Method for predicting position of hydrothermal nozzle of jet flow sedimentary deposit
Technical Field
The invention belongs to the technical field of ore body prediction, and particularly relates to a method for predicting the position of a jet flow sedimentary deposit hydrothermal nozzle.
background
Since the discovery of low temperature subsea hot water jet sedimentary activity in the eastern pacific gallapagos expansion center in 1976, jet sedimentary rocks and deposits have become one of the most active research areas of the earth science.
At present, the prediction of the position of a hydrothermal vent on the seabed mainly comprises the steps of collecting samples and data of seawater or jet rocks around the vent, predicting the range of the hydrothermal vent through physical, geochemical and biological characteristic abnormalities, wherein the prediction method is mature; the physical characteristic prediction method mainly detects the range of the hydrothermal vent according to the magnetism and stress direction of ores, the viscosity of jet rocks, the temperature, salinity, density and transmittance of a water body, for example, Dissanayake and the like establish a comprehensive model of hydrodynamics, thermodynamics and deep sea hydrothermal vent minerals to predict the position of the east Pacific ocean front, and Chenkino and the like search the possible existing area of the hydrothermal vent by a horizontal maximum main stress low-value area caused by the self weight of the hydrothermal vent and the rock mass; the geochemical characteristic prediction method is mainly used for predicting the position of a hydrothermal jet port through the gas content, element composition and ion type in a water body, for example, Henrik et al researches the change of the gas content in hydrothermal jet rock and provides a qualitative prediction model of N-containing fluid after being sprayed out; the biological characteristic prediction method mainly judges the position of a hydrothermal nozzle through the enrichment degree of a hydrothermal biological community, and Zekely judges the position of the nozzle according to the fact that the hydrothermal biological community is abnormally enriched in the Atlantic ocean and the east Pacific ocean near the nozzle.
The method for predicting the position of the hydrothermal vent by researching biological fossil is still in an exploration stage, for example, the method for judging the hydrothermal vent by using the characteristics of the biological fossil in rock by Yangzedong and the like is simple and clear, but is difficult to popularize due to the influence of the content of the biological fossil, the biological activity range of the hydrothermal vent, the later geological activity improvement and the like, and still needs to be further improved.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a method for predicting the position of a hydrothermal vent of a jet flow deposition ore deposit, which can effectively avoid the influence of factors such as the content of biological fossil, the biological activity range of hydrothermal fluid, and the like, and correct the position of the hydrothermal vent through macroscopic indexes such as the thickness of ore body, the thickness of ore body and the structure in the ore deposit in each mineralization stage, and microscopic indexes such as the composition of minerals in the ore, so that the method has the advantages of integrity, high efficiency, controllability, uniformity, and the like, improves the situation of predicting the position of the hydrothermal vent by a single index, and has a good prediction effect.
meanwhile, the influence of factors such as later geological activity transformation can be reduced.
In order to solve the technical problems, the invention adopts the technical scheme that: a method of predicting the position of a jet deposit hydrothermal port, the method comprising the steps of:
step one, determining the mineralization period and the mineralization stage of an ore deposit;
Step two, determining the total thickness of the ore body and the thickness of the ore body in each mineralization stage determined in the step one by a method of drilling, slot probing and underground engineering field measurement in sequence;
Thirdly, modeling on a computer, and reducing the total thickness of the ore body and the thickness of the ore body in each mineralization stage;
Step four, coupling the total thickness of the ore body and the thickness of the ore body in each mineralization stage, and marking out an abnormal area;
Fifthly, preliminarily correcting the position of the hot liquid nozzle according to the structure in the ore deposit;
sixthly, correcting the position of the hot liquid nozzle again according to mineral composition in the ore;
and seventhly, predicting the position of the hot liquid nozzle.
in the method for predicting the position of the jet flow sedimentary deposit hydrothermal nozzle, in the step one, when the mineralization period of the deposit is determined, the mineralization period is divided according to the oxidation reduction degree, and the mineralization period is named by 1-3 mineral names or mineral types; when the mineralization stage is determined in the first step, the mineralization stage is divided into high temperature, medium temperature and low temperature according to the formation temperature of minerals, the ore bodies formed in the same temperature range belong to the same mineralization stage, and the mineralization stage is named by 1-3 mineral names or mineral types; wherein the high temperature is higher than 300 ℃, the medium temperature is between 200 ℃ and 300 ℃, and the low temperature is less than 200 ℃.
