Nature always tries to spend the less possible amount of energy. Due to this consideration, you won't be wrong if you say that the water will follow the path of a fault (or will dig a valley) which is much easier to erode because of the overworked rocks.

Of course this doesn't mean that all the branches of a drainage system can only be driven by faults. Water can also follow the pattern of discontinuities such as cracks.

In the extreme case where a rock formation is absolutely homogeneous, water will just be driven by gravity.

Kind regards

Ioannis Alexandrides

Is it possible that you posted this question in a bit a wrong field? Because it ended up being shown in the psychiatry/psychology field (maybe because the topic "depression" is used in both fields...).

If you look at the edges of continents, you will notice that  rivers are wider at the

mouth than at locations upstream.  Rivers " occupy "  spreading fractures and

"rifts" and faults.

so faults may be represented by river depending on the geology and geomorphology of the region. But it cannot be generalized as such. Thanks for you answers and time...

The course of a river may be guided by a fault because the weak plane is prone to rapid erosion and forming valley through which water can pass, But it is unfair to conclude that all rivers are flowing through fault planes. Geomorphology may guide the precise determination.

A short answer to your question is yes, but no exclusively.

I think  we cannot  say in general that a river will follow a fault.  River  can  develop in some sedimentary environment (such as fan dalta as far as i know) without fault. 

Ying, I don't understand your remark: "Rivers can develop in some sedimentary environment (such as fan delta as far as i know) without fault."

A fan delta IS produced by a river when it reaches open water.

Lets first separate the rivers as Bedrock (detachment limited) and Alluvial (Transport Limited). Alluvial Rivers flow freely in a large depression or valleys that might be related by faults but not necessarily or might be related folds or karstification. The position of their courses might be related topography or their hydrological power and sediment load.

On the other hand Bedrock Rivers are different. They are confined in narrow valley and this valley might be a shear zone, fold axis (sync or antciline), or lithological contact. It is clear that rivers like to erode weaker part of the basement. 

As a conclusion a drainage network of bedrock rivers is started to develop by initially consequent rivers, which follow the initial topographical slope (gravity) than it may migrate to weakness zones, and as tributaries of the consequent rivers the subsequent rivers started to developed that they usually follow structural features not only faults but also fractures and bedding etc. 

I hope I did not do it complicate. 

We can say in general that a river will follow the path of least resistance

from higher elevation to lower elevation.  It may follow a fault, rift, basin,

fold, or any other low spot in the surface of the land.  Rivers erode in the

higher elevations ( steeper gradient ), and deposit in the lower elevation

( meanders with shallow gradient ).

In an hard rock environment that is uplifted by regional tectonics large and small rivers  cut down along fracture zones, i.e. along joint and fault zones. This is typically shown in central Europe, as e.g. in the Eifel, where the country rocks consist largely of rather impermeable Lower Devonian slates, greywackes, sndstones and quartzite. During the uplift of the area since c. 700,000 years, little streams and rivers  have been cutting down on the six to eight structural trends known from joints and faults in the field, aerial photographs and satellite imagery. In addition, not only ordinary springs, but also thermal springs, Co2-springs and mineral springs are located in valleys that had been cut down in the uplifted hard rocks in the whole European Cainozoic Rift System. In addition, a highly interesting aspect of the two Pleistocene Eifel volcanic fields is that wherever magma rose below valleys, small or large valleys, the magma interacted with groundwater and erupted in an explosive fashion, i.e. erupted phreatomagmatically and formed maar-diatreme volcanoes. In larger streams and valleys these volcanoes erupted phreatomagmatically as long as magma row towards the surface. In much smaller valleys the magma erupted phreatomagmatically in a more or less long phreatomagmatic phase but then, usually changed in its activity and formed a scoria cone because the availability of groundwater had ended. This clearly shows that the more pronounced the hydraulically active fracture zone is in the hard rocks the more pronounced the valley usually is in comparison with its surrounding tributaries.

There is another interesting reason in respect to the formation of valleys in uplifted hard rocks:  groundwater flowing within hydraulically active fracture zones, joint zones and fault zones, has been dissolving some chemistry of the wall rocks of the fracture zones since hundred thousands er even millions of years already with the result that the immediate wall rocks have been altered, i.e. weather subterraneously, have been diasggregated a bit, and, therefore, weakened to some extent - we do not drink sterile groundwater when we drink unprocessed or processed groundwater. The chemical analyses shown on the labels of bottles of mineral water show what groundwater take out of the wall rocks of joints or faults. The longer groundwater moved through such fracture zones the more these fracture zones got weakened and are prone for developing into valleys during uplift and consequent forced incision of the valleys. 

Kind regards 

Volker Lorenz

For granitic terrains it is worth reading Twidale's work.

FWIW, rivers often cut across active faults in the Basin and Range province in North America.  I think it is fair to say that those rivers are more influenced by the relief caused by the fault than the fault itself.  Although some of the larger rivers in that region seem to be associated with geologic contacts and much older structural features.  Water follows the path of least resistance, which is all relative.

Yes, I can agree to that, but what about the direction of joints that cut across the ranges through which the impressive dry valley pass from one of the basins - of the Basin and Range province - to the next one?

