Although the round surge structure is a deep structure, there are still extensive topographic and geological signs in the shallow crust due to long-term continuous activities. These penetrating and long-lived tectonic activities are sometimes strong and obvious, and sometimes weak and obscure, especially in Quaternary sedimentary areas and underwater areas, which are often easily overlooked because they are difficult to detect. These concealed or weakly displayed landforms and Quaternary geological signs are very important. There are many types of information and signs used to reveal and discover the annular structure, which are highly reliable, enlightening and sensitive, especially in the Quaternary coverage area and underwater area, which are often areas with concentrated human settlements, developed social economy, intensive engineering activities and complex environmental geology and geological disasters. In the past, the study of these areas was relatively low, but in fact, the geological study of these areas often has more important theoretical and practical value (Figure 2-32; The license plates are 5-5, 10-7, 17-2,17-13,28-113/kloc.

Figure 2-32 Geological and Geomorphological Signs of Circular Chung Structure

1. Topographic signs

Geomorphological structure, especially the combination of micro-geomorphological landscapes, has a unique and sensitive role in revealing the penetrating and long-lived annular structure, and these features are very detailed in remote sensing images and have wide development value.

(1) Normal landform types include hills, highlands, mountain knots, craters, submarine platforms, pingdingshan, islands with circular boundaries, rocks and volcanoes, circular cliffs, slopes and fracture zones. Such as Pamir Mountain Knot and Chayu Mountain Knot.

(2) Negative landform types, such as fault depression, basin, trough, depression, dished lowlands, lakes and swamps. , limited by circular faults. The torsion of double upwelling can form corresponding contemporaneous uplift and fault depression.

(3) Crater is a ring-shaped structure that is ubiquitous in the earth and earth-like stars. It generally consists of continuous surrounding ridges and depressions with a depression or highland in the middle. The simplex crater is controlled by the annular surge structure, which is composed of steep cliffs, mountain chains, ridges and slopes consistent with the main edge faults, and sometimes there are several parallel ridges and fault troughs. Because of the adjacent associated structural roots, there are two or more nested composite craters, and the central mountains and depressions are intertwined.

(4) Annular low-hilly depressions: In areas with weak neotectonic activity, the surface presents small annular low-lying depressions.

(5) Centripetal radial water system: deep circular swells often form surface subsidence, which leads to the convergence of water system to the central depression, forming a centripetal water system pattern.

(6) Radiant water system: The uplift of the deep annular surge structure makes the water system flow to the periphery, forming a radial ditch water system that deviates from the center.

(7) Annular water system: whether it is centripetal or centrifugal radial water system, the secondary water system develops along concentric fault zones, forming an obvious annular water system.

(8) Annular twisted section in regional water network: annular meandering section, annular gathering of rivers, lakes and swamps (such as Zoige area), annular twisted field, circuitous deformation (such as Taizhaozong Yuanyong structural block of Yarlung Zangbo River), etc.

(9) Annular lake swamp, annular zonal groundwater seepage, spring dew point, abnormal zone of surface soil moisture.

(10) Estuary-coast circular land-water two-span landform unit, circular estuary delta, underwater accumulation area.

(1 1) annular bottom pyrolysis zone of ice sheet and frozen zone. Such as Antarctic water cover, Siberia, Canada and other regions.

2. Quaternary geological indicators

(1) Circular fault sedimentary column and deep basin (including submarine lakes, deep sedimentary pits and pools).

(2) Building new round molasses in groups, strings and belts. Including explosive breccia accumulation, strong blasting rock area, collapse, mixed accumulation, debris flow, large-scale earthquake rupture and blasting, landslide accumulation. In the past, many mixed deposits formed by rock surges were wrongly classified as gravity deposits or turbidite deposits, including turbidite deposits and storm surge deposits near shallow seabed.

(3) Cenozoic volcanic eruption, lava flow and pyroclastic accumulation.

(4) Annular sedimentary and denudation zones with great thickness differences, and annular erosion/accumulation zones.

(5) The Quaternary formed by the strong explosion surge structure is a mixed accumulation zone mixed with a large number of in-situ old rocks.

(6) Annular Quaternary accumulation hydrothermal alteration, deep source gas-forming group zoning.

(7) Strong Quaternary ecological catastrophe zone. An ancient civilization area where a large number of creatures died, fossils were dense, explosive derivatives flourished and suddenly disappeared.

3. Signs of ecological disaster

(1) Abnormal distribution or variation of annular vegetation: abnormal distribution of vegetation density and types, death or extinction of a large number of populations, and prosperity of local populations.

(2) Annular abnormal drought, desertification and desertification. The local groundwater is abundant, flooded, swamped and salinized.

(3) Ancient strong earthquake, strong explosion of ancient land and the place where ancient civilization was annihilated.

(4) Areas with strong geogas, including gas-liquid discharge and geothermal anomalies (extreme heat, extreme cold, rainstorm, lightning, hurricane and drought, biological disasters).

(5) Round sections and plots that melt early and easily.

(6) Social disasters such as land, sea and air traffic disasters occur frequently.

4. Signs of neotectonic movement

The new tectonic movement is very common and easy to be detected, and it is often the resurrection of the ancient geological structure in the deep part of the earth. In order to explore the deep ring structure, various observation methods can be used to reveal and pursue it.