In the method for predicting the position of the hydrothermal vent of the jet sedimentary deposit, the modeling on the computer is performed by Auto CAD software or Arcgis software in step three.
The method for predicting the position of the jet flow sedimentary deposit hydrothermal nozzle is characterized in that: modeling on a computer in the third step, and drawing by taking 0.5m as an interval when the total thickness of the ore body and the thickness of the ore body in each mineralization stage are reduced and the total thickness of the ore body is within 15 m; when the total thickness of the ore body is 15-25 m, the thickness boundary of each mineralization stage is drawn by taking 0.8m as an interval; when the total thickness of the ore body is more than 25m, the thickness boundary of each mineralization stage is drawn by taking 1.0m as a distance; when the thickness of the ore at different mineralization stages is within 3m, drawing the thickness boundary of the ore by taking 0.10m as an interval; when the thickness of the ore at different mineralization stages is 3-6 m, drawing the thickness boundary of the ore by taking 0.20m as an interval; the ore thickness cut is plotted at 0.40m intervals when the thickness of the ore in different stages is outside 6 m.
In the method for predicting the position of the hot liquid nozzle of the jet flow deposition deposit, the total thickness of the ore body and the thickness of the ore body in each mineralization stage are coupled in step four, and the specific method for marking out the abnormal area comprises the following steps: carrying out superposition coupling on the total thickness of ore bodies in the ore deposit and the thickness of the ore bodies in each mineralization stage, wherein in the coupling process, an area with the thickness variation coefficient of the ore bodies being more than 0.2 is an abnormal area of the ore body thickness, and when the thickness of the ore bodies in 1 or 2 mineralization stages is abnormal, judging the abnormal area as a false abnormal area; and when the thickness of the ore body is abnormal in more than 3 mineralization stages, judging the abnormal area as a suspected true abnormal area.
in the method for predicting the position of the hydrothermal vent of the jet flow sedimentary deposit, the step five of primarily correcting the position of the hydrothermal vent according to the structure in the deposit comprises the following specific processes:
Step 501, judging according to the distance between the abnormal area and the fault, and when the distance between the suspected true abnormal area and the nearest fault exceeds 100m, judging the suspected true abnormal area as a false abnormal area; otherwise, when the distance between the suspected true abnormal area and the nearest fault is less than or equal to 100m, the suspected true abnormal area is also judged as the suspected true abnormal area, and step 502 is executed;
Step 502, judging according to the shape of the abnormal area, when the thickness of the ore body in the suspected true abnormal area is rapidly thickened near the fault and then slowly thickened, and the long axis of the ore body in the suspected abnormal area is parallel to the fault, further judging the suspected true abnormal area as the suspected true abnormal area, and executing step six, when the thickness of the ore body in the suspected true abnormal area is not changed near the fault, judging the suspected true abnormal area as the false abnormal area.