It is very likely the rivers were there first in the US before the Basin and

Range formed sequentially from west to east across the western US.

Best guess is the Basin and Range began on the west coast around

59 million years ago, and has been forming a new one from west to

east every two to three million years, thus stretching the western US

and making it wider.  Prior to 59 million years ago, the western US

has an inland sea covering much of Utah, Nevada, and Arizona.

The grand canyon flowed in the opposite direction into Utah.   This reversed

direction at more recent times after North American rose, or the Oceans

became lower some time between 59 MYA and 6 MYA.  My guess is longer

rather than shorter.

In general - yes. Many rivers follow the fault zones. But many others - not. Moreover, if one looks in more detailes it often occur that the stream is shifted aside  from the fault plane or even from the fault zone. There are vany reasons for this. In planes the effect of gradual shift of the river valleys towardsthe right bank in the Northern Hemisphear - the well-known  Coriolis deflection. So, if a stream originated first along some weal zone it can happen that with time it will leave it. Another example: in rapidly uplifteng terrain where the bottom erosion prevailes, the stream will erode its valley where it was flowing when the uplift had intensified, regardless if there is a weak zone or not. So, you should be careful with equalizing river cources anв faults.

Michael Clark,

The Eocene rivers that drained the high topography that is now the Basin and Range were completely disconnected by the B&R extension.  You can find remnants of them at 7500+' in the Tahoe Basin and find section cut and exposed high above the modern rivers along the west slope of the Sierra.  While the paleorivers may have influenced modern drainage networks to some extent, they are clearly not a dominant control on modern fluvial systems.

Volker Lorenz,

The majority of faults in the B&R run approximately N-S.  The majority of rivers flow roughly E-W, draining the resulting topography.  Some of the major rivers are oriented N-S, but I think their location is determined by the convergence of colluvium from the adjacent ranges rather than being coincide with faults.  Some older faults associated with previous orogenic events (Nevadan, Sonoman, Antler, Laramide, and Sevier orogenies) definitely influence the drainage networks coming out of the ranges in some places (e.g. Highway 6 through the House Range).  But in general I'd say the modern drainage networks (and associated alluvial deposits) cut across the younger B&R normal faults and their course is not substantially influenced by the faults.

Not B&R, but still really neat: http://activetectonics.asu.edu/Images/Photos/wc_Phelan.gif

The Colorado River is the only one I know about that has reversed direction

of flow from heading North East into Utah, to heading  south west to the

Baha.   The dendritics are strange up top, they head in the wrong direction,

then when the gullies plunge off the edge into the grand Canyon, the 

water heads backwards to the dendritics to the south west.

Isolated Lakes include Lake Boneville ( now reduced to Salt Lake ) in

Utah, and a much bigger one was the Salar de Uyuni in Bolivia, and

at a higher elevation, and greater bottom surface area.

on all of them, if you hunt for them, you can still find the wave cut and benched

shorelines up on the mountain sides.

Bolivia even has a limestone reef in the middle of the Salar de Uyuni at 

over 10,000 foot elevation.

I grew up on one of the shorlines in Salt Lake.  It was awesome when I realized what "the bench" actually was... remnants of Lake Bonneville!

The Eocene river deposits I was talking about are stranded 1000'+ above Lake Tahoe and not associated with any modern fluvial systems.

You could find some general information in this document.

http://biotech.law.lsu.edu/katrina/govdocs/faults.pdf

Thank you all for your time and valuable suggestions... I learned a lot from your comments...

Rock mass along the fault-zone is weakened during the activity of the fault. As a consequence the fault alignment is more easily eroded than the flanks. Water by its inherent nature follows the easiest path and therefore chooses to flow along such weak alignments - whether fault zones or fracture zones.

However, this is not true for ancient fault traces that are healed.

Therefore, one needs to be cautious when generalizing on this.

Prakash Barman, with your question you really started an interesting discussion. I congratulate you for having started this discussion.

In my opinion streams and rivers follow in uplifted hard rock environments in many instances fracture zones, whatever they consist of: joints and faults, but there may be indurated sediments where some beds are suitable to get eroded by running water more easily than others. Look for the various trends of the fracture pattern in the hard rocks - plutonic, volcanic, metamorphic, indurated sediments and compare the trends of the fractures faults and joints with the trends of the various almost straight segments of valley bottoms, it does not matter if it is a river or a a stream that is flowing down the valley or if the valley is even a dry one - because of a change in climate conditions or if karstic activity caused subsidence of the groundwater surface below the valley floor. This opinion of mine does not claim, of course, that all faults and all joint zones are used by streams and rivers. This depends on the relationship of the tectonic evolution of an area with the resistivity of the country rocks towards erosion, the level of groundwater surface in respect to the surface water, and whereto the surface water of the drainage system is ultimately heading for.

In areas containing unconsolidated sediments the situation is of course quite different. There, the streams and rivers in principle follow the regional gradient. But in some intermontane basins and continental rift basins faults that show synsedimentary activity may also have an effect on the course and even incision of a stream or river.

