How did the Fjords form?
Published: 15 February 2020 (GMT+10)
Today’s feedback is a question from C.O. of Norway about the origin of fjords.
Did the ice form the fjords or were they already there and the ice then filled them? Was it the continental plates crashing into each other? My family has been avidly discussing this since our son was questioned about it recently.
CMI geologist Dr Tas Walker responds:
In some ways all those ideas apply. Let me explain. A 1992 paper entitled “Quaternary erosion in the Sognefjord drainage basin, Western Norway”1 provides a useful overview on fjords. This was published in Geomorphology by Atle Nesje and others. The information was subsequently posted on the website Fjords.com. Dr Nesje is Professor in Quaternary Geology at the University of Bergen, Norway. Sognefjord (figure 1) is the largest, best-known fjord in Norway, and the longest fjord in the world. The dates of millions of years quoted in the paper can be reinterpreted within biblical history along the following preliminary lines:
Table: Preliminary reinterpretation of long-age dates into a biblical historical framework
|Long-age dates2||Corresponding biblical history|
|Palaeocene to Miocene||Said to be 66–5.3 million years ago||Almost certainly the second ‘half’ of the Flood (about 4,500 years ago), covering most of the time the floodwaters were receding off the continents, over a period of some 7 months.|
|Pliocene||5.3–2.6 million years ago||Most likely very Late Flood with the last of the waters receding, although the last portion of this period may have been very early in the post-Flood era.|
|Pleistocene||2.6 million years to 12,000 years ago||Post-Flood. Probably equivalent to the first 700 years (approximately) of the post-Flood period which corresponds to the post-Flood Ice Age.3 The Flood ended approx 4,500 years ago and so the Ice Age ended about 3,800 years ago.|
|Holocene||12,000 years ago to the present||After the Ice Age, from approximately 3,800 years ago to present.|
By water or by ice?
The 1992 paper explains that fjords are found in valleys where current or past glaciations extended below the present sea level, and the glacier carved its typical U-shape into the valley. When the glacier retreated, the sea filled the valley, which has a narrow, steep sided inlet, sometimes deeper than 1,300 metres. The terminal moraine pushed down the valley by the glacier has been left underwater at the entrance of the fjord, making the water shallower there than in the main body of the fjord behind it. For Sognefjord the seabed is covered by some 200 metres of sediments such that the bedrock is some 1,500 metres below sea level. Sognefjord is up to 6 km wide.
Concerning the actual processes that formed the fjords the paper begins:
“… the origin and processes related to this feature have been discussed for almost a hundred years. … This debate has mainly focused on the classic fjords and fjord lakes in Norway and Canada. Most authors agree that there has been a clear glacial-erosive influence on the fjords, but the importance of glacial activity relative to such other processes as tectonism and fluvial erosion has not been clear.”
Perhaps there is some northern hemisphere bias here, because one excellent place for fjords is Fiordland National Park in the South Island of New Zealand, a UN World Heritage Area since 1986. This has 14 fjords spanning 215 km of coastline, including the famous Milford Sound, which Rudyard Kipling called “the Eighth Wonder of the World”.
The two processes discussed in the paper are water erosion (in the form of large rivers, a ‘fluvial’ processes), and glacial erosion. It’s generally accepted that both processes were involved in forming the fjords, with discussion revolving around how much of each one.
The other process mentioned is tectonism, which is basically movement of the earth’s tectonic plates, up, down and sideways. This pushes huge blocks of rock together forming the continental structure, and fractures the crust forming faults and joints in basement rock. On a map of the area (figure 2) the structure of the faults can be seen in that that the waterways run in two preferred directions: north-east to south-west, and north-west to south-east. This is typical of an area that has experienced earth movements that move and crack the basement.
Structure of the Baltic Shield
The geology of the area provides insight into this basic tectonic structure. The Scandinavian Peninsula, where the fjords are, is part of a large segment of the earth’s crust known as the Baltic Shield, which is composed of ‘old’, crystalline metamorphic rocks. “Crystalline and metamorphic” indicates they have been altered by pressure and temperature as a consequence of large-scale crustal movement. It is considered that the Scandinavian Peninsula is built of large blocks of rock, hundreds of kilometres long, called allochthons. The idea is that these enormous blocks were moved from their original position and pushed together to form the peninsula.