in the method for predicting the position of the hydrothermal vent of the spouted sedimentary deposit, the concrete process of correcting the position of the hydrothermal vent again according to the mineral composition in the ore in the sixth step is as follows:
601, judging according to an ideal distribution state of minerals in an ore body of an abnormal area, and when the minerals in a suspected true abnormal area are sequentially distributed according to the sequence of high-temperature minerals, medium-temperature minerals and low-temperature minerals, judging the suspected true abnormal area as a true abnormal area; when the minerals in the suspected true abnormal area are not distributed in sequence according to the sequence of the high-temperature minerals, the medium-temperature minerals and the low-temperature minerals, the suspected true abnormal area is judged as the suspected true abnormal area, and step 602 is executed;
step 602, according to the judgment of the mineral content in the ore body of the abnormal area, when the mineral content in the suspected true abnormal area meets two of three conditions of 50% of medium-temperature mineral content and 50% of low-temperature mineral content, 30% of medium-temperature mineral content and 70% of low-temperature mineral content, and 100% of low-temperature mineral content, the suspected true abnormal area is judged as a true abnormal area, otherwise, when the mineral content in the suspected true abnormal area does not meet two of three conditions of 50% of medium-temperature mineral content and 50% of low-temperature mineral content, 30% of medium-temperature mineral content, 70% of low-temperature mineral content, and 100% of low-temperature mineral content, the suspected true abnormal area is judged as a false abnormal area.
In the method for predicting the position of the hydrothermal vent of the spouted sedimentary deposit, in the seventh step, the specific method for predicting the position of the hydrothermal vent is as follows: when the ore bodies in the abnormal area are not completely parallel near the fault and the ore bodies in the abnormal area are convex, the convex positions of the ore bodies are connected, and the junction of the connecting line and the fault is the hot liquid nozzle position.
compared with the prior art, the invention has the following advantages:
1. According to the method, the total thickness of the ore body and the thickness of the ore body in each mineralization stage are coupled, so that the influence of factors such as the content of biological fossil and the biological activity range of hydrothermal solution can be effectively avoided in the process of predicting the position of the hydrothermal solution nozzle, and meanwhile, the influence of factors such as later geological activity modification can be reduced.
2. The hydrothermal nozzle position prediction method based on the macro-index ore body thickness, the ore body thickness and the structure in the ore deposit at each mineralization stage and the micro-index mineral composition in the ore has the advantages of integrity, high efficiency, controllability, uniformity and the like, and the condition that the hydrothermal nozzle position is predicted by a single index is improved.
3. The method disclosed by the invention is simple, easy to control and low in cost, can generate a good prediction effect, and has a high economic effect on deep ore body prediction.
In conclusion, in the process of predicting the position of the hydrothermal vent, the influence of factors such as the content of biological fossil, the biological activity range of hydrothermal and the like can be effectively avoided, and meanwhile, the influence of factors such as later geological activity improvement and the like can be reduced; the hydrothermal nozzle position prediction is carried out through macroscopic index ore body thickness, ore deposit structure and microscopic index mineral composition, the hydrothermal nozzle position prediction method has the advantages of integrity, high efficiency, controllability, uniformity and the like, the situation that the hydrothermal nozzle position is predicted through a single index is improved, and a good prediction effect can be generated.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
drawings
FIG. 1 is a block flow diagram of the method of the present invention;
FIG. 2 is a schematic diagram of the suspected true abnormal area extraction according to the present invention;
FIG. 3 is a schematic view of the present invention illustrating the initial correction of anomalous zones based on the formation within the deposit;
FIG. 4 is a schematic view of the present invention in which the abnormal region is again corrected according to the mineral composition in the ore;
FIG. 5 is a schematic view of a predicted area of a jet deposit hot liquid port location of the present invention.
Detailed Description
As shown in fig. 1, the method for predicting the position of a jet deposition deposit hydrothermal vent of the present invention comprises the following steps:
step one, determining the mineralization period and the mineralization stage of an ore deposit;
In the embodiment, when the mineralization period of the ore deposit is determined in the step one, the mineralization period is divided according to the oxidation reduction degree, and the mineralization period is named by 1-3 mineral names or mineral types; when the mineralization stage is determined in the first step, the mineralization stage is divided into high temperature, medium temperature and low temperature according to the formation temperature of minerals, the ore bodies formed in the same temperature range belong to the same mineralization stage, and the mineralization stage is named by 1-3 mineral names or mineral types; wherein the high temperature is higher than 300 ℃, the medium temperature is between 200 ℃ and 300 ℃, and the low temperature is less than 200 ℃.
in specific implementation, taking the barite deposit at the edge of the great river of Guizhou as an example, the deposit is divided into a quartz-sulfate stage and a sulfide stage according to the oxidation reduction degree, wherein the quartz-sulfate stage is divided into a quartz-silicate stage with the formation temperature between 200 ℃ and 300 ℃ and a sulfate stage with the formation temperature less than 200 ℃ according to the formation temperature of the mineral.