Many thanks again

Volker Lorenz

Thank you Sir Volker Lorenz for the detailed discussion...

I think - following the discussion - the most important point to be regarded in the interplay of landscape evolution, river incision and deposition is TIME. Young active faults produce cascades, knick-points and discrete along-stream profiles of rivers, others simply choose the easiest way to erode into the basement. If you think of the Upper Rhine Graben, major faults parallel the river course. But river Rhine is depositing huge amounts of gravel (partly > 400m of Quat.), and changes its course frequently. Another point is the age of the landscape (formerly glaciated areas, new young rivers, old basement structures), in the North German Basin, the basement seems to have a "memory" of weak structures and re-uses old river beds after deglaciation. In my point of view, the time plays the second role after lithological and structural inheritance on river incision. By the way: also climate does. No water, no river, as in the Atacama.

Dear Prakash,

As many contributors stated above, rivers are very sensitive systems so that they will react, among others, to tectonic forcing. As Cengiz mentioned above, it is important to separate the bedrock and alluvial channels. The planform shape of a watercourse can be influenced by the tectonic activity in various ways. Probably you are more interested in bedrock channels, but if you also consider alluvial ones then our paper may be of interest for you: http://dx.doi.org/10.1016/j.gloplacha.2012.08.005

We have reviewed a large number of rivers in a neotectonically active (but very flat) region (Pannonian Basin) in terms of sinuosity and found interesting correlations.

Kind regards, Balázs

@Peter Dahlin

Ying might have referred to a fan (and not a fan delta sensu stricto) that can be related to a fault, however not parallel to the fault but quasi-perpendicular to that. If there is a hanging valley (even a small vertical displacement would do) that finally generates a fan, it could be due to tectonic activity. (Yes, this can be due to a temporary base level drop or to a postglacial setting as well; most probably you can observe typically the latter situation around you in Scandinavia.)

The river Hondo, border between Belize and Mexico, is another example of a surface river following a fault.

Yes, of course. Look at the course of the Ayayawardy River (Irrawaddy) in Myanmar. It follows precisely the Sagaing Fault for almost 200 km on land. Furthermore, it continues across the continental shelf and generally down the continental slope to the basin of the Andaman Sea. There must be many other examples elsewhere in the world.

I only read this question today and I read many of the answers, which most of them I agree with. It's obvious that fault (and tectonics in general) can control drainages and rivers patterns. However, there are other points of view, and aspects to consider, that one should adress when stating that a linear section of a river flows through a fault zone. First of all, this assumption  of river will flow along a fault if there is one is not always true. Secondly, flowing through a fault, do you mean an active fault or a non-active fault? because both scenarios are possible, and sometimes, the river could flow along a "dead structure"  (or a lithological contact, or a fold) and not along the active strands of a fault. Third, the interaction climate/ surface processes/ tectonics (type of structure and tectonics rate) and the river hidrodinamics, strenght power (and others) is higly important. I have worked in a an area for many years, where the river do not follow at all the main fault. The river  location (and alluvial plain)  flows throught a linear section for almost 100 km but seems to be controled by other factors than tectonics, and the river bank, which is linear for some km, at the end is controled by erosion and not by faulting. So, my advise is not to assume that this correlation is always the case, because in fact, when the bedrock geology is more complicated and when the interaction with tectonics and surface processes have distinct rates (lower tectonic rates and high surface processes rates, or high tectonic rates and low surface processes, as for instances no pluviosity) this correlation should be access with caution.

Not always, sometimes rivers and drainage system follow weakness zones like faults or other structures  i.e. structurally controlled...this also known as morphotectonic structure. On the other hand, some topographical features can formed as a result of differential erosion i.e .  where the lithology is the main factor..........

General morphological analysis are appropriate in the study of large areas, and the results are good only as a first approach. After this first phase, you need to validate in the field the obtained first level results, through detailed structural surveys.

in some case it's true, the river follow the fault line. however, when the river is perpendicular over the fault line we can seen a knickpoint in the profil of this river. we can also attribuate this knickpoint to lithology differentiation. it's important to examine the field reality. 

 Dear Zaagane,

You wrote: "when the river is perpendicular over the fault line we can seen a knickpoint in the profil of this river" This is frequently the case, but not necessarily always, depends also on the kinematic of the fault. Furthermore, it is especially not typical in case of alluvial rivers. Our study showed quite a nice variety of behaviour concerning the alluvial rivers in the Pannonian Basin. (The interested reader may find examples in the paper, see the attached link.)

Kind regards,  Balázs

http://dx.doi.org/10.1016/j.gloplacha.2012.08.005

They not only follow a fault, or a rift, they can flow inside the fault, or rift. In 2017, the Mississippi River became a lot lower for a 115 out of 120 mile long section of the river that is above the New Madrid Fault. The Fault ( Rift ) opened up, and the water filled the pore spaces inside the rift that was filled with sand and gravel. Eventually the silt and mud clogs up the pore spaces, and the water must again flow along the top of the fault (rift ) filling the river back up to it old flow elevations. Water flows inside rifts that are widening over millions of years. The flow rate during expansion accelerates, thus lowering the overall elevation of the river itself.