The geology of Denmark includes 12 kilometers of unmetamorphosed sediments lying atop the Precambrian Fennoscandian Shield, the Norwegian-Scottish Caledonides and buried North German-Polish Caledonides. The stable Fennoscandian Shield formed from 1.45 billion years ago to 850 million years ago in the Proterozoic. The Fennoscandian Border Zone is a large fault, bounding the deep basement rock of the Danish Basin—a trough between the Border Zone and the Ringkobing-Fyn High. The Sorgenfrei-Tornquist Zone is a fault-bounded area displaying Cretaceous-Cenozoic inversion. [1]
Cambrian rocks record successive marine transgression and regression events. Feldspar-rich red bed sandstones deposited in windy floodplains followed by layers of glauconite-rich marine sandstones and offshore siltstone. Black alum shales deposited in the mid-Cambrian in a nearly anoxic epeiric basin with limestone layers, rich in trilobite fossils. Condensed, shallow limestone succeeded the black shales in the Ordovician, with numerous graptolite fossils.
Devonian rocks have never been found in Denmark and marine Carboniferous rocks are only known from drill holes at the southern edge of the Ringkobing-Fyn High, which formed at the time as a bulging area north of the Variscan collision zone.
Rotational block faulting in the Late Carboniferous resulted from Variscan wrench deformation, active along the Sorgenfrei-Tornquist Zone. Syn-rift clastic wedges began to accumulate in an emerging half-graben. Continental red beds were deposited and volcanism occurred.
Regional sagging began in the mid-Permian, leaving the Ringkobing-Fyn High as a high point. Marine transgression began, connecting the region with a narrow seaway to the Shetland Islands. The Danish Basin and the neighboring North German Basin were both highly saline and brackish, leaving behind carbonate and anhydrite layers on the southern edge of the High. Up to 1.2 kilometers of halite accumulated in the North Permian Basin, thinning toward the Fennoscandian Border Zone. Subsequent salt tectonism has produced salt diapirs 10 kilometers in diameter, rising five kilometers through overhead rock and some are less than 200 meters deep in Quaternary rocks. [2]
North-south rifting with the breakup of Pangea in the Triassic segmented the Ringkobing-Fyn High into a narrow graben. Sedimentation occurred in fault-bounded alluvial fan deposits with occasional small marine transgressions, such as the Muschekalk Sea in the mid-Triassic in the Ringkobing-Fyn High. Triassic outcrops are only found on southern shore of Bornholm. Extensional faulting occurred throughout the Mesozoic, but overall, conditions remained the same into the Cretaceous. Oscillating marine transgressions in the Rhaetian to Middle Jurassic shifted deposition from delta sands to offshore mudstones and regional updoming took place at the junction of the Central Graben, Moray Firth and Viking Graben. Deltas were drowned and replaced with deepwater basins. Major rifting in the Late Jurassic produced block tilting.
Sedimentation shifted in Albian through Danian times from siliclastic to carbonaceous, marked by marl and glauconite sandstones. Sea level fell in the Maastrichtian, restricting the sea to deeper areas of the Central Graben. The Stevns Klint type locality contains the Fish Clay with an iridium anomaly indicative of the K-Pg mass extinction. [3]
During the Danian Stage, carbonate deposition stopped, resulting in an erosional unconformity. As the Selandian transgressive phase got underway, glauconite sand and older, reworked Cretaceous and Devonian sediments were deposited, overlain by pelagic smectite clay. Erosion in the Neogene and Pleistocene has eroded most rock units that would likely have indicated open marine conditions. A break in sedimentation in the Oligocene was followed by a marine transgression and sediment accumulated in the Danish Basin, with significant coarse quartz sand compared to older Paleogene clays.
The deepest point of deposition—the depocenter—moved toward the North Sea and Central Graben during the Oligocene and the coastline shifted to the Fennoscandian Border Zone in Jylland. This was a result of regional uplift of the Norwegian Caledonides and the Fennoscandian Shield. The Caledonides were eroded to a nearly flat peneplain by the Permian and so the uplift was non-orogenic and comparatively recent. Shallow marine deposition continued until the Pleistocene with increasing sand and coal from the Miocene. Up to three kilometers of sand accumulated in the Central Graben.
During the Pleistocene, the region was glaciated multiple times, leaving glaciofluvial plains in the west and clay soils in the east. Isostatic rebound and post-glacial thin-skinned folding and thrusting have been common geologic forces in the Holocene. [4]
Denmark has few natural resources although some small oil and gas fields have been found offshore since the 1970s. Gravel, sand, and chalk are all mined for building material and in North Jylland, plastic clay and diatomite are extracted as insulation material. [5]
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The geology of Georgia is the study of rocks, minerals, water, landforms and geologic history in Georgia. The country is dominated by the Caucasus Mountains at the junction of the Eurasian Plate and the Afro-Arabian Plate, and rock units from the Mesozoic and Cenozoic are particularly prevalent. For much of its geologic history, until the uplift of the Caucasus, Georgia was submerged by marine transgression events. Geologic research for 150 years by Georgian and Russian geologists has shed significant light on the region and since the 1970s has been augmented with the understanding of plate tectonics.