In the case of the Baltic Shield, it is assumed that the allochthons were pushed sideways from the north-west against the Baltic Shield, expanding its size. This basic north-east to south-west structure of the Baltic Shield can be seen in a geologic map of the shield (figure 3). The movement of the rock that formed the Baltic Shield is likely to have occurred very early in Noah’s Flood during the initial high-energy eruptive stage. This was different from movements of the crust that created the structural faults and fractures, and these would have occurred later in the Flood. The faults and fractures formed at this time likely guided the development of the fjords, which formed even later, as the continent was uplifted and the ocean basins sank.
Large portion of Fjord formed before Ice Age
Concerning the formation of the Sognefjord the paper says:
“The Sognefjord is presumed to follow a preglacial (original / paleic) river system.4 In many places the [preglacial] paleic surface is preserved more or less unaltered and the paleic surface and the present landscape commonly occur together … . The consistent and gradually rising summit level eastwards along the Sognefjord … may therefore be regarded as remnants of the [preglacial] paleic surface.”
In other words, the large scale shape of the landscape in many places has not been greatly affected by Ice Age glaciation. This means that the basic form of the landscape would have been carved by the waters of Noah’s Flood as they receded, which they did in two phases. First, they covered the whole continent in wide sheets and carved the large, plateau, gradually rising to the east. Based on experience on other continents, kilometres of rock would have been removed from above the present land surface, during this phase. And second, the water flow would have reduced, but still flowed in wide channels, eroding the preglacial river system that the paper refers to. That river system would have been influenced or controlled by the existing geological structure, including joints, faults and cracks. As mentioned, this structure would have been formed by processes earlier during the Flood.
This means that the main effect of the glaciers was on the already existing, pre-glacial valleys. Fjords are over-deepened, especially where the mountains are high. Such over-deepening is not only observed at fjords, but in some valleys alongside high mountains that had an ice cap. This over-deepening is likely caused by basal meltwater at high pressure as a result of the thickness of the ice.
In calculating the volume of material the glaciers actually eroded the 1992 paper says: “However, the preglacial valley floor is difficult to reconstruct accurately along the present fjord … , and this introduces some uncertainties when calculating glacial erosion.” In spite of the uncertainties, the authors estimate that an average of some 610 m of rock was eroded from the valley of the Sognefjord by the glacier during the Ice Age. In other words, the glaciers did not carve the fjord but only deepened the large valley that had already been carved by fluvial process—namely the receding waters of Noah’s Flood.
In summary, the main geological structure of the region formed early in Noah’s Flood, as huge allochthons (i.e. enormous blocks of rock) accreted sideways onto the edge of the Baltic Shield, enlarging it. The principal shape of the landscape, especially the large flat plateau, was cut by the receding floodwaters during continental uplift. The basic river system was also cut by the receding floodwaters, but during the later channelized flow phase. The existing geologic structure in the crystalline metamorphic rock, including fractures, faults, and fissures, would have guided the flow of this river system, influencing the layout of the valleys as they were carved initially. During the Ice Age, glacial ice filled those valleys, deepening and enlarging them, and pushing glacial debris to the mouth of the fjord.
Creation Ministries International
References and notes
- Nesje, A., Dahl, S.O., Valen, VG., and Øvstedal, J., Quaternary erosion in the Sognefjord drainage basin, western Norway, Geomorphology 5:511–520, 1992. Return to text.
- The long-age dates listed are from the international Chronostratigraphic Chart v 2019/05, International Commission on Stratigraphy, stratigraphy.org. The long-age numbers change from time to time. Return to text.
- Oard, M.J., An Ice Age Caused by the Genesis Flood, Institute for Creation Research, El Cajon, CA., 1990; Available on creation.com store. Return to text.
- Paleic refers to the original land surface as it existed at the opening of the Ice Age and before glaciers formed the present topography. Return to text.