Gustav Kober's geosynclinal theory, proposed in the early 20th century, was a significant attempt to explain the formation of fold mountains (orogenesis) before the advent of plate tectonics. It built upon the concept of geosynclines as elongated, mobile depressions in the Earth's crust that accumulate vast thicknesses of sediments.

Kober's Theory Explained: Kober envisioned the Earth's crust as composed of rigid 'forelands' (Kratogen) and mobile 'geosynclines' (Orogen). He proposed that mountain building occurred in three main stages:

1. Lithogenesis (Sedimentation): Sediments accumulate in the geosyncline, causing it to subside under their weight. This process continues for millions of years, forming thick sedimentary sequences.
2. Orogenesis (Mountain Building): Lateral compression, originating from the movement of the rigid forelands towards each other, squeezes the sediments within the geosyncline. This compression causes the sediments to fold, fault, and uplift, forming mountain ranges. Kober identified two marginal mountain ranges (Randketten) and a central stable mass (Zwischengebirge) within the geosyncline, which remained relatively undeformed.
3. Gliptogenesis (Sculpturing): After uplift, erosional processes begin to sculpt the newly formed mountains into their present-day forms.

Evaluation of Kober's Theory:

Strengths:

• Explains Linear Mountain Ranges: Kober's theory successfully explained the linear arrangement of many major mountain ranges (e.g., Alps, Himalayas) and their association with thick sedimentary sequences.
• Accounts for Folding and Faulting: It provided a plausible mechanism for the intense folding and faulting observed in mountain belts, attributing them to lateral compression.
• Concept of Geosynclines: The concept of geosynclines as zones of intense sedimentation and subsequent deformation was a valuable contribution that laid groundwork for later theories.

Limitations and How Far it Explains Mountain Building: Kober's theory, while influential for its time, has significant limitations, especially when viewed through the lens of modern plate tectonics:

1. Lack of Driving Mechanism: The most critical weakness is its failure to explain the fundamental cause of the lateral compressive forces. Kober vaguely attributed it to the contraction of the Earth, a hypothesis that lacked a robust physical basis and was later disproven.
2. Limited Scope: It primarily focused on fold mountains formed from geosynclinal sediments and did not adequately explain other types of mountains, such as volcanic arcs, block mountains, or rift mountains.
3. Oversimplification of Crustal Dynamics: The rigid foreland and mobile geosyncline model is an oversimplification. The Earth's crust is far more dynamic, with large-scale plate movements driving tectonic processes.
4. No Global Framework: Kober's theory was a regional explanation and lacked a comprehensive global framework to connect mountain building events across different continents.
5. Inconsistent with Modern Observations: Modern geological and geophysical data, particularly from seismology and satellite geodesy, strongly support plate tectonics, which provides a far more comprehensive and accurate explanation for mountain building through processes like continental collision, subduction, and rifting.

Conclusion: Kober's geosynclinal theory was a pioneering effort that correctly identified the association of thick sedimentary basins with mountain ranges and the role of compression in their formation. It provided a useful descriptive model for many mountain belts. However, it falls short in explaining the ultimate driving forces behind mountain building and lacks the predictive power and global applicability of plate tectonics. Therefore, while it explains some aspects of mountain building (like the folding of sediments in elongated basins), it does not provide a complete or accurate explanation for the entire process or its underlying mechanisms, especially when compared to the robust framework offered by plate tectonics.