Step two, determining the total thickness of the ore body and the thickness of the ore body in each mineralization stage determined in the step one by a method of drilling, slot probing and underground engineering field measurement in sequence;
During specific implementation, field investigation is firstly carried out before drilling, drilling and logging are carried out after drilling, then groove detection is carried out, underground tunnel logging is carried out during underground engineering field measurement, then an electron microscope is combined for observing and carrying out detailed analysis on ore deposit, ore body and ore, the main mineralization stage of the ore deposit is taken as the key point for measurement, wherein the field geological investigation is used for mainly researching the form and the structure time of the ore body and the relation between the ore body, geological logging is carried out in sections with multiple ore types and structure development, according to the mode of combining the whole-roadway logging and the key-section fine logging of the ore body, the mode of combining macroscopic fine dissection research and microscopic fine dissection research is grasped, samples of all texture ores on a section are systematically collected, ores with different textures need to be sampled, the total number of the ores with the same texture on the same section is not less than 2, and profile control, small-density coverage, proper amount, and the like, Emphasis on the characteristic points, and the like.
thirdly, modeling on a computer, and reducing the total thickness of the ore body and the thickness of the ore body in each mineralization stage;
In this embodiment, the modeling on the computer in step three is performed by Auto CAD software or Arcgis software.
In this embodiment, in the third step, when modeling is performed on the computer to reduce the total thickness of the ore body and the thickness of the ore body in each mineralization stage, and when the total thickness of the ore body is within 15m, the thickness boundary of each mineralization stage is drawn at an interval of 0.5 m; when the total thickness of the ore body is 15-25 m, the thickness boundary of each mineralization stage is drawn by taking 0.8m as an interval; when the total thickness of the ore body is more than 25m, the thickness boundary of each mineralization stage is drawn by taking 1.0m as a distance; when the thickness of the ore at different mineralization stages is within 3m, drawing the thickness boundary of the ore by taking 0.10m as an interval; when the thickness of the ore at different mineralization stages is 3-6 m, drawing the thickness boundary of the ore by taking 0.20m as an interval; the ore thickness cut is plotted at 0.40m intervals when the thickness of the ore in different stages is outside 6 m.
step four, coupling the total thickness of the ore body and the thickness of the ore body in each mineralization stage, and marking out an abnormal area;
In this embodiment, the prediction of the hot liquid nozzle position is performed through the macroscopic index ore body thickness and the ore body thickness in each mineralization stage, and the specific method for dividing the abnormal area by coupling the total ore body thickness and the ore body thickness in each mineralization stage in the fourth step is as follows: performing superposition coupling on the total thickness of ore bodies in the ore deposit and the thickness of the ore bodies in each mineralization stage, judging an area with the thickness variation coefficient of more than 0.2 of the ore bodies as a thickness abnormal area in the coupling process, and judging the abnormal area as a false abnormal area when the thickness of the ore bodies in 1 or 2 mineralization stages is abnormal; and when the thickness of the ore body is abnormal in more than 3 mineralization stages, judging the abnormal area as a suspected true abnormal area.
in specific implementation, the total thickness of the ores in the main mineralization stage and the thickness of the ore body in each mineralization stage are coupled to be taken as key research objects for superposition coupling.
for example, as shown in fig. 2, a suspected true abnormal area 1, a suspected true abnormal area 2 and a suspected true abnormal area 3 are determined by superposing and coupling the total thickness of the ore body and the thickness of the ore body in each mineralization stage.