5. Modern geological structure clues

(1) Active faults and ground fissures: There are many forms of active faults at the top of deep circular structures, such as cliffs, structural depressions, low-lying areas, and the boundaries of arc-shaped ground uplift/subsidence areas. There are many non-deep reasons for the formation of new fault zones and ground fissures, such as the exploitation of groundwater, oil, natural gas and coal mines, and the uneven compaction of underground bedrock, which should be deleted and filtered in the analysis.

(2) Annular ground heave: Although there are many reasons for ground heave since Quaternary, most of them are caused by deep structures, especially the deep source differential heave movement unrelated to regional and regional shallow structures, which can be detected by repeated measurement of topographic deformation.

(3) Gravity collapse, rock creep and block sliding of large-scale and ultra-large-scale groups on the surface often have deep tectonic dynamic background of rock tides, such as giant rock sliding in the Hindu Kush-West oil landslide zone on the south side of the Himalayas, Jiuhua Mountain in Miyun, Beijing, Shandan, Gansu (the volume exceeds 1 000× 1 000× 200m3).

(4) Rock burst: Rock burst occurs not only in mine roadway, but also on the surface. The fracture of buildings, roads and pipelines on the ground and the sudden subsidence of the ground in a large area are often manifested as the violent impact of deep rock tides.

6. Remote sensing, geophysical and geochemical markers

(1) The remote sensing image shows: round color lump, cloud-like ring, and abnormal area of circular image structure; Circular, arc-banded, radial, turbine-shaped, dense cluster-shaped, bundle-shaped linear anomalies; Infrared thermal anomaly or negative thermal anomaly; Multi-band combination processing ring and displacement ring anomalies; Abnormal radar images, etc. There are many kinds and quantities of remote sensing information, which can be combined in multi-band, multi-temporal and multi-angle, showing the characteristics of many kinds and high sensitivity. At present, remote sensing is the only important means to reveal the deep structure of the earth's crust simply and sensitively before geophysical and geochemical exploration and drilling can detect the deep structure of the earth's crust, and it should be the main way to explore the deep structure.

(2) Annular gravity positive anomaly (high gravity), negative anomaly (low gravity) and annular gravity gradient zone. Annular magnetic anomalies include positive magnetic anomalies, negative magnetic anomalies and arc magnetic gradient zones. Circular rock mass shape, low speed and high conductivity block obtained by deep geophysical exploration, seismic exploration and magnetotelluric sounding. Geothermal exploration is an important means to find deep rock mass. In recent years, regional deep structural geophysical profiles, oil and gas exploration and marine geophysical exploration have provided a lot of data for revealing deep structures, but geological interpretation is still bound by the old structural concept.

(3) Annular and arc geochemical anomaly profiles: including the rising or abnormally low values of individual elements and groups of elements found on the ground, in water and in boreholes. The content of highly active halogen elements in various gases such as mercury, radon and argon is abnormal. These data can be obtained from regional geochemical exploration or special geochemical exploration, and if necessary, the geochemical exploration of deep rock surges and round surges can be specially designed.

7. Analyze the deep annular surge structure from the existing geological map.

At present, there are regional geological maps and geological maps of lots (mining areas) with different scales in all regions of the world. Although these geological maps have different levels of detail, the level of geological theory is high or low, and some of them are also influenced by the viewpoint of geological structure theory, which may not truly, comprehensively and vividly reflect the geological structure of the superficial part of the region, but after all, they describe a large number of geological structure characteristics. At first glance, it is a mess. After careful and in-depth analysis, we will analyze the deep structure hidden in it, especially the structural background of this round of skyrocketing.

Figure 2-33 Thickness Map of Basalt in Emei, Sichuan

According to my experiments in many places, the existing geological maps reflect some deep geological structure information to varying degrees. As long as they are analyzed and dialectical, many deep structural features can be sorted out, showing different types of ring structures. This method is effective in most cases, and it is a shortcut from shallow to deep.

(1) Circular and annular magmatic rocks or distributed annular magmatic rocks directly indicate the existence of upwelling geological environment and related geological events in the deep, regardless of their rock types. For example, Oman's semicircle ultrabasic rock-ophiolite suite itself is a part of the marginal zone of giant annular surge structure.

(2) Arc and annular fault zones, crushing zones, ductile shear zones, dikes and alteration zones, including radial and spiral linear geological elements. Although it is not necessarily complete, it will gradually become clear after referring to certain remote sensing image comparison and necessary recourse supplement, showing the deep round-surge structural background.

(3) Annular paleocrustal remains, crystalline basement, deep metamorphic area, late metamorphic annular halo (zone), color, color patches, speckles and cloud-like anomalies of annular remote sensing images.

(4) The lithofacies and thickness of the stratum are distributed in a ring shape, and structural changes may have taken place in the later period. With a little "reset" and "shaping", we can find the controlling effect of deep annular structure on caprock deposition.

(5) The distribution characteristics of Mesozoic and Cenozoic sediments are very sensitive to the display of deep annular structures. Most ring structures are consistent with Cenozoic activities. Neotectonic activities play a leading role in Mesozoic-Cenozoic sediments, including volcano-volcano deposits, and the formation of Mesozoic-Cenozoic basins and mountains. This development also reflects the advantages of deep ring structure. The spatial distribution characteristics of Mesozoic and Cenozoic basins and sediments can reflect many deep tectonic settings and thermal upwelling geological events.

(6) Analyze dome structure, annular basin and radial sliding block group from complex geological structure. For example, the Hindu Kush-West Varick belt on the southern margin of the Qinghai-Tibet Plateau and the Shandan landslide.

Figure 2-34 Geometrical model of the spatio-temporal evolution of the round surge structure system (including a small number of early residual round surge structures)