The geology of Bosnia & Herzegovina is the study of rocks, minerals, water, landforms and geologic history in the country. The oldest rocks exposed at or near the surface date to the Paleozoic and the Precambrian geologic history of the region remains poorly understood. Complex assemblages of flysch, ophiolite, mélange and igneous plutons together with thick sedimentary units are a defining characteristic of the Dinaric Alps, also known as the Dinaride Mountains, which dominate much of the country's landscape.
The geology of Ukraine is the regional study of rocks, minerals, tectonics, natural resources and groundwater in the country. The oldest rocks in the region are part of the Ukrainian Shield and formed more than 2.5 billion years ago in the Archean eon of the Precambrian. Extensive tectonic evolution and numerous orogeny mountain building events fractured the crust into numerous block, horsts, grabens and depressions and Ukraine was intermittently flooded as the crust downwarped during much of the Paleozoic, Mesozoic and early Cenozoic, before the formation of the Alps and Carpathians defined much of its current topography and tectonics. Ukraine was impacted by the Pleistocene glaciations within the last several hundred thousand years. The country has numerous metal deposits as well as minerals, building stone and high-quality industrial sands.
The geology of Moldova encompasses basement rocks from the Precambrian dating back more than 2.5 billion years, overlain by thick sequences of Proterozoic, Paleozoic, Mesozoic and Cenozoic sedimentary rocks.
The geology of Belgium encompasses rocks, minerals and tectonic events stretching back more than 500 million years. Belgium covers an area of about 30,507 square kilometers and was instrumental in the development of geology. The extensive outcrops in Belgium became the standard reference points in stratigraphy as early as the mid-19th century. Some of them are internationally recognized features related to the Carboniferous and the Devonian periods. These rocks were folded by two orogeny mountain building events --the Hercynian orogeny, and Caledonian Orogeny. Paleozoic basement rocks cover much of the country and are overlain by Mesozoic and Cenozoic sediments.
The geology of the State of New York is made up of ancient Precambrian crystalline basement rock, forming the Adirondack Mountains and the bedrock of much of the state. These rocks experienced numerous deformations during mountain building events and much of the region was flooded by shallow seas depositing thick sequences of sedimentary rock during the Paleozoic. Fewer rocks have deposited since the Mesozoic as several kilometers of rock have eroded into the continental shelf and Atlantic coastal plain, although volcanic and sedimentary rocks in the Newark Basin are a prominent fossil-bearing feature near New York City from the Mesozoic rifting of the supercontinent Pangea.
The geology of Laos includes poorly defined oldest rocks. Marine conditions persisted for much of the Paleozoic and parts of the Mesozoic, followed by periods of uplift and erosion. The country has extensive salt, gypsum and potash, but very little hydrocarbons and limited base metals.
The geology of Afghanistan includes nearly one billion year old rocks from the Precambrian. The region experienced widespread marine transgressions and deposition during the Paleozoic and Mesozoic, that continued into the Cenozoic with the uplift of the Hindu Kush mountains.
The geology of Kyrgyzstan began to form during the Proterozoic. The country has experienced long-running uplift events, forming the Tian Shan mountains and large, sediment filled basins.
The geology of Uzbekistan consists of two microcontinents and the remnants of oceanic crust, which fused together into a tectonically complex but resource rich land mass during the Paleozoic, before becoming draped in thick, primarily marine sedimentary units.
The geology of Thailand includes deep crystalline metamorphic basement rocks, overlain by extensive sandstone, limestone, turbidites and some volcanic rocks. The region experienced complicated tectonics during the Paleozoic, long-running shallow water conditions and then renewed uplift and erosion in the past several million years ago.
The geology of Bulgaria consists of two major structural features. The Rhodope Massif in southern Bulgaria is made up of Archean, Proterozoic and Cambrian rocks and is a sub-province of the Thracian-Anatolian polymetallic province. It has dropped down, faulted basins filled with Cenozoic sediments and volcanic rocks. The Moesian Platform to the north extends into Romania and has Paleozoic rocks covered by rocks from the Mesozoic, typically buried by thick Danube River valley Quaternary sediments. In places, the Moesian Platform has small oil and gas fields. Bulgaria is a country in southeastern Europe. It is bordered by Romania to the north, Serbia and North Macedonia to the west, Greece and Turkey to the south, and the Black Sea to the east.
The geology of Slovakia is structurally complex, with a highly varied array of mountain ranges and belts largely formed during the Paleozoic, Mesozoic and Cenozoic eras.
The geology of Lithuania consists of ancient Proterozoic basement rock overlain by thick sequences of Paleozoic, Mesozoic and Cenozoic marine sedimentary rocks, with some oil reserves, abundant limestone, dolomite, phosphorite and glauconite. Lithuania is a country in the Baltic region of northern-eastern Europe.
The geology of Greece is highly structurally complex due to its position at the junction between the European and African tectonic plates.
The geology of Iraq includes thick sequences of marine and continental sedimentary rocks over poorly understood basement rock, at the junction of the Arabian Plate, the Anatolian Plate, and the Iranian Plate.
The geology of Italy includes mountain ranges such as the Alps and the Apennines formed from the uplift of igneous and primarily marine sedimentary rocks all formed since the Paleozoic. Some active volcanoes are located in Insular Italy.