Thus, it is meaningful to examine this aspect and to develop a system of quantitative approaches to identify different geologic units. The development of geophysical inversions in the last three decades makes such interpretation tools possible. We refer to this newly emerging direction as geology differentiation and the resultant representation of geology model as a quasi-geology model. In this article, we will provide an overview of the historical background of geology differentiation and the current developments based on physical property inversions of geophysical data sets. We argue that integrating multiple physical property models to differentiate and characterize geologic units and work with the derived quasi-geology model may lead to a step change in maximizing the value of geophysical inversions.

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Mesozoic sandstones and the reconstruction of tectonic depositional environments in the Bureya sedimentary basin in the Far East

Russian Journal of Pacific Geology ◽

10.1134/s1819714014040058 ◽

2014 ◽

Vol 8 (4) ◽

pp. 300-314 ◽

Cited By ~ 1

Author(s):

S. A. Medvedeva

Keyword(s):

Sedimentary Basin ◽

Far East ◽

Depositional Environments ◽

The Far East ◽

Bureya Sedimentary Basin

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The northwest portion of the Gander Zone — a geophysical interpretation

Canadian Journal of Earth Sciences ◽

10.1139/e82-119 ◽

1982 ◽

Vol 19 (7) ◽

pp. 1371-1381 ◽

Cited By ~ 3

Author(s):

H. G. Miller ◽

H. C. Weir

Keyword(s):

Crustal Structure ◽

Geophysical Data ◽

Crustal Material ◽

Continental Rise ◽

Iapetus Ocean ◽

Geophysical Interpretation ◽

Geological Models

Geophysical data from the northwestern portion of the Gander Zone of Newfoundland are used to test existing geological models and to propose amended ones for the upper crustal structure of the region. The eastern geophysical boundary of in situ Paleozoic oceanic crustal material associated with the Iapetus Ocean is interpreted to be the GRUB line. An enigmatic anomaly belt in the Gander Group east of the GRUB line is identified and modelled. Three hypotheses are advanced for its origin, none of which can be eliminated on simple geophysical grounds. This anomaly belt is interpreted to present obducted ophiolitic materials emplaced in the continental rise prism represented by the Gander Group sediments.

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On: “THE RELATIVE PLACE OF EMPIRICAL AND ANALYTICAL METHODS OF GEOPHYSICAL INTERPRETATION”

Geophysics ◽

10.1190/1.1486508 ◽

1942 ◽

Vol 7 (3) ◽

pp. 290-291

Author(s):

Frank Goldstone

Keyword(s):

Scientific Knowledge ◽

Analytical Methods ◽

Applied Science ◽

Geophysical Data ◽

Herbal Remedies ◽

Geophysical Interpretation ◽

Evil Spirits ◽

The Witch

Mr. Weaver’s paper is a challenge to analyze our present methods of turning geophysical data into drill sites and to question whether these methods make full use of scientific knowledge. The development of most applied science has been from the empirical to the analytic. To take medicine as an example; primitive peoples had an equal faith in their witch doctors as in their herbal remedies. It required the skilled observation of the scientist to prove that the witch doctor’s dance was less curative than the quinine, and yet 400 years after Hippocrates civilized peoples were still casting out evil spirits from the sick. When and how did exploration geophysicists graduate from the necromantic era and did we leave too many Hippocrates’ unheeded?

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