406,734 views
38 votes
38 votes
Why are braided streams common in sedimentary rocks before the arrival of plants on land ?

User Hemanath
by
3.1k points

1 Answer

19 votes
19 votes

Answer:

Braided rivers have a multithreaded plan form comprising many confluences and diffluences (Miall, 1977). Braid bars and channels can be classified as a hierarchy depending upon their relative size, and three orders of braiding can be seen in proglacial rivers with constant discharge. First-order braid bars are those largest bars which are separated by major channels. First-order bars are made up of a series of smaller, second-order braid bars, which are separated by smaller channels. Third-order braid bars are contained within second-order bars. Complexity of braid pattern is, however, strongly stage dependent, with rivers losing their braided character during peak flood conditions. Braid bars, mid-channel bars, unit bars, and islands have been described in braided river systems on a range of scales ranging from meters to kilometers. All bars are subject to dissection , remobilization, and migration by the appropriate discharge magnitude and frequency (Miall, 1977, 1983).

Step-by-step explanation:

User Adnan Zameer
by
3.2k points