Fifthly, preliminarily correcting the position of the hot liquid nozzle according to the structure in the ore deposit;
In this embodiment, the hydrothermal vent position is predicted by using a macro index in-deposit structure, and the specific process of primarily correcting the hydrothermal vent position according to the in-deposit structure in the fifth step is as follows:
Step 501, judging according to the distance between the abnormal area and the fault, and when the distance between the suspected true abnormal area and the nearest fault exceeds 100m, judging the suspected true abnormal area as a false abnormal area; otherwise, when the distance between the suspected true abnormal area and the nearest fault is less than or equal to 100m, the suspected true abnormal area is also judged as the suspected true abnormal area, and step 502 is executed;
Step 502, judging according to the shape of the abnormal area, when the thickness of the ore body of the suspected true abnormal area is rapidly thickened near the fault and then slowly thickened, and the long axis of the ore body of the suspected abnormal area is parallel to the fault, further judging the suspected true abnormal area as the suspected true abnormal area, and executing step six, when the thickness of the ore body of the suspected true abnormal area is not changed near the fault, judging the suspected true abnormal area as the false abnormal area.
as shown in fig. 3, the suspected true abnormal area 2 in fig. 2 is determined as a false abnormal area by the correction method in step 502, the suspected true abnormal area 3 in fig. 2 is determined as a false abnormal area by the correction method in step 501, and the suspected true abnormal area 2 and the suspected true abnormal area 3 are directly excluded.
sixthly, correcting the position of the hot liquid nozzle again according to mineral composition in the ore;
In this embodiment, the hydrothermal vent position is predicted by microscopic index of mineral composition in the ore, and the specific process of re-correcting the hydrothermal vent position according to mineral composition in the ore in the sixth step is as follows:
601, judging according to an ideal distribution state of an ore body in an abnormal area, and when minerals in a suspected true abnormal area are sequentially distributed according to the sequence of high-temperature minerals, medium-temperature minerals and low-temperature minerals, judging the suspected true abnormal area as a true abnormal area; when the minerals in the suspected true abnormal area are not distributed in sequence according to the sequence of the high-temperature minerals, the medium-temperature minerals and the low-temperature minerals, the suspected true abnormal area is judged as the suspected true abnormal area, and step 602 is executed;
Step 602, judging according to the mineral content in the ore body of the abnormal area, when the mineral content in the suspected true abnormal area meets two of three conditions of 50% of medium-temperature mineral content and 50% of low-temperature mineral content, 30% of medium-temperature mineral content and 70% of low-temperature mineral content, and 100% of low-temperature mineral content, judging the suspected true abnormal area as a true abnormal area, otherwise, when the mineral content in the suspected true abnormal area does not meet two of three conditions of 50% of medium-temperature mineral content and 50% of low-temperature mineral content, 30% of medium-temperature mineral content, 70% of low-temperature mineral content, and 100% of low-temperature mineral, judging the suspected true abnormal area as a false abnormal area;
as shown in fig. 4, the suspected true abnormal area meeting step five is corrected in step six, and the suspected true abnormal area 1 is determined to be a true abnormal area by observing the distribution sequence of minerals in the ore body of the suspected true abnormal area.
In this embodiment, the true abnormal area is further determined by determining the change law of the mineral composition and the mineral morphology (i.e. whether the distribution of the ore in the ore body is distributed in the order of high temperature, medium temperature and low temperature).
And seventhly, predicting the position of the hot liquid nozzle.
in this embodiment, the specific method for predicting the position of the hot liquid nozzle in the seventh step is as follows: when the ore bodies in the abnormal area are not completely parallel near the fault and the ore bodies in the abnormal area are convex, the convex positions of the ore bodies are connected, and the junction of the connecting line and the fault is the hot liquid nozzle position.
As shown in fig. 5, F1 is a fault, and the junction between the extension line connecting the protruding positions of the ore bodies and the fault is a hot liquid spout position.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.